23 Days, Yellowing Fan Leaves

For the last week, especially the last few days, I've noticed more yellowing leaves on my Blue Cheese. Ever since I got the clone at 7" tall it's always had some issues with a couple leaves being yellow or really light green at any given time, but it never really got any worse than that until about a week ago. Now it seems like it's taking over all the fan leaves. It's not concentrated in any specific area, there are yellowing leaves throughout the plant. The flowers are looking good and new growth of hairs, buds, and smaller leaves still and seems to be continuing to develop really well.

Some additional info... I repotted the plant from a 1 to a 3 gallon about a week before putting it to flower. I only had regular Miracle Grow at the time so I didn't give it any nutes for 3 weeks. Then on day 14 of flower I gave it half strength Jack's Blossom Booster (1/8 tsp per gal). I also did a good amount of LST that day that could very well have injured some leaves. The next watering was yesterday when I gave it full strength Jack's Blossom Booster. Most of the yellowing seen in the pics was already happening by then and I was hoping nutes would help since my other blue cheese mom in veg has been neglected and started getting similar issues with the leaves.

I've researched all day and I've read that it's normal in flowering (seems early to me though), it's nute deficiency, it's nute burn, etc. Idk, it's my first grow so it's really hard to figure it out. Hopefully some pics will help.

First 2 pics are on Day 20 when there was just a bit of yellowing starting. Unfortunately these two pics were taken right after I removed most of the really yellow leaves. The rest of the pics are from today, Day 23.

looks like a nitrogen deficiency to me. whats your ppm and ph?

i disagree, nitrogen def usually starts at the bottom and moves up, and during flowering, you dont need much nitrogen. i say iron, sodium or sulfur deficiency.

Hard to tell from the pics, is there a dark(er) green vein, in those yellow leaves ---> if so---> iron deficiency
Sodium is lacking when theres upper yellow leaves, but its one of those trace elements, a lil boosts yields, too much is toxic.
Sulfur ---> this could be a progressing sign of sulfer deficiency, but its hard to tell, sulfur youll know 100% if they continue to turn whiter whiter (end stages of sulfur def).

Quick and easy fix: get a WEAK soup of different stuff, with a variety of trace elements and use that.

what kind of water are you using? and nick17gar if you look at the fan leaves its yellowing from the bottom, ergo the element that is missing is mobile. so the mobile nutrients are either N, P, K, or MG. chances are in flowering, you cut down on nitrogen and your leaves are bound to turn yellow. IMO go for the common deficiencies. I am growing a round of blue cheese right now actually. I find that they like their PPM under 1000 and with a ratio of 1-2-2. psyte is also growing in soil, sulfur deficiency is like a once in a lifetime occurrence but could happen if you reuse your soil

Cool thanks guys. I'm watering with tap that has sat out for at least 24 hrs. Mixing w/ Jack's Classic Blossom Booster which is 10-30-20 and contains trace elements. I just started introducing the nutes the last couple waterings (didn't want to do it any earlier because I wasn't sure how long the nutes in the Miracle Grow would last and I didn't want to burn it).
As far as PPMs, I'm not sure. I only have basic equipment right now.
The leaves have started yellowing all over the plant more rapidly in the last few days, and it's hard to say if it really evenly progressed from bottom to top, but the yellowing has always been a bit worse at the bottom. Part of the problem is I have to turn off the HPS and turn on a light more in the blue spectrum to really see the yellowing very well, so it progressed to this point within a few days without me really noticing exactly how it progressed. I am keeping a better eye on it now though.
The leaves are yellowing fairly evenly, but the veins are a bit darker. The plant in general has become a bit lighter green.
Definitely don't reuse soil.

I think you at least both agree the plants aren't burned, but that it's a deficiency, so at least I know I should keep going with the feedings.
I'll see if I can snap closer pics right before the HPS comes on this morning.

psyte, i think your problem is that you use tap water. tap water is often hard water and contains too much calcium. PH for tap water can go higher than 7.6 if you live where i live. your plants want a ph of around 6.5 if your in soil. you need to get a PH tester (either a PH meter/ or a testing kit).

I'll see if I can grab something to test my water's pH today.

I live in michigan too, so that may be the case.

haha well i am from indiana and our water is hard as shit. i had to use RO water filters for all my nutrients. if your on a budget man, get the PH testing kit from General Hydroponics. its less than $20 bucks and its always accurate.

beautiful plant....shame , but me being new....it does look like some defiency.....idk tho. the ppl. hear give sound advice= it will come back.

