Barbara Winkler

U of M Extension

Think gardening season is months away? Not so fast! As. Minnesota moves into January, you can get a head start with winter sowing, a simple, budget-friendly way to grow native plants that pollinators love. All you need are recycled containers (like milk jugs), potting soil, and seeds. These mini greenhouses sit outside all winter, giving seeds the cold stratification they need to break dormancy. Come spring, you’ll have strong, hardy seedlings ready for transplanting, no indoor lights or heating mats required.

What Is Winter Sowing?

Winter sowing is an easy germination method that uses nature’s freeze-thaw cycles to do the work for you. Seeds are planted in soil-filled containers and placed outdoors, where they get oxygen, water, light, and the right temperatures, without taking up space inside. They’ll sprout naturally as the weather warms.

When to Start: January is perfect for perennials that need cold stratification. Continue through March for hardy annuals as long as nights stay chilly.

How to Do It

1. Gather Supplies:

• Gallon milk jugs or clear plastic containers

• Potting soil (not garden soil)

• Clear duct tape

• Drill or knife for drainage holes

• Seeds, labels, and a permanent marker

2. Prep Containers:

• Clean thoroughly.

• Cut jugs horizontally, leaving a hinge.

• Add drainage holes in the bottom and ventilation holes in the lid (or leave caps off).

3. Plant Seeds:

• Moisten potting mix and add 3 inches to the container.

• Sow seeds and cover lightly per packet instructions.

• Label inside and outside.

4. Seal and Set Outside:

• Tape closed and place in a sunny, protected spot.

• Snow and rain will keep seeds moist.

Pollinator-Friendly 

Seeds to Try

• Purple Coneflower (Echinacea purpurea): Attracts native bees and butterflies

• Swamp Milkweed (Asclepias incarnata): Essential for monarchs

• Wild Bergamot (Monarda fistulosa): Loved by bumblebees and hummingbirds

• Black-Eyed Susan (Rudbeckia hirta): Supports bees and beneficial beetles

• Prairie Blazing Star (Liatris spicata): A magnet for monarchs and swallowtails

Care Tips

• Check for condensation. If dry, add water and adjust ventilation. As spring approaches, gradually open containers to harden off seedlings before transplanting.

• Why It Matters: Pollinator populations are declining, and planting native species is one of the most impactful steps gardeners can take. Winter sowing makes it easy, affordable, and eco-friendly—while ensuring your garden buzzes with life this summer.

Until Next Time, Happy Gardening!

“Every gardener knows that under the cloak of winter lies a miracle – a seed waiting to sprout, a bulb opening to the light, a bud straining to unfurl. And the anticipation nurtures our dream.”