I now have seedlings growing in every pot that I’ve planted so far. Germination rates are quite high, even though some of the seeds are several years old. The early tomato pot is on the left, then the peppers (front four) and eggplant (rear two) and finally four types of cabbage are in the peat pots on the right.
The seedlings need to be watered every few days. The peat pots dry out the quickest, probably because they are porous and thus can lose water more easily than the plastic pots. I used soluble fertilizer (Miracle-Gro brand, but there are other choices) when I watered them earlier this week. Be aware that these fertilizers come in different formulations. The most important numbers are the amounts of nitrogen, phosphorous, and potassium in the fertilizer (N-P-K). The most common formulation is 24-8-16, but the high amount of nitrogen will promote too rapid growth of the green parts of the plants. A fertilizer with a higher amount of phosphorous will promote balanced growth, so the plants will develop strong roots. I use “Rose Plant Food,” which with a formulation of 18-24-16 is more to my liking. I use 1/4 teaspoon of the fertilizer in a quart of water, once every couple weeks at most.
I have the seedlings in front of a large window and under fluorescent grow lights for additional light. If they don’t get enough light, seedlings will become tall and spindly, subject to wind damage after they are transplanted into the garden.
I originally built my light stand to work with seedlings growing atop a radiator. Now that I have forced air heat and the radiators are gone, I put the seedlings on some plant stands so that they are close to the grow light. The light hangs from chains that allow me to adjust the height as the seedlings grow.