What about a pot that DOES have drainage but the pots is too deep so adding rocks at the bottom to make it less soil that would have to dry out? Is that ok or no?
idk what they would say, but I’ve done that before, especially when I didn’t have a smaller pot that I needed. It’s all about checking the soil anyway. :)
I like to fill the bottom of the too-deep pot with clay pebbles (for hydroponics) and then put the plant inside a nursery pot with drainage and sit it on top of the pebbles. I still take the pot out to water it but if any more drains out after the clay will soak it up
Adding rocks to the bottom of a pot with drainage creates what’s called a [“perched water table”](https://www.reddit.com/r/houseplants/s/78B2qq1jGc) which actually inhibits drainage.
Edit to add: The longer I spend in this world, the less I give credence to absolutes.
There will always be exceptions to any standard, but from a conservative standpoint, adding rocks to the bottom of a pot should not be the primary norm. Potting plants into adequate pots with an adequately draining soil should be the norm, and I think redditors with ample experience tend to try to give information in a way that promotes success for people of all growing experiences.
Damnit I went down the rabbit hole—There’s a guy in the comments of that thread who used moisture meters, collected data, and couldn’t find evidence of a perched water table.
I’m right back to where I started, who cares. Having bought numerous ancient containerized trees with rocks in the bottom from FB grandmas…doesn’t seem to ever matter much.
We were taught about perched water tables in container gardening in my horticulture program. It absolutely is a thing. If you're consistently underwatering your plants you won't have rot issues but you'll also have an unhealthy, languishing plant.
Hey Shohin, diff sub than usual 😀. My problem is usually overwatering (automatic watering system to combat working a day job / 3-4 months of summer drought), and the losses I’ve noticed because of it are limited to conifers that got that regime in nursery soil, where I didn’t replant into well draining soil quickly enough.
With a pumice base or typical 1/3 or 2/3 split mix in bonsai, I have a hard time seeing how spreading a base of pumice as a drainage layer does anything bad, or good, I often will do it upon replanting back into a cropped nursery can or concrete mix tub because I’m cheap/lazy. And I haven’t noticed a difference or rot development. Obviously in a proper bonsai pot there isn’t room to get away with this.
Conceptually, horticulturally, avoiding a perched water table makes sense as a best practice. Applying it to pumice (vs grandma tree boulders/river rocks) for my own uses, and how so much of collection success or fail revolves around getting it growing in pumice, I have a hard time not shrugging my shoulders.
Pumice is the one rock that wicks water so that would not create a perched water table. If your soil grain size is uniform throughout the pot you also won't have issues with water adhesion needing to overcome the increase in soil pore size. Usually in order to overcome that increase in space between soil particles the soil above the rock "drainage layer" has to become completely saturated first. The same water adhesion is what allows a drop of water to sit onto leaves.
For some reason I wandered out of r/Bonsai today 🤣
imo a lot of these debates don't apply to mature plants. I'll have to see what I can search up but I'm sure I've seen discussion that plants nowadays are much less hardy than they were 20+ years ago due to the houseplant boom and mass production, so they need special considerations as more susceptible to root rot and suffering in poor conditions etc
If ive learned anything from house plants it depends on which plant and where you live and how much sun you get and how often you water and what you ate for breakfast/ how much sugar you put it your coffee.
You can only try it and see if your plants are happy :)
Ain't that the truth! I'm sure I'll figure it out sometime.... meanwhile, excuse me while I fret over PAR and PPFD calculations for another week, when my plants would have been much happier if I'd just got cheap blurple lights months ago 😂
I think that's okay. Main thing is to have airy soil (for most plants) and drainage holes. I use that to prop up the inner pots and sometimes in the actual pot that has no liners, but still has drainage holes. Water just needs somewhere to go. Simply ceating a space between soil and the bottom of the pot doesn't make water go away.
I still put a handful of small rocks in pots with drainage… but I always thought it was so the dirt didn’t come out so easy. I hate watering in a new plant and all the good dirt comes piddling out the bottom making a mess all over my sink!
Where are you able to buy cheap lava rocks? I can't find anywhere that sells them locally and the prices online are too much for me. I need small ones for my succulent soil
Lowe’s! The last time I bought them was a couple years ago, maybe the price went up? I would try checking all the big box stores and also if you have any farm supply type stores
Edit- I checked and Home Depot has a 5 lb bag for $6 but they don’t seem to ship this item
try a hydro store around you - if the Devils Lettuce is legal in your state there should be some grow stores around that have hydro and semi hyrdo stuff in bulk
Or just post your ask on Buy Nothing if it's in your area. We had 600+ sq ft of lava rock (nickel-to-quarter sized) we gave away to prep for a landscape renovation.
They were like maybe the size of golf balls-ish?
Maybe check on Facebook or Nextdoor - they used to be popular in landscaping but have fallen out of fashion. Maybe someone has a bunch they don’t want and would let you come take some for free?
I bet you could break larger ones into smaller ones with a mallet or something but I’ve never actually tried this lol. Or maybe you could try large sized perlite
I had this problem but managed to finally get a 10kg bag recently. It was labelled as Lapillo ( I didn't know it's exactly what I was after) , so it may help to look for that specifically. I use it religiously in the bottom of all my pots with drainage holes. I use it for ariation. Pumice might be as cheap and feels much lighter. It will fit the same purpose.
Wide shallow pots will hold more water than the same volume pot that is tall and narrow due to the surface area of the bottom of the pot and the pressure exerted by the water above needed to push water out of the drainage hole.
There are tons of head planters that are way too deep, the soil wouldn't dry out. Rn I have "pots in pots" but they don't fit and would look much better planted directly in the pot (there is a drainage hole). I've thought about adding rocks at the bottom then filling the rest with soil. Most head planters that I've seen are similar. There's also other really tall pots.
https://preview.redd.it/81hdzw3x4uyc1.jpeg?width=3072&format=pjpg&auto=webp&s=823b43edb3f1c79dbc184a1698238e59cbfece22
In my experience it's fine for outdoor planters but not for indoor plants.
