Seed Starting: When To Start What? - Minnesota State Horticultural ...

About this time of year, the itch to start seed starting hits. Those late winter snowstorms send gardeners into their basements to find their lights and flats and double check their stash of seeds to make sure they have all they want. Some gardeners can’t wait even this long, and for them there is winter sowing.

If you prefer to start seeds indoors, most annuals and vegetables should be started between early March and mid-April in Minnesota. The University of Minnesota Extension service has a fine post about seed starting and recommends that brassicas (cauliflower, broccoli and cabbage) as well as lettuces be started indoors in early to mid-March. (Onions and celery need an even earlier start.) The brassicas are cold-weather crops and generally can be put outdoors earlier and do well in cold frames or hoop houses. A long list of popular annuals, such as petunias, ageratum, coleus and snapdragons, can also be started from seed in early March.

In mid- to late March, plant your peppers and eggplants as well as marigolds, annual phlox, cleome and hollyhocks. These all need eight to 10 weeks indoors under lights before the last frost date.

Hold off until April before doing your seed starting for tomatoes. While some folks plant them earlier, the U recommends waiting. My experience is the seedlings are stronger if they are started later. However, I’m sure with enough light and fertilizer you can grow very large plants indoors by giving them more time.

April is also a good time to do seed starting on annuals such as baby’s breath, morning glory, nasturtium, cosmos and zinnias. Some of these annuals can also be sown outdoors after the last frost date for a later bloom.

Resources

To learn more about seed starting, check out the following articles and blog posts:

How to Make Seed Starting Mix

How to Start Seeds Indoors (part 2)

Starting Annuals from Seed

JOIN A CLASS

To learn more, save a spot in an upcoming webinar or workshop!

Mary Lahr Schier is a Minnesota gardener, writer and editor and author of The Northern Gardener, From Apples to Zinnias, 150 Years of Garden Wisdom (Minnesota Historical Society Press, 2017), winner of the Silver Award of Merit from GardenComm in 2018. For 18 years, she edited Northern Gardener magazine, the publication of the Minnesota State Horticultural Society and the only magazine dedicated to gardening in USDA Zones 3, 4 and 5..

mynortherngarden.com@mynortherngarden_mary