Winter Sowing: Growing native flowers from seed for free

Manor Park greenthumb Christina Keys outlines how winter sowing help boost native species

After moving into our townhouse on Dunbarton Crt. in the spring of 2021, I set about identifying the plants in our garden. The last I identified was the most spectacular pink New England aster (Symphyotrichum novae-angliae), which bloomed from August to early November. I knew I would expand our garden space, so I wanted to learn how to get more of these beautiful plants from the fluffy seed heads that formed. I soon discovered the world of winter sowing, a local community passionate about growing native flowers from seed, and the enormous ecological benefits to planting native species.

At a local Manor Park event last December, I picked up many free seeds packets from the Ottawa Wildflower Seed Library. This “library” allows you to borrow seeds or seedlings for free with the hope that you will donate back seeds from the mature plant in future years.

Following their instructions, I grew hundreds, maybe thousands, of native perennials in a few dozen containers on my deck over winter. The steps were surprisingly simple and easy. Most native seeds need the cold of winter and the moisture of snow to germinate, a process known as cold stratification. This process breaks the seed dormancy; the seeds sprout when temperatures warm up in spring.

If you have garden space to fill, or want to remove some lawn to have more flowers, here are the simple steps to follow:

1. Check your site conditions and choose your seeds accordingly. Shade? Sun? Moist, average, or dry soil? There are native perennials for every site. Get your seeds for free outside of the Manor Park Community Centre on November 12, or from other events organized by www.wildflowerseedlibrary.ca. You can also buy them from Ontario-based websites such as www.wildflowerfarm.com and www.northernwildflowers.ca.
2. Get some pots and some potting mix or seed starting mix. Each pot will need drainage, so use plant pots or drill holes in plastic salad or yogurt containers. Fill each almost to the top with your potting mix and gently water. Bottom watering from a tray overnight works best.
3. Sprinkle seeds on soil. Gently push so each seed makes contact with soil. Add a little more soil on top according to packet instructions.
4. Label each pot with permanent marker. Mine faded last year using a Sharpie, so this year I’m trying a Staedtler Lumicolor marker.
5. Place outdoors anytime between mid-November and mid-January, avoiding a southern exposure which could trigger early germination. Ideally, cover with screens to keep squirrels out.
6. Wait! The snow will naturally protect and water your seeds. In the spring, keep the containers watered as needed. Watch for tiny seedlings to emerge.
7. Thin so that each seedling has enough space to grow. Alternatively, separate each out into small pots.
8. Once three to four inches high, plant flowers in your garden.

Using this method, I’ve converted almost my whole yard into a colourful, wildlife-friendly haven on a tiny budget. Some flowers like anise hyssop, spotted bee balm, blue vervain, and the New England asters have flowered already. Others will need another year or two to establish roots before flowering. I’ve learned about a special aspect of New England asters since growing them from seed—they have a natural variation in flower colour from deep purple to hot pink. I now have a few dozen new aster plants, each a unique colour, and as they bloom, they are providing nectar and pollen for our native bees prior to hibernation and for migrating butterflies like our endangered monarch.
It’s hard to decide what has brought me more joy — seeing the first green sprouts emerge from the pots in the spring or watching my 6-year-old marvel at my garden’s busy bees, butterflies, and birds.
Pick up your own seeds and get a tour of the MPCA’s new Manor Park Native Plant Demonstration Garden on Saturday November 12 from 10am to 12pm outside the Manor Park Community Centre at 100 Thornwood Ave.