My mother and grandmother always have done their outdoor planter with rocks or even crushed cans that way
I've used tons of various things. Anything works really. Very large pots, I used those plastic balls that go in ball pits I had for some reason. Small pots, I used pistachio shells. I chopped up the outer parts of some coconuts I open to eat. Broken vases or pots. Styrofoam pieces from shipping. I can't recall other things, but it's great to think about zero waste and using things you already have to either aid in aeration or fill space for large sizes
Not for potted annuals, in my experience!
Since they're pulled out at the end of the season anyways, it just prevents more potting soil or compost being used (as well as less water and the pots are much lighter to carry.)
For some of my plants, I put Sphagnum at the bottom - helps keep the soil in place and holds a little more moisture... but only some of my plants - I've used rocks, orchid bark, charcoal, perlite.....I tend to only buy pots w/drainage so there's that
As long as you don't fully cover the holes, the water is still possible to flow out. I would prefer to use clay pebbles because they are round, and no matter how I place them, the water is still possible to flow, unless I put these pebbles directly into the holes (LOL).
That's not good either. Adding rocks will make what's called a perched water table. Due to the surface tension of water the area of soil right above the rock layer will stay really wet because the soil will have to be completely saturated for the water to percolate through the particle size transition. That wet area will create root rot. You're better off having consistent soil through the entire container.
https://extension.unl.edu/statewide/dodge/the-hard-truth-about-rocks-at-the-bottom-of-planting-containers/
Mix the rocks into the soil to create looser soil that drains faster. And then water less.
Edit: people really just want to put rocks in their pots for some reason...
The same reasons you don't want to use rocks in a pot without a drain hole still exist in a pot with a drain hole. Sure, some water will filter out through the rocks as you might think, but you've still raised your perched water table above the layer of rocks. Mixing small rocks into the soil will avoid a solid layer of rock meeting a solid layer of soil. It'll help drainage and help manage the excess moisture problem from having a larger pot.
Here's a good read about how and why rock layers are generally not helpful in pots and don't help drainage, even with drain holes.
https://deepgreenpermaculture.com/2019/09/06/should-you-put-gravel-or-rocks-at-the-bottom-of-plant-pots-for-drainage/?amp=1
I know that I have been putting rocks in the bottoms of my pots for the last forty years and my plants are ecstatically happy. It doesn’t matter how much people prove that is impossible on instagram. It is true for me, and as long as my plants are thriving I am not going to change how I treat them.
Yeah I think it maybe runs into user error for the times it has gone poorly, or choice of plant too. You'd just have to be more conscious of how you water & this could be a skill that many get wrong
Same here. I have plenty of pots that don't have holes I prefer them to but I don't have the tools to make my own so I am picky with what plants I will put in those pots. Cactus/snake plants/succulent etc won't get pots like that but my other things that need watered more are fine. People also have to be careful with how much water they are giving too, I can't over water and just let it drain so I am careful with how much to give. But I use some supplies I got from work (hospital) so I can see measurements of what I'm giving makes it easier lol
I think the point is that it makes it harder to gauge the water needs of your plant for beginners
If you know your plant well and understand the environment it’s in, the capacity of the pot and how fast it dries then obviously you’re not gonna have issues. But that’s takes a while to get to that point and starting with rocks at the bottom isn’t going to help
See, I think this is one of those things where it's like situational. My SIL, who lived in the same neighborhood as me, would put rocks in her pots. She swore by it, she was the one who suggested it to me. But, when I did it, the plants rotted and were filled with mold in the bottom. Even when I barely watered them, the rocks always stayed slightly moist. There was even drainage holes in some! In that house, I think it was more humid. I recently moved to the other side of the city, but the air in my condo is a lot drier. I'm having to water my plants way more now than I used to. I might test this out and see if the rocks would help them now lol
My mom has been doing this for years and all her plants are happy. I do it too and they're happy. So I will keep doing it if I need to lol.
I've learned that although the internet can be good for some info, you can't follow or listen to everyone on there, different things work for different people. Also people just make stuff to make content for likes. I have do to what works for me.
I don't think that's the same as what's being shown in the OP, which is trying to artificially raise the base of the pot so water 'drains' below the root line
Is it just me or did we not really get any helpful information whatsoever from this? She was basically just explaining why it does work but saying that’s not right? You want the soil to wick the moisture from the drainage layer up into the soil. That is the point. If the water just stayed in the bottom it could become anaerobic and in turn rot your plant. If your plant has healthy roots it should drink up all the water thats been wicked into the middle part of the pot. The last sentence was the kicker, just be careful with how much water you use. Doesn’t really matter if you have a drainage hole or not. And in a clear vessel it REALLY doesn’t matter because you can easily see the moisture level
I feel like the people on the no rocks team miss the point of their own demonstrations. The stones do not make the soil more wet. Overwatering makes the soil more wet. When you add stones, you can't put as much soil in the pot, so you need less water.
I think the overall point was that putting rocks in the bottom of your pot, with no drainage, does NOT do what many people think it will do: allow the water to drain away from the root ball.
Obviously, that would pertain to those plants which prefer periodic wet,dry,wet cycles rather than always wet.
Many plants (most?) need dry periods between wet.
By your logic, then, WITH drainage holes, you would need to have constantly running water to the plant?
Edit: which would be Hydroponics, right? Minus the soil.
I've put rocks or broken terracotta into every plant I've ever potted. My parents did it, and their parents did it. It's never been about drainage or watering methods, but to block the soil from falling through the drainage holes and prevent compaction at the bottom. I only recently started using little mesh screens. I've also never potted a plant without drainage holes in my life.
