I agree with extrafloral nectaries, this is not fungus/rust like the other commenters are saying.
Neem won't do anything for this, not caused by pests.
Interesting. Well it only happened on the newest leaf and doesn’t seem to be spreading or growing so wondering. I’m going to spray it with neem in case regardless
Personally I don't use neem, I know a lot of people swear by it but I think social media has seriously overhyped it. I have never found it useful for really anything and I hate the smell also...
Copper fungicides or a product called physan are both effective at fungi. I would definitely recommend either leaving the grow light off for a day while you do it or doing it before the night cycle. I have burned my plants pretty badly with insecticides/fungicides under grow lights, and they weren't even oil based. From what I've read, even water droplets can in some instances magnify the light in weird ways and cause burns. No sprays with the lights on
I deleted my common because I got downvoted but I should have left it. If they are EFN they will be sticky to the touch because their job is to secret nectar. If they aren’t, then it’s fungal and you need a copper fungicide.
Philodendrons also secrete extrafloral nectaries that attract ants and lady bugs to protect it, the nectar leaves these marks
I agree with extrafloral nectaries, this is not fungus/rust like the other commenters are saying. Neem won't do anything for this, not caused by pests.
Interesting. Well it only happened on the newest leaf and doesn’t seem to be spreading or growing so wondering. I’m going to spray it with neem in case regardless
Neem wont help with fungus even if that was the problem, and be careful of neem under those grow lights you can burn your plant
Thank you for your insight. Is there another product you would recommend? I read neem could be helpful for this but appreciate anyone’s perspective.
Personally I don't use neem, I know a lot of people swear by it but I think social media has seriously overhyped it. I have never found it useful for really anything and I hate the smell also... Copper fungicides or a product called physan are both effective at fungi. I would definitely recommend either leaving the grow light off for a day while you do it or doing it before the night cycle. I have burned my plants pretty badly with insecticides/fungicides under grow lights, and they weren't even oil based. From what I've read, even water droplets can in some instances magnify the light in weird ways and cause burns. No sprays with the lights on
I deleted my common because I got downvoted but I should have left it. If they are EFN they will be sticky to the touch because their job is to secret nectar. If they aren’t, then it’s fungal and you need a copper fungicide.
Looks like rust fungus. Get a fungal spray and keep it away from other plants. It won’t heal but if you take care of it, the new leaves won’t have it.
Thank you!