How to Winter-Sow Flowers and Which Seeds Work Best

What Is Winter Sowing?

Those of us in cold climates don’t usually think of January and February as times to plant seeds outside; however, for many perennials and hardy annuals, this is definitely the time to do it! Many flowers like a period of cold, wet weather to germinate. (Wait until late winter or early spring to plant tender annuals.) 

Look at nature: 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 number 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!

Which Flower Seeds Are Good for Winter Sowing?

Any plant that is “hardy” in your zone is fine to plant in winter. These flowers have no problem with snow or frost and, in fact, need the cold. Here are some of my favorite flower seeds for winter sowing in January or February.

• Baptisia
• Columbine
• Foxglove
• Hollyhock
• Buddleja (butterfly bush)
• Forget-me-not
• Lavender
• Alyssum
• Lupine
• Bachelor Button
• Coreopsis
• Delphinium
• Larkspur

How to Winter Sow Flowers

There are several ways to sow winter seeds. 

In the Fall

1. Just let nature do the work and let the seeds drop. Discover 20 self-sowing flowers. Or, scatter seeds where you would like them to grow. This works best for plants that dislike transplanting, including poppies, lupine, larkspur, bachelor buttons, and lunaria. I have also had great luck scattering poppy seeds over the snow in late winter. 
2. Or, after a killing frost, sow the seeds outside 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, you can move them to their new locations next spring. I prefer this to scattering, especially when I have purchased the seeds rather than collected them. Don’t cover small seeds; just press them into the surface of the soil—well-drained, weed-free soil. Over-sow by about 20 percent.
3. 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.

In the Winter

1. 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 in another cold spot where they will stay below 45°F 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.
2. To winter-sow seeds outdoors, the classic method is to simply seed hardy perennials and annuals outside in recycled milk jugs or water jugs in January and February. You simply cut 1-gallon jugs in half below the handle so the bottom becomes a tray. Add drainage holes, 2 to 3 inches of potting soil, sow seeds, and moisten. Cover the lid of the jug and tape it to the bottom. Now, put the jugs outside in the sun but sheltered from the wind. Let nature do its thing. In early spring, look for seedlings. Open the tops as it gets warmer. See 5 Steps to Winter Sowing in Milk Jugs.

What’s great about winter sowing is that you don’t waste time or money trying to grow lanky seedlings on windowsills. You’ll have strong, sturdy starts, and it’s really easy because nature does most of the work!

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!

Save some plants with seeds to feed the birds!