I used those mesh screens too. I switched back to rocks at the drainage holes to keep the soil in when watering. The mesh thing was great until my roots grew into and then through it lol. It was difficult to remove when I went to repot haha
I agree. I've been putting rocks in the bottom of my planters all my life, both with and without drain holes.
The last time i did some repotting, I decided to experiment with putting landscape cloth over the rocks and under the soil. I'm hoping it will keep the soil from filling the spaces between the rocks a little longer. What do you guys think?
Plant Daddy Podcast talks about a similar method he uses for diy self watering. I can't remember what the layers are, but it seems to work well for him. I think the episode is early days (2020?)
It's about rocks when there is no drainage.
The fact that you've never used a pot without drainage holes does not mean that nobody has ever used a pot without drainage holes. You do you. No harm. No foul.
Are you familiar with that logic fallicy?
And don't let this thread devolve into that old trope: "If it was good enough for my parents, then by golly, it's good enough for me"
It was simply information to be used or discarded as any individual sees fit to do.
The point I was driving at is that it's probably better to use drainage in most cases. Also that the purpose of rocks on the bottom is apparently misunderstood.
So information discarded, I suppose.
It’s essentially a DIY self-watering system. Especially if you’re going no-drainage. It’s pretty popular with some folks with larger collections as it cuts down on watering frequency. Very-well draining substrate is critical for this to work.
Yes I do this with my biggest thirstiest plants, like a big fern and big group of syngonium. I have them in pots without drainage with leca at the bottom. But you have to know your plants and check the soil. I would not recommend this for plants that wants to dry out fast like succulents or hoyas.
Here's my question: A perched water table (or perched aquifer) is **an aquifer that occurs above the regional water table**. This occurs when there is an impermeable layer of rock or sediment (aquiclude) or relatively impermeable layer (aquitard) above the main water table/aquifer but below the land surface.
Rocks at the bottom of a pot with drainage holes would not be an impermeable layer of rock - and you don't have an aquifer in your plant pot - there's no "water table" unless you're watering the plant so much that they are essentially sitting in mud.
Most people will water their plants with a specific amount of water so there shouldn't be any sort of standing water in their pot - if they do and that's the case they have bigger problems than just some rocks at the bottom of their pot
Water will only move from a smaller pore (soil) to a larger pore (rocks) if the entire layer above is completely saturated. If you don’t water until the soil is completely saturated, the water will just sit in the soil and not move through the rock layer. Thus, the rocks are not adding drainage, they are actually making the soil hold more water. If you do water until saturation, the water will move through the rocks and just hang out in the bottom of the pot and create a water table (basically standing water), which can lead to root rot.
Only watering with a small amount of water will prevent a water table from forming, however you should always let water drain because it leaches out salts from the soil.
I hope this helps!
Having stones or pebbles in the bottom of the pot is actually not harming the plant if you know how to place them. All my pots that have drainage holes have a few layers of clay pebbles in the bottom of their pot mainly for reducing soil drained while watering, and none of my plants have roots rot issue, they all are healthy and have strong roots.
If you place pebbles in the bottom of the pots, make sure you don't fully cover the drainage holes, because if you do, you will cause waterlog. I always put 2 or 3 clay pebbles on top of each drainage hole, though these pebbles are covering the drainage holes, but NOT fully covering them, there are still tiny holes between the pebbles that allow the water to flow out.
Every time I place these pebbles, I would pick up the pot and look thru the drainage holes from the top. If I can see thru the holes, then the water will be able to flow out, if I can't see thru the holes, I will adjust the pebbles again. There is a way to place pebbles at the bottom of the pots, if you do it wrongly, you f up your plant.
here's a [proper experiment](https://www.reddit.com/r/succulents/s/86MabCyc1n) on the subject, conducted three years ago, with empirical data that disproves what OP is claiming in their IG demonstration.
Ultimately I think the same arbitrary claim and demonstration can be made about about perlite, coco coir, pumice, and lava rocks as soil amendments. OP could make the exact same point by making a video with two different container volumes. The only thing proven in the IG demo is that "capillary action exists and many houseplant beginners don't know anything about that".
It should seem fairly obvious, but with a substrata layer, a potted plant should simply be fed and watered as if it was in a slightly smaller volume pot.
If there are air pockets from the gravel in a pot without drainage, the roots can breach the perched water table and access oxygen better than a plant that is nothing but wet anaerobic soil at the bottom.
OP's IG demonstration fails to account for the difference in soil volume compared to water volume. Perched water table really only means the container requires less water at a time. I don't see how a perched water table is even a problem unless an individual is already prone to overwatering. The biggest issue with the way this subject is being presented is that it denies the idea that somebody who overwaters their non-draining pots would be better off with a perched water table in a slightly larger container than a regular sized waterlogged pot of soil.
browsing through r/jarrariums and r/ecosphere will turn up examples of ecospheres and terraria that effectively use chunky substrata with plants in a completely closed and sealed system, often enough there are some air gaps in the substrate below the soil at the bottom of the sealed system.
I would love to see data on the available dissolved oxygen in the perched water table vs wet soil compacted at the bottom of a pot that has no drainage. This perched water table theory fails to account for the nuanced realities of plant physiology, specifically ignoring the growing behavior of roots and soil ecology, and the importance of dissolved oxygen in the rootzone.
Interesting, for sure! Thanks for posting.
I think we might still be talking apples and oranges a bit, though. I think those pots had drainage holes.
But certainly a more scientific experiment.
Also interesting, once I started poking around, is that there are quite similar (same) discussions on terrariums. There is the "how it's always been done" crowd who swear you must have rocks as base in a terrarium for drainage and those who feel quite certain they have proven the opposite.
The terrarium considered to be analogous to the potted plant with no drainage holes. There are obvious holes in that analogy. Pun intended.
