Question
Hi,

I started tomato, cukes and peppers from seed last month. I am using a T5 light.Some plants look pretty good some are still small. I am getting some yellowing of the leaves on the tomatos and cukes. Peppers are still small.I am in the Chicago area and it has been cold. I have this set up in the basement and it is still cool down there. I was hoping by this time the weather would be better, but it is not. What can I do to help these seedlings along and avoid the yellowing. I am using a 20-20-20 fertilizer.Thanks for your time.

Answer
The two keys when starting seedlings in a cool basement are temperature and watering.

Seedlings need temperatures at or above 70F. When starting them in a cool basement, you need heating pads. These are sized specifically for flats and can be purchased at most garden centers.

Because the temperatures are cooler, you also need to water less since today's growing mediums retain water much longer. If you over water, the plants are deprived of nutrients due to depletion. The roots also tend to become water-logged, resulting in them not being able to absorb the nutrients. This is what causes the leaves to yellow and the plants to be stunted.

Only water when the top 1/2" of soil becomes totally dry. You can also purchase a moisture meter to better determine when the plants need watering.

I hope this answered your question. Good luck, and enjoy the weekend.

Regards,

Mike