Withering lower leaves on 4-6 wk. seedlings

Greatgardens · May 18, 2020

I get his problem almost every year now, and I'm not going to take it any more!

Maybe someone has some ideas. When my seedlings emerge, and for several weeks, they grow (and look) just great, but after they have about 3 good sets of true leaves, the lower leaves start withering and falling off. I can't figure it out -- is it watering, maybe not enough light, or?

More vigorous varieties seem to not have a problem or at most, just lose their seed leaves. I've tried different seed starting mixes, fertilizing/not, and it seems to have no effect. When I look at the roots, the more vigorous plants have good root systems, while affected plants have pretty spindly root systems. Far more dwarfs seem to have this issue than det/ind. varieties. Some end up looking like little "palm trees." When the weather gets warm enough to put them in the cold frame, nearly all seem to grow out of it. They don't die -- they just look like heck. Not all dwarfs do this. I have minimal problems with several good performers such as Dwarf Pink Passion.

I'm starting to think that not enough light is the major issue. As the plants grow, they become more crowded, and would tend to shade the lower leaves. (?) I don't remember this problem when I used Gro-Lux WS 40-watt bulbs (for many years). OTOH, I used to grow nothing but ind. hybrids, so that might enter into it. I have to use artificial light, and I use a mix now of "pink" LED's and daylight and regular Gro-Lux T8's.

Any thoughts?

May 18, 2020	#1
Greatgardens Tomatovillian™ Join Date: Feb 2010 Location: Indiana Posts: 1,124	Withering lower leaves on 4-6 wk. seedlings I get his problem almost every year now, and I'm not going to take it any more! Maybe someone has some ideas. When my seedlings emerge, and for several weeks, they grow (and look) just great, but after they have about 3 good sets of true leaves, the lower leaves start withering and falling off. I can't figure it out -- is it watering, maybe not enough light, or? More vigorous varieties seem to not have a problem or at most, just lose their seed leaves. I've tried different seed starting mixes, fertilizing/not, and it seems to have no effect. When I look at the roots, the more vigorous plants have good root systems, while affected plants have pretty spindly root systems. Far more dwarfs seem to have this issue than det/ind. varieties. Some end up looking like little "palm trees." When the weather gets warm enough to put them in the cold frame, nearly all seem to grow out of it. They don't die -- they just look like heck. Not all dwarfs do this. I have minimal problems with several good performers such as Dwarf Pink Passion. I'm starting to think that not enough light is the major issue. As the plants grow, they become more crowded, and would tend to shade the lower leaves. (?) I don't remember this problem when I used Gro-Lux WS 40-watt bulbs (for many years). OTOH, I used to grow nothing but ind. hybrids, so that might enter into it. I have to use artificial light, and I use a mix now of "pink" LED's and daylight and regular Gro-Lux T8's. Any thoughts?