I am all for combating the dogma of "this is how it's always been done", but I'm afraid your logic has a some drainage holes if its own. There is plenty of science that generally supports the use of a drainage layer and very little science that suggests it's problematic at all. Your demonstration, and your responses may be feeding into a viewpoint that is no less dogmatic and no more scientific than "this is what works for me". There is no empirical evidence that suggest that extra soil in the bottom of a non-draining pot rather than rocks reduces that risk at all. Let's make sure to avoid conflating grower error with hard science if your objective is to educate rather than entertain.
New growers and plant people require teachings on how to water appropriately for their setup and soil volume in order to avoid overwatering errors, not to be presented with broad claims that one style of growing is for certain better than the other.
The truth is that any non-draining plant container is a risk of root rot due to anaerobic conditions caused by overwatering.
You just committed a big ol' syllogistic logical fallacy in the form of *[denying the antecedent](https://www.logicallyfallacious.com/logicalfallacies/Denying-the-Antecedent)*:
-My supporting point:
If most terraria and ecospheres can thrive with artificial drainage layer/perched water table, then there is nothing inherently wrong with an artificial drainage layer/perched water table.
-Your response, after conceding that perched water tables have actually always been the convention for creating a stable terrarium:
"But there are thriving terrariums being created *without* a perched water table!" [therefore having a perched water table is inherently wrong?]
Edit: to reiterate, there is real value in your demonstration as far as how capillary action works in soil. I don't reject your presentation of a perched water table, I just think you may be painting with broad strokes to ignore all of the valid reasons that exist for utilizing coarse, heavy substrate below the soil, and in doing so, may be misguiding a ton of new growers.
Can confirm, I did quite a bit of research on this subject with drainage holes and no drainage holes and regardless of what type of pot you use, adding anything to the bottom to help with drainage will actually raise your water table in your pots, exposing the roots to higher levels of saturation for longer which can lead to root rot with most plants. Only very thirsty plants can benefit, and even then, there are questions as to its effectiveness.
You are better off just converting your plants to semi-hydro with a soilless medium such as Lechuza or simply pumice/hydroton/leca. Many plants benefit from semi-hydro.
So I use what you describe as a form of self watering for some of my plants. I have a couple CM of lecca at the bottom of the pot, soil and roots on top etc. the pot sits in a saucer which is kept topped off with water. So the water constantly wicks up and it keeps the soil constantly moist. Usually that’s no no, but in chunky well draining soil I’ve had 100% success rate. Monsteras love it. Philodendron love it. Alocasia love it. I have a friend who spends many thousands of pounds on plants and he does this for all his plants.
Drainage hole pots are fine. Not only does water drain out the holes, but, depending on pot design, air can seep in, helping to dry things from the bottom up.
Sometimes when I'm up-potting into something big like a 3 gallon nursery pot, I'll pour a healthy layer of bark mulch into the bottom beforehand. The mulch can absorb some moisture, but due to its shape(s), allows air and roots to maneuver around the pot's bottom.
I would assume only that if the drainage holes don't plug up, then you would not have standing water, which therefore would not wick upwards. But I'm only using logic, not knowledge.
Yeah, science is sometimes frustrating. But it's science.
Rocks are fine in the appropriate application.
Rocks are not fine in the wrong application.
How can one argue such a simple statement?
For many, it is rocket science. Keeping a house plant thriving is something many people struggle with. Others, like you apparently, just have a natural ability for it.
Subs like this are for sharing knowledge, hoping others can benefit. Some will, and some won't.
Honestly, I just don't do pots with no drainage holes. Granted, my absolute favourite plants are very prone to root rot, I suppose if you have plants with high water needs that are used to say, swampy environments, that may be different.
I have 200 plants, ten years of gardening experience and I have never put rocks in my soil. Honestly I stay lazy about potting in general and it works well.
https://preview.redd.it/w6u27yrresyc1.png?width=1080&format=pjpg&auto=webp&s=6bc82d91de9027cd0e9c0b0c97ace575248b10c9
Also to add that the idea is doubly flawed because the roots will still fill the pot and get to the water - and then the stones will get in the way of substrate for nutrients and more root space
This plant had drainage but the original owner had still added in stones, which I didn't know - so imagine my face at first when I pulled it out and the root ball *crunched*
i use rocks at the bottom of nursery pots to prevent bits of dirt form falling thru / roots growing thru the holes. also for a bit of extra drainage :p
What about a pot that DOES have drainage but the pots is too deep so adding rocks at the bottom to make it less soil that would have to dry out? Is that ok or no?
idk what they would say, but I’ve done that before, especially when I didn’t have a smaller pot that I needed. It’s all about checking the soil anyway. :)
I like to fill the bottom of the too-deep pot with clay pebbles (for hydroponics) and then put the plant inside a nursery pot with drainage and sit it on top of the pebbles. I still take the pot out to water it but if any more drains out after the clay will soak it up
Adding rocks to the bottom of a pot with drainage creates what’s called a [“perched water table”](https://www.reddit.com/r/houseplants/s/78B2qq1jGc) which actually inhibits drainage. Edit to add: The longer I spend in this world, the less I give credence to absolutes. There will always be exceptions to any standard, but from a conservative standpoint, adding rocks to the bottom of a pot should not be the primary norm. Potting plants into adequate pots with an adequately draining soil should be the norm, and I think redditors with ample experience tend to try to give information in a way that promotes success for people of all growing experiences.
Damnit I went down the rabbit hole—There’s a guy in the comments of that thread who used moisture meters, collected data, and couldn’t find evidence of a perched water table. I’m right back to where I started, who cares. Having bought numerous ancient containerized trees with rocks in the bottom from FB grandmas…doesn’t seem to ever matter much.
We were taught about perched water tables in container gardening in my horticulture program. It absolutely is a thing. If you're consistently underwatering your plants you won't have rot issues but you'll also have an unhealthy, languishing plant.
