Cotyledons falling off tomato seedlings

cgantt · March 31, 2011

This year I bought most of my seeds from Ferry Morris, due to lack of time and knowledge of better companies like Johnny's. I sowed 45 better boy hybrid, 28 early girl, and 34 brandywine. These are not all of the tomatoes I planted but are the only ones I am having problems with. The germination rate was very good, 40 better boys, 27 early girl and 28 brandywines germinated.

I started them in a 128 cell plug tray in a DIY seed starting mix that I got from a friend who works in a nursery. The plug tray was heated on a mat and had a 4' shop light 2 inches above the tray. I watered twice daily with a spray bottle and well water. The seedlings sprouted and once they reached about 3" I transplanted to 72 cell flats which were filled with Pro-Mix Ultimate Organic Mix.

The problem is that the cotyledons on about 40% of the seedlings have fallen off and the stem shrivels up and dies. Since transplanting to the 72 cell flats they have resided in my greenhouse which has had an average temp of 80f due to a space heater and a fan. This problem is unique to the Ferry Morris seeds. The ones I bought from Johnny's had almost a 100% germination rate and have their first sets of true leaves now.

Am I watering them too much, not enough, or is there something else at work here?

March 31, 2011	#1
cgantt Tomatovillian™ Join Date: Mar 2011 Location: Aiken, SC Posts: 15	Cotyledons falling off tomato seedlings This year I bought most of my seeds from Ferry Morris, due to lack of time and knowledge of better companies like Johnny's. I sowed 45 better boy hybrid, 28 early girl, and 34 brandywine. These are not all of the tomatoes I planted but are the only ones I am having problems with. The germination rate was very good, 40 better boys, 27 early girl and 28 brandywines germinated. I started them in a 128 cell plug tray in a DIY seed starting mix that I got from a friend who works in a nursery. The plug tray was heated on a mat and had a 4' shop light 2 inches above the tray. I watered twice daily with a spray bottle and well water. The seedlings sprouted and once they reached about 3" I transplanted to 72 cell flats which were filled with Pro-Mix Ultimate Organic Mix. The problem is that the cotyledons on about 40% of the seedlings have fallen off and the stem shrivels up and dies. Since transplanting to the 72 cell flats they have resided in my greenhouse which has had an average temp of 80f due to a space heater and a fan. This problem is unique to the Ferry Morris seeds. The ones I bought from Johnny's had almost a 100% germination rate and have their first sets of true leaves now. Am I watering them too much, not enough, or is there something else at work here?