Yellowing leaves?

First grow! Blueberry Autoflower ILGM. Can anyone tell me why my leaves are turning yellow around week 8?

-Water every other day 1L
-feed once a week fox farm trio and added in cal mag once a week
-ph is 6.2
-40%humidity @80 degrees
-mars hydro 1000 @ 10” from canopy

1 Like

I am not sure what is going on but a couple things look off.
The lower parts are dark green & waxy almost like nitrogen toxicity However this is not showing in top. It looks like some kind of white powder on the bottom leaves? The yellowing of the upper leaves leads me to think it might be light burn. Even though it is only 150w at 100%, 10" is awfully close.

Also, do you check runoff pH & ppm? What are you growing in? Have you flushed according to the trio’s feed schedule? If not, this may be leading to other issues I see mid to lower parts of the plant.

2 Likes

This is my first try ever so I’m unsure on a lot. I did have nitrogen problems early in and I have no idea of the white powder, I’ll have to look. I thought the light might be close as well, so I’m going to move it up to about 14”, do you think that would be the best distance? Light distances have been somewhat difficult for me.

I have not checked ppm or run off. I used 70% miracle grow organics, 15% perlite and 15% peat moss in a 5gal pot. I need to flush today but like I said this is my first go at it and kind of not sure how or what to do.

Anything help or suggestions would be greatly appreciated.

Thanks

1 Like

Welcome to the forum. Everyone here is awesome about sharing their expertise and knowledge, I’m sure your issues will get corrected. I’m a new grower myself but I have been trying to stay away from the Miracle Grow soils just because of the added fertilizers they use so you may want to be extra cautious when applying additional fertilizers… I have burned so plants already this way. Good luck with your grow. Your in the right place :+1:

1 Like

Miracle Grow and cannabis don’t always get along. We see a lot of growers with nute burn from using MG, though some growers get lucky and get away with it.

The plant is a bit of a puzzle. The lower leaves look on the verge of nitrogen toxicity while the upper leaves look deficient.

It’s too close to harvest for a transplant, but measuring pH and PPM can give you an idea of what is going on in the soil and help you finish her up as best you can. I’d expect to see problems with both pH and PPM since you are in MG.

3 Likes

I just want to point out the significant difference in PPFD readings at various heights.


At 12" the center PPFD readings are over 1000. That is very high and can / will burn plants. The 16 to 18" height is a much better height with higher PPFD readings at the perimeter (i.e. consistent coverage).
What makes miracle-gro tough to grow in is the amount and type of fertilizer it contains. Then, if you add your own it can lead to burn and ph issues.
Do your flush and see what the runoff numbers are. At this point I would put Grow Big away and only use Big Bloom and Tiger Bloom. Big bloom is pretty harmless with its low dose NPK but has other good stuff. Tiger bloom provides what the plant needs to produce better buds.
Next grow look into LST to help manage plant height to achieve more even light distribution over the entire plant. Also find some happy frog or ocean forest mixes.
I think with doing the flush, increasing light height and monitoring nutrient intake, you should finish this grow in good shape. Good luck

2 Likes

I try to run my girls >1000 PPFD when in flowering. I run 3 HLG 135 panels above each flowering plant.

1 Like

Okay makes sense and will do. Also I have only been using big bloom and tiger bloom since week 5 at 1.5ml per liter of both and 1ml of ff bushwhacker once a week, should I have done more? I did lst but slacked a little on the main cola due to being nervous. I actually literally just ordered ff ocean forest hahaha thanks so much for the help, I really do appreciate it @beardless

I was trying to emphasize even light spread vs a flame thrower in the center. I run a HLG 260 over a 2x2 at 18 - 20" which puts me right around 1000 in the center and 600-700 at the edges

2 Likes

True that!

2 Likes

So I did the flush and first readings were 1200 ppm at 5.2ph. After flushing completely I got it to 500ppm and 6.4ph, Yall were right. Also did a little deflo on the lower section, now praying for the best. Forgot to mention before that I am running 24hrs light, just wanted to add that in.
Thanks for all the advice @beardless @MidwestGuy @Grow5150

2 Likes

Good. 1200 ppm isn’t too crazy but 5.2 is a bit out of range. Now on to harvest. The blueberry autos I grew took 90 - 100+ days. Good luck the rest of the way

1 Like