Growing plants from seed is by far the cheapest way to buy annual garden vegetables and flowers. Starting those seeds indoors extends the plants' growing season.
Indoor seeding requires a kind of reverse thinking, though. It also requires certain types of information – starting with what's on the seed packet.
For example, a Kansas gardener wanting to plant leaf lettuce or a cole crop (e.g., broccoli, cabbage, cauliflower) needs to know the local average date for putting those vegetables' container-grown transplants in the garden.
The vegetables are cool-season fans. According to K-State Research and Extension, their average transplant date is April 7 -- although a week or two earlier is often okay in southern counties. A week later can be prime time in the north.
Starting with that transplant date, the gardener can then count back by the number of weeks those varieties need to reach transplant size. Once seeds sprout, that time period can vary widely. But, for many vegetables and annual flowers, it's six to eight weeks. The indoor planting date for leaf lettuce and cole crops is around Feb. 11.
In most years, however, Kansans can still transplant those crops until mid to late April – which allows time for successive plantings. So, indoor seeding from Feb. 12 into early March can yield good results, too.
In contrast, many warmth-loving transplants typically enter the garden during mid-May. Counting backwards puts the average indoor seeding date at about March 24 for peppers and March 31 for tomatoes.
Land-grant universities provide state-specific information about planting dates and recommended varieties. Resources for Kansans are available at every county/district K-State Research and Extension office, as well as on the Web:
* Indoor planting, "count-back" days for common plants -- http://www.hfrr.ksu.edu/~/doc3300.ashx
* "Plants Recommended for Kansas" (links) -- http://www.hfrr.ksu.edu/p.aspx?tabid=731.
* "Vegetable Garden Planting Guide" -- http://www.ksre.ksu.edu/library/hort2/mf315.pdf.