Diagnosis Required

I am a newbie - very little knowledge.
I noticed my potted plants getting some yellow leaves which I assumed was fairly normal.
The plants are almost human height, in 15-20L pots.
The yellowing seems to be more prominent now, and the plants are in the early stages of flowering. 2-3months left before the usual NSW, Australia harvest.
The leaves at the top are certainly greener than the leaves at the bottom.

I have been regularly feeding them Seasol while in the growing stage. Once per week with 2l of water (from adolescent onward until now) that is, 2l per week since they were getting large, about 1.5 ft. I understand a smaller amount is better more frequently, but they do not live in my backyard.

Only just recently I decided to give them a higher potassium drink (searles postash), with no nitrogen, as per my limted research for the flowering stage.

Leaves have decided to go further yellow with some burning and white spots also. I don't believe the white spots are fungas or mould as they are very clean.

I thought perhaps over watering or nitrogen deficiency but I'm not sure.


.. any suggestions regarding the illness ?

Thx in advance

Looks like N deficiency. All your leaves look pretty light. How heavy were you feeding in veg?

Hey thx for the reply .. I've used this product during veg, about 2/3rd of a capful per 2L container, roughly once a week. Sometimes closer to every 5 days.
It's a well regarded product in Australia derived from Seaweed.

It has been raining intermittently. Quite a cloudy and damp summer, with hot days in between. The plants are getting about 60-70% full daylight. I just checked the pots and revealed the soil under the mulch layer, which was not overly damp at all.

I should also suggest, as a photographer, I understand colour problems with cameras etc.. This HTC phone gives overly warm images. The leaves aren't quite as yellow as in the picture. Nonetheless, certainly not the correct weed green.

Looks like the potash burned them...

potash was only fed once, and to the suggested amount diluted into 10L of water. I guess it's possible, .. ?!

Just checked my phone camera, it was set to +.05 EV. So all the pics are actually lighter and more yellow than actual..

They look hungry. when plants start to flower they grow like a motherfucker so they need nitrogen for at least the first few weeks. I cant see the npk on your bottle but it sounds more like an additive than a base fertilizer.

You might be onto something there .. ! N 0.1%: P 0.01%: K 1.8%.
"Seasol contains only very minor quantities of Nitrogen, Phosphorous and Potassium Weight to Volume N 0.1%: P 0.01%: K 1.8%. It is not, by definition, a fertiliser (as it contains only marginal nitrogen and phosphorus levels). Seasol seaweed concentrate is a complete garden health treatment that contains plant nutrients, trace elements, alginic acid and other bioactive compounds"
So given the plants are definitely into the flowering stage, should I give them a hit of nitrogen now ?

Yes you should stay on the N til about week 4 flower. It wouldn't hurt to add some Epsom salt for magnesium all so at 1tsp or 8 grams a litter. I know your guys teaspoon measurements are jacked up over there.

yeah I would. If that's all you've been using is seasol you need a fertilizer that contains all three macronutrients. Dyna gro foliage pro is a good base nutrient if you can get it where you are. Its cheap, one bottle, and can be used from start to finish by itself.

KryptoBud said:

They look hungry. when plants start to flower they grow like a motherfucker so they need nitrogen for at least the first few weeks. I cant see the npk on your bottle but it sounds more like an additive than a base fertilizer.

Click to expand...

what he said