How to Sow Hardy Seeds Outdoors in Pots (Easy Winter Method)

Here’s an easy method for planting hardy seeds, including native species, in pots outdoors during the winter. By keeping the seeds in pots, you prevent them from washing away. After undergoing natural stratification, the seeds will sprout in the spring.

Another popular method is the winter sowing milk jug method which can be used for any cold-tolerant seeds. Each method has advantages and drawbacks depending on what you are trying to grow.

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Growing Native Plants From Seed

Are you ready to add more native plants to your garden?

Many of us are transitioning to native plants these days for good reasons.

By choosing native plants, we’re providing local wildlife with the same plant species they have co-evolved with. These inter-dependent relationships between plants and animals are what bring ecosystems to life.

Wildlife = animals in our gardens from microscopic to four-legged animals including microbes, fungi, invertebrates, insects, birds, mammals, amphibians, and reptiles.

To sustain that life, we need biodiversity. This means not only growing a diverse selection of native plants but ensuring each plant species also offers genetic diversity.

This is why growing from seed, or buying native plants grown from seed, is beneficial. Sexual reproduction makes each seed one-of-a-kind—something you do not get from cloning (growing from cuttings). It’s that genetic diversity that brings resilience and adaptability in challenging conditions.

How do I find the right native seeds for my garden?

• The first step is to find a trusted source to recommend native plants for your area. This may be a local conservation authority, extension office, native seed grower, or environmental group. The goal is to choose indigenous plants that serve an ecological purpose—helping sustain the local ecosystem.
• From there, you want to narrow down your selections to suit your specific growing conditions including soil type, water and drainage, light, space available, as well as aesthetics.

Most of us live in developed areas where the native soil is long gone. The best native plant choices will suit our existing conditions requiring few if any inputs like supplemental watering or fertilizers.

How to Sow Native Seeds

Native plants that originate in cold climates are equipped to survive winter conditions. The plants produce seeds that ripen and drop to the ground in fall, endure everything winter can throw at them for months on end, and, eventually, germinate.

Except it’s not that perfect.

Most seeds never germinate for any number of reasons. Some are duds. Some land where they can’t sprout. Animals eat them. Rain washes them away. And so on.

And that’s why plants produce such an abundance of seeds—it increases the odds of successful offspring.

The good news for us is, we don’t have to sow thousands of seeds to garner a dozen. Instead, we can protect what we sow (see below) while still exposing the seed to the conditions they need.

Timing

Late fall or early winter is the time to sow native seeds outdoors in pots.

Most seeds will need at least a few months of winter exposure.

Some native seeds germinate after one winter, others take a year or longer and/or may not flower until their second year.

Seeds

All native seeds from cold climates can survive winter outdoors.

While some just chill in the cold weather, insulated by leaves and snow. Others specifically need moisture to soften their tough seed coats along with cold stratification. This explains stratification in detail.

While the method described below is the same for sowing all native seeds, it’s always wise to read the seed packet to check for any special sowing instructions. Some really tough seeds may also need scarification (nicking the seed coat) prior to sowing.

Native Seed Suggestions (if suited to your region)

Many of these plants are native to parts of Canada and the United States (in colder regions). Always check trusted local plant lists before you buy or sow.

Slow to Germinate

These are examples of native seeds that take two years to germinate. If you sow them, be prepared to take care of the pots for the long haul.

Supplies

• Native seeds | Local to your region, suited to your growing conditions.
• Pots or trays | At least 3-inches deep
• Marker and Tags | To label your pots
• Potting mix | There are lots of opinions on which is best: potting mix, potting mix with compost, or garden soil. I use potting mix.
• Mask | Wear a mask to avoid inhaling fine particles from potting mix and soil
• Topping (optional) | Some gardeners top the pot with a fine layer of sand, grit, or sawdust to help keep the seeds in place. I just use potting mix.
• Bin | To hold your pots. I add drainage holes to the bin, otherwise the pots become waterlogged with rain or melting snow in spring.
• Hardware cloth | To cover the pots and keep animals out. I use scraps of hardware cloth or squirrel screens.
• Rocks or Bricks | To hold hardware cloth or screen in place.

Steps

1. Moisten potting mix with water. It should be moist enough to form a clump when grasped in a ball but not so damp that it drips excess water.
2. Fill pots with moist potting mix, gently pressing it down as you go to remove air pockets. Leave one-half inch at top for watering. Sit pots in bin.
3. Sow seeds at recommended depth (generally as deep as the seed is wide).

4. Water newly sown seeds.
5. Optional: sprinkle fine layer of sand, grit, or sawdust over surface to help keep seeds in place.
6. Place bin (with pots) outdoors preferably in shade (not direct sun) away from overhangs (that could drip water).
7. Cover with hardware cloth or squirrel screen held in place with rocks or bricks to hold screen in place.

Maintenance

Set reminder in your phone to check on pots every few days. Snow, rain, hail,—it’s all fine—you just don’t want the weather to upset the pots, animals to get at them, or the potting mix to dry out.

If your bin does not have drainage holes, you may also need to routinely pour out any excess water.

What to Expect

After weeks or months, as the weather warms and the days become longer in spring, some seeds will start to germinate.

Others may take months or longer—even seeds of the same species vary with their timing.

Unlike the winter sowing method using closed containers like milk jugs, these seeds won’t sprout until outdoor conditions are favorable.

Transplanting

As time passes, you will eventually have pots filled with young plants.

Depending on the timing, you may separate the clumps and give each plant (or small cluster of plants) their own larger pot, or plant directly in the ground.

Some gardeners like to keep the young native plants in pots until fall planting time or hold off until the following year. I like to keep them in pots until they are strong, young plants which can often take a year or so.

Frequently Asked Questions

Resources

Read More

• Wild Seed Project | How to Grow From Seed
• Joe Gardener | Joe Lamp’l interview with Heather McCargo (Wild Seed Project)
• Lupine Gardens | Understanding the Fundamentals of Native Seed Germination
• Prairie Moon Nursery | How to Grow a Prairie From Seed

Eco-Beneficial Gardening Books

I recommend these books because they get gardeners excited about ecological gardening and the incredible relationships between plants and animals. Our future is in our hands!

1 The Pollinator Victory Garden | Kim Eierman | Win the War on Pollinator Decline with Ecological Gardening; Attract and Support Bees, Beetles, Butterflies, Bats, and Other Pollinators

2 A Garden for the Rusty-Patched Bumblebee: Creating Habitat for Native Pollinators: Ontario and Great Lakes Edition | Lorraine Johnson, Sheila Colla | All the information gardeners need to take action to support and protect pollinators, by creating habitat in yards and community spaces, on balconies and boulevards, everywhere!

3 The Gardener’s Guide to Native Plants of the Southern Great Lakes Region | Rick Gray and Shaun Booth | Distills all the information essential for growing 150 species of garden-worthy native plants into a single, at-a-glance guide.

4 Bringing Nature Home: How You Can Sustain Wildlife with Native Plants | Doug Tallamy

5 Garden Allies: The Insects, Birds, & Other Animals that Keep Your Garden Beautiful and Thriving | Frederique Lavoipierre

6 The Humane Gardener: Nurturing a Backyard Habitat for Wildlife (How to Create a Sustainable and Ethical Garden that Promotes Native Wildlife, Plants, and Biodiversity) | Nancy Lawson

~Melissa the Empress of Dirt ♛