Some lettuce seedlings waiting to be transplanted
Much of our garden starts indoors. We find it more efficient to start seeds indoors than sowing seeds outdoors. For many vegetables it is necessary to start plants indoors because of our relatively short growing season.
If one were to start tomatoes from seed outdoors it would delay the harvest for as much as a month. For those of us who only eat tomatoes in season—that is, from our own gardens—that lost time is not acceptable.
We start some seeds under lights in the cellar
We used to start many seeds in small pots, wait for them to germinate and grow a little, then separate them to plant out. More recently we have begun using six-packs and growing only one seedling in each of the six cells.
We actually sow two or three seeds in each cell and then cut off any extras. In the event nothing grows in one of the cells we will let two develop in one of the other cells, but that is actually fairly rare.
Once our seeds germinate we keep them under lights in the cellar.
Some seed trays on the bay window ledge
We put some of the warmer weather vegetables such as eggplant, peppers and tomatoes in the bay window in the family room (which is warmer than the cellar).
Seedlings in the window
A week or two before seedlings are to be transplanted outside we begin putting them out in our driveway to be "hardened off." They go out for about an hour the first day and then the time is gradually increased. That gets them accustomed to wind and sunlight.
If the weather is bad (rainy or cold) they will stay in the cellar under lights.
Because of damage from cabbage white butterflies we put the cole crop (kale, Asian greens, collards, broccoli) seedlings in a frame with a screened top. This is particularly important later in the year when starting the second plantings of these vegetables because the butterflies seem to be more active then.