Withering lower leaves on 4-6 wk. seedlings

[Greatgardens]

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?

[KarenO]

Any photos?
What are you fertilizing with?
KarenO

[Greatgardens]

Here is a picture of "Sweet Satsuma" -- an de-hybridized version of Orange Pixie. This is the typical way it happens (but not always) -- the withering starts at the outward leaves and works back to the stem. Then the whole branch falls off. If you look closely at the stalk, you can see this one has lost at least three leaf branches. I typically will not fertilize, but have experimentily fertilized with a pinch of dry organic fertilizer when potting up or more often 1/2 strength blue water. I typically use Burpee's Organic Coir Seed Starting Mix or Metro-Mix. I used to use sifted Miracle-Gro Potting Mix with a little added Perlite.

[Greatgardens]

Sure didn't intend for the picture to end up sideways!

[KarenO]

A plant that needs fertilizer will use up nutrients from older leaves to feed the new growth. A plant that size needs some fertilizer I think.
KarenO

[RayR]

I would agree, it looks a bit stretched and stressed. Was it fertilized?
I don't understand why someone would not fertilize a seedling especially if there's no starter fertilizer charge built into the mix. Then too much of that blue water stuff can burn too.

[Greatgardens]

Originally Posted by KarenO

A plant that needs fertilizer will use up nutrients from older leaves to feed the new growth. A plant that size needs some fertilizer I think.
KarenO

What fertilizer would you recommend, and when?

[tryno12]

I know I have been fertilizing my seedlings that are close to bloom transplants nearly daily for a month @ 50% MG and 50% Alaska Fish 5-1-1 and things great. Was worried 2 weeks ago when I saw a few leaves turn brown and / or pale.... so I over watered, then drained, next day re fertilized... when they are young it is a daily "sweat" / worry for me to keep them maximized for growth but don't kill 'em...........

[KarenO]

Originally Posted by Greatgardens

What fertilizer would you recommend, and when?

The easiest option is 1/2 strength miracle grow.
I would use the balanced all purpose for seedlings.
If worried about organic then a liquid kelp or fish fertilizer at half strength also
KarenO
For myself I feed my seedlings weekly from potting up to planting out. I see a lot of conflicting info regarding fertilizer in seedlings many say none is required which I think is quite misleading for folks. Tomatoes are fast growing heavy feeders and Require supplemental fertilizer early if there is none in the potting mix and even if there is, can use it up before planting up from a small nursery pot or solo cup size. Learning to read seedlings for early signs of deficiency takes practice but basically anything that is not lively green and growing well is Not normal or expected in a Regular tomato seedling.
KarenO

[RayR]

Originally Posted by KarenO

The easiest option is 1/2 strength miracle grow.
I would use the balanced all purpose for seedlings.
If worried about organic then a liquid kelp or fish fertilizer at half strength also
KarenO
For myself I feed my seedlings weekly from potting up to planting out. I see a lot of conflicting info regarding fertilizer in seedlings many say none is required which I think is quite misleading for folks. Tomatoes are fast growing heavy feeders and Require supplemental fertilizer early if there is none in the potting mix and even if there is, can use it up before planting up from a small nursery pot or solo cup size. Learning to read seedlings for early signs of deficiency takes practice but basically anything that is not lively green and growing well is Not normal or expected in a Regular tomato seedling.
KarenO

It never made any sense to me too to not feed seedlings. That's like saying if you starve your children they'll grow up big and strong.

[tryno12]

Thanks Karen, also I was not clear in my above post: I do use 50% strength MG and 50% Fish Fertilizer at the same time. I also use Myco Blast for the roots as a one time application( I am going to try to freeze all the Myco Blast I have left - used very little and I hate to toss it)
Pete

[Greatgardens]

Thanks. I guess what I can easily do is be less haphazard in my fertilizing. I'll come up with a plan and implement it on my next seed planting -- which will be tomorrow or the next day. The only thing that will be different from my earlier plantings is that everything will be a bit warmer, and I have less crowding since everything else will already be in planted outside for the summer. Will post my results in 4-6 weeks.

[ddsack]

I wonder if what you have is part of the CRUD problem mystery that some seedlings grown indoors have. It all goes away when they are outside in natural sunlight and in the ground. In years past, there were many threads about it ... here are just a couple ...


http://www.tomatoville.com/showthrea...highlight=CRUD


http://www.tomatoville.com/showthrea...CRUD+seedlings

[Greatgardens]

That's very interesting! Had not heard of CRUD before. It gives me some ideas, but again along the line of improved fertilization. My next batch will be planted in sifted Metro Mix with perlite added. I will add fertilizer, probably some bone meal and a little Myco Grow. I had not planned on any dwarfs, but since they seem the most susceptible, I'll probably add a couple.

[zipcode]

I really don't think that's a lack of nutrition problem.
Could be a toxicity of some kind, maybe due to water? But hard to say.