GSC Auto - Brown Spots, Curling, Yellowing etc

Hey All,

Fed plants extra potassium for the first time and they are looking sad :cry:. They underwent a bit of heat stress through a heatwave we had about 2 weeks ago so some leaves have canoed but since then I’ve tried feeding 1/2 dose of potassium ash they’re beginning to flower and they seem to just be getting worse faster. The new growth droops and turns white at the tips then yellow and then brown whilst curling up. They are also a limey green colour rather than deep green. There is brown spotting on some leaves and they are curling upwards.

I thought it was excess potassium and have since flushed and even transplanted into a bigger pot as they were a bit large for their current ones and thought the nutes would spread out through the soil. This was about 4 days ago.

Growing in Canna Terra pro under a 100W LED board and 2x 75W CFL’s. Humidity has been kept at 55-60%, leaf temps at 23 (bar heatwave 35+) and watered every 3 or so days whenever it’s dry to my first knuckle. Please help me I can’t kill another one!




Kinda hard to tell what the heat and extra potassium did and what was pre-existing. If you already flushed, I’d just get them on a feed schedule for what ever nutes you are using and calmag next watering. Dont think it says how much water every 3 days but could be over watering too.

Yeah I was thinking watering , second knuckle is a little early I try to wait until it drys completely out. I notice the bit of droop then I water. As far as nutrients and heat that’s a headache. I have been there the problem is in the heat they drink more and take in more nutes as a result. So you can end up with nutrient burn without excess nutes and it takes several days to see any effect of nutrient changes so it’s easy to over do it. Best advice wait a few days and reacess. My disaster with that issue. I had to flush and get my temp In line.

1 Like