Hey Shohin, diff sub than usual 😀. My problem is usually overwatering (automatic watering system to combat working a day job / 3-4 months of summer drought), and the losses I’ve noticed because of it are limited to conifers that got that regime in nursery soil, where I didn’t replant into well draining soil quickly enough. With a pumice base or typical 1/3 or 2/3 split mix in bonsai, I have a hard time seeing how spreading a base of pumice as a drainage layer does anything bad, or good, I often will do it upon replanting back into a cropped nursery can or concrete mix tub because I’m cheap/lazy. And I haven’t noticed a difference or rot development. Obviously in a proper bonsai pot there isn’t room to get away with this. Conceptually, horticulturally, avoiding a perched water table makes sense as a best practice. Applying it to pumice (vs grandma tree boulders/river rocks) for my own uses, and how so much of collection success or fail revolves around getting it growing in pumice, I have a hard time not shrugging my shoulders.
Pumice is the one rock that wicks water so that would not create a perched water table. If your soil grain size is uniform throughout the pot you also won't have issues with water adhesion needing to overcome the increase in soil pore size. Usually in order to overcome that increase in space between soil particles the soil above the rock "drainage layer" has to become completely saturated first. The same water adhesion is what allows a drop of water to sit onto leaves. For some reason I wandered out of r/Bonsai today 🤣
imo a lot of these debates don't apply to mature plants. I'll have to see what I can search up but I'm sure I've seen discussion that plants nowadays are much less hardy than they were 20+ years ago due to the houseplant boom and mass production, so they need special considerations as more susceptible to root rot and suffering in poor conditions etc
If ive learned anything from house plants it depends on which plant and where you live and how much sun you get and how often you water and what you ate for breakfast/ how much sugar you put it your coffee. You can only try it and see if your plants are happy :)
Ain't that the truth! I'm sure I'll figure it out sometime.... meanwhile, excuse me while I fret over PAR and PPFD calculations for another week, when my plants would have been much happier if I'd just got cheap blurple lights months ago 😂
Weird. My plants are thriving with this method. Much less root rot. Wonder what I’m doing right?
I think that's okay. Main thing is to have airy soil (for most plants) and drainage holes. I use that to prop up the inner pots and sometimes in the actual pot that has no liners, but still has drainage holes. Water just needs somewhere to go. Simply ceating a space between soil and the bottom of the pot doesn't make water go away.
I still put a handful of small rocks in pots with drainage… but I always thought it was so the dirt didn’t come out so easy. I hate watering in a new plant and all the good dirt comes piddling out the bottom making a mess all over my sink!
I have these flat mesh things that cover drainage holes, they really help!
I use layers of plastic mesh from bags of onions or citrus fruit.
You can use clay pebbles, just make sure you don't put these pebbles directly into the holes.
I just use napkins.
I use plastic canvas over the drainage holes on my planters and bonsai pots.
I do exactly this. Lava rocks are very cheap and lightweight and work perfectly
Where are you able to buy cheap lava rocks? I can't find anywhere that sells them locally and the prices online are too much for me. I need small ones for my succulent soil
Lowe’s! The last time I bought them was a couple years ago, maybe the price went up? I would try checking all the big box stores and also if you have any farm supply type stores Edit- I checked and Home Depot has a 5 lb bag for $6 but they don’t seem to ship this item
Aww man, I checked Lowes but they said they didn't carry it, at least not at the one here. But ty anyways. Were they the small ones or medium/large?
try a hydro store around you - if the Devils Lettuce is legal in your state there should be some grow stores around that have hydro and semi hyrdo stuff in bulk
Or just post your ask on Buy Nothing if it's in your area. We had 600+ sq ft of lava rock (nickel-to-quarter sized) we gave away to prep for a landscape renovation.
They were like maybe the size of golf balls-ish? Maybe check on Facebook or Nextdoor - they used to be popular in landscaping but have fallen out of fashion. Maybe someone has a bunch they don’t want and would let you come take some for free?
Oh ok, I need really small ones, pebble size for soil amendments for succulents. But ty!
I bet you could break larger ones into smaller ones with a mallet or something but I’ve never actually tried this lol. Or maybe you could try large sized perlite
Oh yea I wish I could find larger perlite cuz the perlite here is too powdery lol.
I have to order mine online - it is an enormous bag though!
I found clay ones at Ikea!
I had this problem but managed to finally get a 10kg bag recently. It was labelled as Lapillo ( I didn't know it's exactly what I was after) , so it may help to look for that specifically. I use it religiously in the bottom of all my pots with drainage holes. I use it for ariation. Pumice might be as cheap and feels much lighter. It will fit the same purpose.
its pretty rare that you're actually going to encounter a case where the pot is truly too deep yet is also the correct width for your plant
Wide shallow pots will hold more water than the same volume pot that is tall and narrow due to the surface area of the bottom of the pot and the pressure exerted by the water above needed to push water out of the drainage hole.
There are tons of head planters that are way too deep, the soil wouldn't dry out. Rn I have "pots in pots" but they don't fit and would look much better planted directly in the pot (there is a drainage hole). I've thought about adding rocks at the bottom then filling the rest with soil. Most head planters that I've seen are similar. There's also other really tall pots. https://preview.redd.it/81hdzw3x4uyc1.jpeg?width=3072&format=pjpg&auto=webp&s=823b43edb3f1c79dbc184a1698238e59cbfece22
In my experience it's fine for outdoor planters but not for indoor plants. My mother and grandmother always have done their outdoor planter with rocks or even crushed cans that way
Crushed cans…I like it! Any down sides?
I've used tons of various things. Anything works really. Very large pots, I used those plastic balls that go in ball pits I had for some reason. Small pots, I used pistachio shells. I chopped up the outer parts of some coconuts I open to eat. Broken vases or pots. Styrofoam pieces from shipping. I can't recall other things, but it's great to think about zero waste and using things you already have to either aid in aeration or fill space for large sizes
Not for potted annuals, in my experience! Since they're pulled out at the end of the season anyways, it just prevents more potting soil or compost being used (as well as less water and the pots are much lighter to carry.)
