When to Start Seeds

Great question and the answer is ‘It depends!’ Not the answer you were hoping for is it? I can narrow it down a little, but first a little background.

We start seeds inside of plants that need a longer growing season than our zone 4 area provides. If you live outside of zone 4, adjust appropriately. Many plants we grow such as tomatoes, peppers, broccoli, onions, herbs, and annual flowers are more suited for warmer climates, so to grow them here we have to give them a head start. Also, starting seeds indoors gives them some tender loving care they may not receive outside and usually results in higher germination rate.

So now you know why you start some seeds indoors early, but when should you start them? The best place to find the answer is on the seed packet and the seed packet for most of the seeds in the seed library is in the seed catalog. Either snap a photo of the packet from the catalog or jot down the information. You’ll also need the date of last frost, which in the Twin Cities is around May 13^th. You can also find information on the internet, but below is a handy chart you can reference.

Broccoli	Early Apr or 6-8 weeks before last frost
Tomato, spinach, pepper, onion, kale, Brussels sprouts, beets	Mid-Apr or 4-6 weeks before last frost
Cabbage, cauliflower	Early May or 3-4 weeks before last frost
Peas, lettuce	Direct seed as soon as soil can be worked
Carrots, parsnips, beans, corn, cucumber, melons, pumpkins, squash	Direct sow when soil has warmed around mid-late May
Oregano, rosemary, sage, thyme, chives, parsley, basil	Early Apr or 6-8 weeks before last frost
Cilantro, dill	Direct seed after last frost
Marigolds, zinnias, cosmos, morning glory, nasturtiums	Mid-Apr or 4-6 weeks before last frost
Sunflowers	Direct seed after last frost

Also, many vegetables you can get two crops in a season, such as peas, lettuce, spinach and kale by planting a second crop mid-late July.

"But wait”, you say, “I start my tomatoes at the end of March and I don’t start my morning glories inside ever and they do just fine.”

You’re right. The above chart is just a guideline. Most plants are quite flexible and whether you start those 4 weeks early or 6 weeks early or direct seed them, they will probably do ok. Also, if you search online or in gardening books, you’ll find many conflicting answers. Some key points to keep in mind is that many seedlings are not at all happy if the temperature gets below freezing or close to freezing, so if you put out your seedlings early or they start growing outside early you may need to cover them if we get a cold night in the spring. Also, some seedlings wilt if the days get exceptionally hot or dry, so keep an eye on your plants, especially at the start. In general, planting a garden is not a ‘do it once and be done’ activity. It’s a labor of love that needs some care at least weekly.

Here are some online references:

Urban Farmer: http://www.ufseeds.com/Minnesota-Vegetable-Planting-Calendar.html

University of MN Extension: http://www.extension.umn.edu/garden/yard%2Dgarden/flowers/starting-seeds-indoors/

And

http://www.extension.umn.edu/garden/yard-garden/vegetables/planting-the-vegetable-garden/

Note: This article is not intended to be about how to start seeds. That is a different topic for a different day.