Hey, I have 4 plants, the oldest one is having problems. It's leaves are turning yellow, starting with the bottom leaves, and progressing upwards. The yellow leaves also dry up and have some dark spots on them. I'm guessing this is fert burn? The plants growth itself hasn't slowed, it's actually growing faster than ever. Already the oldest leaves on the plant have dried up beyond repair, they are definitly dead, about 4/5 of the plants leaves are still doing great, I've actually seen growth of leaves branching off the stem next the already effective leaves. Do you think I should flush? To try to get some of the excess build-up of possibly ferts out of my soil? I also have slow release ferts in my soil, but they are a SUPER SMALL dosage which shouldn't harm the plants. So would flushing help?
it could be fert burn, but that mostly effects the tips of the leaves, yellowing in an even tone starting from bottom could means nute deficancy or nute lock up wich could be caused by your pre ferted soil
I haven't given them enough ferts that I would think could cause this damage. The plant is about 6 weeks old and has had 2-3 fert feedings that were at something like 1/6 normal dose. Also, I haven't fed this plant ferts in about 1 1/2 weeks, and this problem just started maybe 5-6 days ago, so I don't THINK it's from the ferts I've added. Nute lock-up sounds like a strong possiblity... Any way to make sure this is the problem? And how does one solve this type of problem? All help is greatly appreciated.
One it could be that soil. It could be lots of things. The problem is with most pre fert soil is that its water activated so flushing just releases more ferts. It could be that maybe these plants are growing at a rate now that it is juat a def. and its time to feed. Or its locked up and cant feed. I foyu did not have that soil then I would say its time to up the dose, thes plants need food. But that pre ferted soil raises the ? is it lockout? and if it is I think your screwed. I do not know much about pre fert soil. Maybe it is possible to just flush it out. Then see if the plants recover. If it gets worse after fulshing then maybe it does need to be feed. But then again here come your soil prob maybe flushing just released more ferts and is damaging the plants more. Gee one thats quite the pickle. You see why we told you to avoid that soil, repot. Just move them outside now, your attic has got ot be getting hot.
My grow room has been keeping 85-90F during the day and about 75F maybe a little cooler at night. I've got a new venting setup that lowered the temps and is keeping the room full with fresh air. Thanks for your help 420, but if anyone has more experience with slow release ferts in soil, it would help alot... I am worried that flushing would just release alot more of the ferts in the soil, that's why I haven't done it yet, and other than that, would the plants leaves really turn this yellow and die off from not enough ferts? If thats the problem i should try giving the plant some ferts? Unless I hear otherwise I will give the plant ferts next time I water. Thanks everyone, more help would be appreciated.
lack of N is what would cause the leaves to yellow and die usually. 2 things could be happening. Theres no nutes so the new leaf gorwth is taking the nutes from the old leaves to grow and will sooner or later run out and die, or the soil is locked and the roots cant absorb nutes so the new leaf gorwth is taking the nutes from the old leaves to grow and will sooner or later run out and die.
Solo is right. Flushing rids the roots of excess salts that have built up around the roots so it may be a good thing to try first. That way you can at least narrow the problem down.
Check your pH. Yellow leaves are usually overwatering but the dark spots will become necrotic later. My guess is your pH is a bit to the akaline side. Cannabis is an "acid lover"
