Yellowing leaves on young plants

The larger plants are about 3 weeks and 2 days old while the shorter ones are about 2 weeks and 2 days old. As you can see, the lower leaves of the larger plants are yellow and the middle leaves are yellow-green. The yellowing started from the bottom and is slowly working its way up. The top leaves are still pretty green but show a little bit of yellowing. Also, the stems are a little red.

I have a 400 watt high intensity light about 2 feet from the top of the plants.
I'm not sure about the temp but it doesnt get above 85 degrees. The humidity is low(utah). The yellowing started about a week ago and so 2 days ago I added some worm castings to the top of the soil and worked it into the soil a bit with my thumbs(using plastic gloves). I keep the door of the closet open for most of the time that the light is on and a few minutes ago i turned on a fan because i think it could use some more air circulation. About the time the lower leaves started turning yellow all of the plants pretty much stopped growing. I'm guessing its nitrogen deficiency, but the temp and/or air circulation has to have something to do with it because they all stopped growing at about the same time.

The soil is 7 parts Gardeners Gold which contains:
fir bark fines, forest humus, peat moss, pearlite, composted chicken manure, worm castings, bat guano, kelp meal, oyster shells, and dolomite lime.

And 1 part earthworm castings. Should i give it some chemical fertilizer on the next watering (tomorrow)? I'm not sure what to do.

I forgot to attach the pictures. Here they are.

I too would like to know the answer to that colour leaf.

Any help? Any experienced growers out there that know anything about this?

this is what i am looking up now. i think it may need nutes so tried that tonight. ill update later

faq says yellowing leaves means N deficiency.

trashcan said:

Should i give it some chemical fertilizer on the next watering (tomorrow)? I'm not sure what to do.

Click to expand...

Yeah they look a little hungry. You have slow release nutrients in the soil already but it won't hurt them to add a quarter strength mix of grow nutrient to your next watering to help boost it a little.

Also check your pH to make sure it is not too high. A lot of soils will buffer the pH to about 6.5 but not when youre only using a cup full of soil. 6.5 is about what you are aiming for, a little lower is still ok, too high and your plants will eventually struggle to uptake nutrients.

As a grower, I must say...

Your plants need to be in 3 gallon (or more) pots ASAP!

Then water them with appropriate nutrients. It looks like they are not getting enough nutrients because the soil around them cannot hold enough. Transplant them asap, lightly mist the underside of the leaves with a B vitamin solution (very watered down) and let us know how it goes.

I am sure this will cure your dillemma.

your plants also need a humidity of 60 to 70% to grow efficiently. Circulation is SOOOOOO important. I have two small oscillating fans, an inline fan and a regular box fan in my 8x10x3 ft closet and its not enough at times. Your plants are probably deprived of CO2 as well.

trashcan said:

I forgot to attach the pictures. Here they are.

Click to expand...

Agreed, im no expert but as soon as mine started looking like that (due to no money at the time i had to wait) i transplanted out of the same cups into bigger pots and fed them for the first time, and the color came back and they really took off!!

You are prob. just starting to get root bound in those cups and they are hungry, its a 2 part issue, once i fixed that they went nuts!!


GOOD LUCK! HAPPY GROWING!!