Seed companies put their all into advertising blockbuster blooms that will be the big hit of the summer, and it’s all too easy to become starstruck by the seductive pictures on seed packets. Before I know it the small company of flowers I had planned to sow has blossomed into a cast of dozens, and there’s not enough room on my staging to hold them all.
Where will it end? I’ll tell you where. With windowsills and a greenhouse full of flower seedlings and me tearing my hair out trying to find space to squeeze in the stars of the show – those all-important vegetable seeds.
Winter Sowing in Milk Jugs, Soda Bottles and Other Containers
The day I discovered winter sowing outdoors in lidded containers was the day I restored sanity to my sowing schedule. Flowers provide essential snack bars and hidey-holes for pest eaters and pollinators, but they’re not the leading lights in my garden. It’s only fair that their dressing rooms are – shall we say – less glamorous than those reserved for the all-singing, all-dancing edibles.
Winter-hardy annual flowers that need cold temperatures and moisture to kickstart germination are perfect for winter sowing. Started in lidded containers, seeds can be exposed to temperature fluctuations and other winter conditions while the emerging seedlings are sheltered from damaging winds and pests.
Milk jugs and soda bottles are popular receptacles for winter sowing, but you can use any plastic container with a lid. It gives these disposable plastics an extended lifespan and removes the need for buying new containers, which may be just as (or even more) environmentally insensitive.
How to Winter Sow Annual Flowers
Making a winter sowing container is straightforward:
- Cut the bottle almost in half, leaving a small section intact to act as a hinge.
- Carefully poke holes into the bottom with something sharp for drainage.
- Fill the bottom half with potting mix – all-purpose is fine, or use your own blend.
- Sow your seeds according to the packet instructions.
- Flip the top of the bottle closed, and strap it shut with duct tape. Leave the cap off for ventilation.
- Use permanent marker to label the container with the flower name and variety.
Place your containers somewhere out of strong winds and keep an eye on them, but remember, winter-hardy annuals are not divas and don’t need mollycoddling. They’ll germinate when they’re good and ready. Growing up in natural outdoor light should produce sturdy, eager little seedlings that are well-prepared for their supporting roles in your garden.
When they're large enough to handle, they can be transplanted. Carefully tip the container up so the seedlings and potting mix fall into your cupped hand. Pull the seedlings apart, trying to preserve as much of the root system of each plant as possible. Then plant them into their final positions – no hardening off needed.
Vegetable Garden Flowers to Sow in Winter
Pretty much anything that is described as a hardy annual is a good bet for sowing in this way. Many will reliably reseed in your garden in future years, meaning you’ll only need to sow them once. The new seedlings can be transplanted to where you want them and any superfluous extras hoed off.
Choose flowers that are known as being attractive to pollinators and pest predators – cornflower or bachelor’s buttons (Centaurea cyanus), nasturtiums, forget-me-nots, calendula and sweet peas to name but a few – and these bit players will bring real depth to your garden’s summer production.