Winter Sowing Seeds: How to Give Flower Seeds a Head Start

Some Seeds Should Be Sown Before Spring

September 30, 2021
Butterflies on Milkweed

Some flower seeds are best sown in fall and winter. Yes, winter! Many flower seeds need an extended period of cold in order to germinate. This is called stratification. Discover what we call “winter sowing” and how to give flower seeds a head start, why you should start some seeds earlier (before spring), which seeds are best sown in fall or winter. 

What Is Winter Sowing?

Those of us in cold climates don’t usually think of fall or winter as times to be planting seeds outside, however, in the case of many perennials this is definitely the time to do it! Many flowers like a period of cold, wet weather to germinate.

Take a look around you; our favorite native plants, annuals, biennials, and perennials are laden with seeds, dropping them where they will sprout next spring. Follow nature’s lead and take advantage of this process to add new plants to your landscape or just increase the numbers of ones you already grow.

Don’t worry; waxes, hormones, and heavy seed coats keep the seeds from sprouting at the wrong time. The alternate freezing and thawing in cold moist soil breaks these down so the seeds are ready to grow come spring!

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Add some fancy double columbines to your garden!

When it comes to winter sowing seeds, there are several ways to do it.

  • Just let nature do the work and let the seeds drop. In the spring, you can dig up and move the plants where you want them to grow. Be careful when raking this fall since it can disturb or move the seeds and mulch can smother them. You may want to mark the spot so you can find them come spring. Discover 20 self-sowing flowers
  • Or, you can scatter seeds where you would like them to grow. This works best for taprooted plants and ones that dislike transplanting including poppies, lupine, larkspur, bachelor buttons, and lunaria. I have had great luck scattering poppy seeds over the snow in late winter. 

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Lupine dislike being transplanted.

  • Or, after a killing frost, sow the seeds in a nursery bed where you can have more control of the surroundings and keep an eye on them easily. Once they are up and growing well, next spring you can move them to their new locations. I prefer this to scattering, especially when I have purchased the seeds rather than collected them.
  • If space in your garden is at a premium, you can start the seeds in pots outdoors. Just be sure to use pots that won’t crack over the winter. Again, do this after a killing frost but before the soil freezes solid.
  • If you prefer starting the seeds indoors, you can trick them into sprouting by giving them a period of moist cold in the fridge. You can either plant the seeds and place the containers in a plastic bag and put them in the fridge or other cold spot where they will stay below 45 degrees for at least 2 months. If you don’t want pots of dirt in the fridge just place the seeds in plastic bags with a bit of moist soil or vermiculite. Don’t place dry seeds in the fridge or freezer to stratify them. Moisture and cold are the key elements.

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Joe-Pye weed is a lovely fall-blossoming plant that butterflies love. Its seeds need a period of cold to germinate.

Which Seeds Should Be Sown in Fall or Winter?

Some of the plants that benefit from chilling or germinate best when planted in the fall are:

  • coneflowers (Echinacea),
  • Asclepias (milkweed and butterfly weed)
  • Lobelia,
  • delphinium,
  • gas plant,
  • rosemary,
  • yarrow,
  • feverfew,
  • foxglove,
  • dianthus,
  • Verbascum,
  • columbine,
  • penstemon,
  • asters,
  • rudbeckia,
  • Nicotiana,
  • Nigella,
  • Scabiosa,
  • Helianthus, and
  • geranium.

If you are trying to establish a sunny meadow garden, many wildflower mixes do better when sown in the fall after a killing frost or two.

Don’t cover small seeds, just press them into the surface of the soil—well-drained, weed-free soil. Over-sow by about 20%.

Fall is usually moist and cool so watering isn’t needed as often. Water once and let seasonal precipitation and low temps do their magic until spring. 

Planting a mini-nursery of perennials from seed is a budget-friendly way to add plants to your garden, especially if you have collected the seeds for free!

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The poppy seeds I have scattered over the snow have always germinated best for me.

Learn more about saving flower seeds.

Save some plant with seeds to feed the birds!

About This Blog

Get inspired by Robin Sweetser’s backyard gardening tips and tricks. Robin has been a contributor to The Old Farmer’s Almanac and the All-Seasons Garden Guide for many years. She and her partner Tom have a small greenhouse business and also sell plants, cut flowers, and vegetables at their local Farmer’s Market.

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