Okay, so here's some new pics taken closer up this morning. There was some leaf curl before but it looks like that's progressing also. Mostly from the middle of the plant down, not too much curl towards the top.
Also, take a look at the other plant in the last pic. This is some bag seed I started a week or so before I got the blue cheese clone. It's on day 15 of flower and looking very healthy; it's looked great the entire grow and has had zero issues. It's been treated very similar to the blue cheese in regard to soil type, water, and very similar in nutes (just a bit behind the blue cheese since it was put to flower nearly a week and a half later). I guess either that bag seed is very tolerant or the blue cheese is a finicky bitch. haha.

Off to the store to get the pH kit.

Nitrogen deficient. Probably could use a little additional Magnesium also to compliment your tap water. Blue Cheese is a heavy feeder.....

to my expirence blue cheese is a little bitch to grow. i ran it on the same aeroponic system as my other strains, it got spotted and burnt after 1000PPM. LOL. so i ended up taking it out and putting it into another system... but yeah watchhowidoit is more than likely correct, most problem during flowering is nitrogen or magnesium related issue. most people stop feeding plants N during flowering. Magnesium uptake is increased in flowering too, especially if u got like hard water, your MG uptake is limited. If your using RO/ Distilled water, you need to supplement with calcium and mg

but anyways, i say you go full strength on your fertilizer. i always go full strength, maybe that will help with the yellowing. My NPK ratio during 4th week of flowering is 40-64-56 + additives, havent had any yellowing yet

Cool... yeah I've been looking through some Blue Cheese grow journals and it looks like it really can be a pain in the ass. Great choice on my part for first grow, haha. Better be some damn good smoke... if I don't fuck it up, that is.

So anyhow, I got the general hydroponics test kit. It's hard to tell by the color strips, especially since they don't show anything between 7.0 and 8.0, but it looks like I'm somewhere in between those two. So you were dead on, urgod. I'll stay with the full strength on nutes. I'm assuming fertilizer will affect the water pH, so I'll measure again next time I mix up some water and adjust from there.

I really appreciate all the feedback. I was leaning toward deficiency but there's so much conflicting info out there and I didn't want to end up making this worse.

nick17gar said:

i disagree, nitrogen def usually starts at the bottom and moves up, and during flowering, you dont need much nitrogen. i say iron, sodium or sulfur deficiency.

Hard to tell from the pics, is there a dark(er) green vein, in those yellow leaves ---> if so---> iron deficiency
Sodium is lacking when theres upper yellow leaves, but its one of those trace elements, a lil boosts yields, too much is toxic.
Sulfur ---> this could be a progressing sign of sulfer deficiency, but its hard to tell, sulfur youll know 100% if they continue to turn whiter whiter (end stages of sulfur def).

Quick and easy fix: get a WEAK soup of different stuff, with a variety of trace elements and use that.

Click to expand...

I concur, "Bills Perfect Spray and Grow" works well for that, or just get a micronutrient supplement.

yep micro would work if it has nitrogen in it. I use GH micro and its great. when your using your GH ph tester aim for a yellow color that is generally around the 6.0 range

This is the analysis for the bloom fertilizer I recently started the plant on (Jack's Blossom Booster 10-30-20) from the manufacturer's website:

Total Nitrogen (N) 10%
5% Ammoniacal Nitrogen
5% Nitrate Nitrogen
Available Phosphate (P2O5) 30%
Soluble Potash (K2O) 20%
Magnesium (Mg) 0.50%
0.50% Water Soluble Magnesium (Mg)
Boron (B) 0.02%
Copper (Cu) 0.05%
0.05% Chelated Copper (Cu)
Iron (Fe) 0.10%
0.10% Chelated Iron (Fe)
Manganese (Mn) 0.05%
0.05% Chelated Manganese (Mn)
Molybdenum (Mo) 0.0009%
Zinc (Zn) 0.05%
0.05% Chelated Zinc (Zn)

its not N deficient...hit her with some cal/mag plus, and molasses both added to your next feeding.

IMO it could go one of 2 ways...either cal/mag plus and molasses fixes the problem, in which case it was a calcium or magnesium...or iron deficiency, or the problem progresses with dying and necrotic patches on the leaves...if that happens it is boron deficient, and some boric acid will fix it then...1 tsp. per gallon. it is basically eye wash. dont get the stuff for contacts, because it has all kinds of additives for eyes that the plant wont use.