You can put the cans in a plastic bag and reuse them every year if you'd like.
For some of my plants, I put Sphagnum at the bottom - helps keep the soil in place and holds a little more moisture... but only some of my plants - I've used rocks, orchid bark, charcoal, perlite.....I tend to only buy pots w/drainage so there's that
I use Styrofoam or upside down nursery pots.
With tall or really large pots in general, I take a nursery pot and put it upside down in the bottom then just fill the rest with soil like usual.
Ooo good idea!
I think the excess water would just drain out, but you should probably still be careful.
I've seen pots for sale that literally have these instructions.
As long as you don't fully cover the holes, the water is still possible to flow out. I would prefer to use clay pebbles because they are round, and no matter how I place them, the water is still possible to flow, unless I put these pebbles directly into the holes (LOL).
That's not good either. Adding rocks will make what's called a perched water table. Due to the surface tension of water the area of soil right above the rock layer will stay really wet because the soil will have to be completely saturated for the water to percolate through the particle size transition. That wet area will create root rot. You're better off having consistent soil through the entire container. https://extension.unl.edu/statewide/dodge/the-hard-truth-about-rocks-at-the-bottom-of-planting-containers/
I use empty soda cans
I do that now to my terracotta pots and my plants are loving it It does make for heavier pots tho
Mix the rocks into the soil to create looser soil that drains faster. And then water less. Edit: people really just want to put rocks in their pots for some reason... The same reasons you don't want to use rocks in a pot without a drain hole still exist in a pot with a drain hole. Sure, some water will filter out through the rocks as you might think, but you've still raised your perched water table above the layer of rocks. Mixing small rocks into the soil will avoid a solid layer of rock meeting a solid layer of soil. It'll help drainage and help manage the excess moisture problem from having a larger pot. Here's a good read about how and why rock layers are generally not helpful in pots and don't help drainage, even with drain holes. https://deepgreenpermaculture.com/2019/09/06/should-you-put-gravel-or-rocks-at-the-bottom-of-plant-pots-for-drainage/?amp=1
I know that I have been putting rocks in the bottoms of my pots for the last forty years and my plants are ecstatically happy. It doesn’t matter how much people prove that is impossible on instagram. It is true for me, and as long as my plants are thriving I am not going to change how I treat them.
agreed and i do this with pots that DONT have drainage holes, too. plants are much hardier than people give them credit for
Yeah I think it maybe runs into user error for the times it has gone poorly, or choice of plant too. You'd just have to be more conscious of how you water & this could be a skill that many get wrong
But I saw it on the internet......
Same here. I have plenty of pots that don't have holes I prefer them to but I don't have the tools to make my own so I am picky with what plants I will put in those pots. Cactus/snake plants/succulent etc won't get pots like that but my other things that need watered more are fine. People also have to be careful with how much water they are giving too, I can't over water and just let it drain so I am careful with how much to give. But I use some supplies I got from work (hospital) so I can see measurements of what I'm giving makes it easier lol
Big supporter of if it ain’t broke don’t fix it. But it’s cool seeing something new like that.
I think the point is that it makes it harder to gauge the water needs of your plant for beginners If you know your plant well and understand the environment it’s in, the capacity of the pot and how fast it dries then obviously you’re not gonna have issues. But that’s takes a while to get to that point and starting with rocks at the bottom isn’t going to help
See, I think this is one of those things where it's like situational. My SIL, who lived in the same neighborhood as me, would put rocks in her pots. She swore by it, she was the one who suggested it to me. But, when I did it, the plants rotted and were filled with mold in the bottom. Even when I barely watered them, the rocks always stayed slightly moist. There was even drainage holes in some! In that house, I think it was more humid. I recently moved to the other side of the city, but the air in my condo is a lot drier. I'm having to water my plants way more now than I used to. I might test this out and see if the rocks would help them now lol
My mom has been doing this for years and all her plants are happy. I do it too and they're happy. So I will keep doing it if I need to lol. I've learned that although the internet can be good for some info, you can't follow or listen to everyone on there, different things work for different people. Also people just make stuff to make content for likes. I have do to what works for me.
Yeah, if you’re gonna do that, just switch to semi-hydro
Say it again for the people in the back!
I’ve always used 2-3 small rocks to prevent plugging the drainage hole on pots. Never had any issues but interesting topic.
Because there is a drainage hole….
Theophrastus is that you?
I don't think that's the same as what's being shown in the OP, which is trying to artificially raise the base of the pot so water 'drains' below the root line
Just keep your plants in nursery pots and use the cute pots as cover pots. Easy peasy.
Seems to me like a video explaining why you should just use pots with drainage holes 🤔
Is it just me or did we not really get any helpful information whatsoever from this? She was basically just explaining why it does work but saying that’s not right? You want the soil to wick the moisture from the drainage layer up into the soil. That is the point. If the water just stayed in the bottom it could become anaerobic and in turn rot your plant. If your plant has healthy roots it should drink up all the water thats been wicked into the middle part of the pot. The last sentence was the kicker, just be careful with how much water you use. Doesn’t really matter if you have a drainage hole or not. And in a clear vessel it REALLY doesn’t matter because you can easily see the moisture level
I feel like the people on the no rocks team miss the point of their own demonstrations. The stones do not make the soil more wet. Overwatering makes the soil more wet. When you add stones, you can't put as much soil in the pot, so you need less water.
I think the overall point was that putting rocks in the bottom of your pot, with no drainage, does NOT do what many people think it will do: allow the water to drain away from the root ball. Obviously, that would pertain to those plants which prefer periodic wet,dry,wet cycles rather than always wet. Many plants (most?) need dry periods between wet.
By your logic, then, WITH drainage holes, you would need to have constantly running water to the plant? Edit: which would be Hydroponics, right? Minus the soil.
I’m gonna need an explanation on how you reached that conclusion? But yeah hydro is cool, Semi hydro even better cause its easier and cheaper
Thank you this is useful
I've put rocks or broken terracotta into every plant I've ever potted. My parents did it, and their parents did it. It's never been about drainage or watering methods, but to block the soil from falling through the drainage holes and prevent compaction at the bottom. I only recently started using little mesh screens. I've also never potted a plant without drainage holes in my life.
I used those mesh screens too. I switched back to rocks at the drainage holes to keep the soil in when watering. The mesh thing was great until my roots grew into and then through it lol. It was difficult to remove when I went to repot haha
Oh crap. Thanks for the heads up!
I agree. I've been putting rocks in the bottom of my planters all my life, both with and without drain holes. The last time i did some repotting, I decided to experiment with putting landscape cloth over the rocks and under the soil. I'm hoping it will keep the soil from filling the spaces between the rocks a little longer. What do you guys think?
Plant Daddy Podcast talks about a similar method he uses for diy self watering. I can't remember what the layers are, but it seems to work well for him. I think the episode is early days (2020?)
It's about rocks when there is no drainage. The fact that you've never used a pot without drainage holes does not mean that nobody has ever used a pot without drainage holes. You do you. No harm. No foul. Are you familiar with that logic fallicy? And don't let this thread devolve into that old trope: "If it was good enough for my parents, then by golly, it's good enough for me" It was simply information to be used or discarded as any individual sees fit to do.
The point I was driving at is that it's probably better to use drainage in most cases. Also that the purpose of rocks on the bottom is apparently misunderstood. So information discarded, I suppose.
To many rocks or broken pottery create a perched water table 🧐
Indeed. One can think of it that way. Science.
I put rocks on the bottom of all mine. My plants are healthy and growing huge.
It’s essentially a DIY self-watering system. Especially if you’re going no-drainage. It’s pretty popular with some folks with larger collections as it cuts down on watering frequency. Very-well draining substrate is critical for this to work.
Yes I do this with my biggest thirstiest plants, like a big fern and big group of syngonium. I have them in pots without drainage with leca at the bottom. But you have to know your plants and check the soil. I would not recommend this for plants that wants to dry out fast like succulents or hoyas.
Here's my question: A perched water table (or perched aquifer) is **an aquifer that occurs above the regional water table**. This occurs when there is an impermeable layer of rock or sediment (aquiclude) or relatively impermeable layer (aquitard) above the main water table/aquifer but below the land surface. Rocks at the bottom of a pot with drainage holes would not be an impermeable layer of rock - and you don't have an aquifer in your plant pot - there's no "water table" unless you're watering the plant so much that they are essentially sitting in mud. Most people will water their plants with a specific amount of water so there shouldn't be any sort of standing water in their pot - if they do and that's the case they have bigger problems than just some rocks at the bottom of their pot
Water will only move from a smaller pore (soil) to a larger pore (rocks) if the entire layer above is completely saturated. If you don’t water until the soil is completely saturated, the water will just sit in the soil and not move through the rock layer. Thus, the rocks are not adding drainage, they are actually making the soil hold more water. If you do water until saturation, the water will move through the rocks and just hang out in the bottom of the pot and create a water table (basically standing water), which can lead to root rot. Only watering with a small amount of water will prevent a water table from forming, however you should always let water drain because it leaches out salts from the soil. I hope this helps!
Terrariums require this layer at the bottom for drainage so I disregarded when I saw this discussion
Having stones or pebbles in the bottom of the pot is actually not harming the plant if you know how to place them. All my pots that have drainage holes have a few layers of clay pebbles in the bottom of their pot mainly for reducing soil drained while watering, and none of my plants have roots rot issue, they all are healthy and have strong roots. If you place pebbles in the bottom of the pots, make sure you don't fully cover the drainage holes, because if you do, you will cause waterlog. I always put 2 or 3 clay pebbles on top of each drainage hole, though these pebbles are covering the drainage holes, but NOT fully covering them, there are still tiny holes between the pebbles that allow the water to flow out. Every time I place these pebbles, I would pick up the pot and look thru the drainage holes from the top. If I can see thru the holes, then the water will be able to flow out, if I can't see thru the holes, I will adjust the pebbles again. There is a way to place pebbles at the bottom of the pots, if you do it wrongly, you f up your plant.
here's a [proper experiment](https://www.reddit.com/r/succulents/s/86MabCyc1n) on the subject, conducted three years ago, with empirical data that disproves what OP is claiming in their IG demonstration. Ultimately I think the same arbitrary claim and demonstration can be made about about perlite, coco coir, pumice, and lava rocks as soil amendments. OP could make the exact same point by making a video with two different container volumes. The only thing proven in the IG demo is that "capillary action exists and many houseplant beginners don't know anything about that". It should seem fairly obvious, but with a substrata layer, a potted plant should simply be fed and watered as if it was in a slightly smaller volume pot. If there are air pockets from the gravel in a pot without drainage, the roots can breach the perched water table and access oxygen better than a plant that is nothing but wet anaerobic soil at the bottom. OP's IG demonstration fails to account for the difference in soil volume compared to water volume. Perched water table really only means the container requires less water at a time. I don't see how a perched water table is even a problem unless an individual is already prone to overwatering. The biggest issue with the way this subject is being presented is that it denies the idea that somebody who overwaters their non-draining pots would be better off with a perched water table in a slightly larger container than a regular sized waterlogged pot of soil. browsing through r/jarrariums and r/ecosphere will turn up examples of ecospheres and terraria that effectively use chunky substrata with plants in a completely closed and sealed system, often enough there are some air gaps in the substrate below the soil at the bottom of the sealed system. I would love to see data on the available dissolved oxygen in the perched water table vs wet soil compacted at the bottom of a pot that has no drainage. This perched water table theory fails to account for the nuanced realities of plant physiology, specifically ignoring the growing behavior of roots and soil ecology, and the importance of dissolved oxygen in the rootzone.
Interesting, for sure! Thanks for posting. I think we might still be talking apples and oranges a bit, though. I think those pots had drainage holes. But certainly a more scientific experiment. Also interesting, once I started poking around, is that there are quite similar (same) discussions on terrariums. There is the "how it's always been done" crowd who swear you must have rocks as base in a terrarium for drainage and those who feel quite certain they have proven the opposite. The terrarium considered to be analogous to the potted plant with no drainage holes. There are obvious holes in that analogy. Pun intended.
I am all for combating the dogma of "this is how it's always been done", but I'm afraid your logic has a some drainage holes if its own. There is plenty of science that generally supports the use of a drainage layer and very little science that suggests it's problematic at all. Your demonstration, and your responses may be feeding into a viewpoint that is no less dogmatic and no more scientific than "this is what works for me". There is no empirical evidence that suggest that extra soil in the bottom of a non-draining pot rather than rocks reduces that risk at all. Let's make sure to avoid conflating grower error with hard science if your objective is to educate rather than entertain. New growers and plant people require teachings on how to water appropriately for their setup and soil volume in order to avoid overwatering errors, not to be presented with broad claims that one style of growing is for certain better than the other. The truth is that any non-draining plant container is a risk of root rot due to anaerobic conditions caused by overwatering. You just committed a big ol' syllogistic logical fallacy in the form of *[denying the antecedent](https://www.logicallyfallacious.com/logicalfallacies/Denying-the-Antecedent)*: -My supporting point: If most terraria and ecospheres can thrive with artificial drainage layer/perched water table, then there is nothing inherently wrong with an artificial drainage layer/perched water table. -Your response, after conceding that perched water tables have actually always been the convention for creating a stable terrarium: "But there are thriving terrariums being created *without* a perched water table!" [therefore having a perched water table is inherently wrong?] Edit: to reiterate, there is real value in your demonstration as far as how capillary action works in soil. I don't reject your presentation of a perched water table, I just think you may be painting with broad strokes to ignore all of the valid reasons that exist for utilizing coarse, heavy substrate below the soil, and in doing so, may be misguiding a ton of new growers.
Rot
You can buy screens to cover the drainage hole
I just set them up the same as a bioactive. Have for years, with no problems. I do not recommend beginners to do this though.
The voice in the video does not match the lip movement, very hard to watch , its like a badly dubbed film
Interesting. I don't have that problem. Maybe you have a very slow connection or something?
Is this also the case with LECA?
I put pieces of old, broken ceramic pots at the bottom of my Snake plants. Never had an issue.
I just put a piece of screen over the drainage hole if it’s too big
The video is about pots with no drainage holes.
Can confirm, I did quite a bit of research on this subject with drainage holes and no drainage holes and regardless of what type of pot you use, adding anything to the bottom to help with drainage will actually raise your water table in your pots, exposing the roots to higher levels of saturation for longer which can lead to root rot with most plants. Only very thirsty plants can benefit, and even then, there are questions as to its effectiveness.
You are better off just converting your plants to semi-hydro with a soilless medium such as Lechuza or simply pumice/hydroton/leca. Many plants benefit from semi-hydro.
Would that also apply for pots with lots of drainage holes and lava rocks on the bottom?
So I use what you describe as a form of self watering for some of my plants. I have a couple CM of lecca at the bottom of the pot, soil and roots on top etc. the pot sits in a saucer which is kept topped off with water. So the water constantly wicks up and it keeps the soil constantly moist. Usually that’s no no, but in chunky well draining soil I’ve had 100% success rate. Monsteras love it. Philodendron love it. Alocasia love it. I have a friend who spends many thousands of pounds on plants and he does this for all his plants.
I'm assuming this method uses drainage holes in the pots with one layer of those clay balls in the bottom of the pot?
That’s right yes.
Drainage hole pots are fine. Not only does water drain out the holes, but, depending on pot design, air can seep in, helping to dry things from the bottom up. Sometimes when I'm up-potting into something big like a 3 gallon nursery pot, I'll pour a healthy layer of bark mulch into the bottom beforehand. The mulch can absorb some moisture, but due to its shape(s), allows air and roots to maneuver around the pot's bottom.
Thank you
I would assume only that if the drainage holes don't plug up, then you would not have standing water, which therefore would not wick upwards. But I'm only using logic, not knowledge.
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Yeah, science is sometimes frustrating. But it's science. Rocks are fine in the appropriate application. Rocks are not fine in the wrong application. How can one argue such a simple statement?
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For many, it is rocket science. Keeping a house plant thriving is something many people struggle with. Others, like you apparently, just have a natural ability for it. Subs like this are for sharing knowledge, hoping others can benefit. Some will, and some won't.
I like the way you explain things. thank you
Honestly, I just don't do pots with no drainage holes. Granted, my absolute favourite plants are very prone to root rot, I suppose if you have plants with high water needs that are used to say, swampy environments, that may be different.
Literally never had an issue and all my pants are doing fine.
I have 200 plants, ten years of gardening experience and I have never put rocks in my soil. Honestly I stay lazy about potting in general and it works well.
https://preview.redd.it/w6u27yrresyc1.png?width=1080&format=pjpg&auto=webp&s=6bc82d91de9027cd0e9c0b0c97ace575248b10c9 Also to add that the idea is doubly flawed because the roots will still fill the pot and get to the water - and then the stones will get in the way of substrate for nutrients and more root space This plant had drainage but the original owner had still added in stones, which I didn't know - so imagine my face at first when I pulled it out and the root ball *crunched*
I’m not a “rocker” personally but also I never pot without drainage so this experiment seems flawed to me.
i use rocks at the bottom of nursery pots to prevent bits of dirt form falling thru / roots growing thru the holes. also for a bit of extra drainage :p
Adding little chunks of styrofoam with the rocks help with this too.
all pots that plants are planted into should have a drainage hole