Winter sowing is the only reason us cold climate gardeners should be starting seeds in January and February. Whether you need to plant something to lift the winter blues or just want to try something different, this is a great way to get a little jolt of good gardening endorphins at a time when they’re difficult to come by. The thermometer has been stuck around -10F for days and there’s little chance of me planting anything right now, winter sowing or not. Which makes it a great time to talk about winter sowing. If we can’t actually garden, we may as well talk about it and I’ll take full advantage of that whenever I can.
What Is Winter Sowing?
Some seeds require stratification to germinate which means a period of cold exposure is necessary to soften their seed coat and break dormancy. A freezer comes in handy for this or you can winter sow and make it a whole lot easier. Certain flowers, vegetables and herbs respond well to this seed-starting technique.
Benefits of Winter Sowing
Most importantly, winter sowing means you’re gardening in the middle of winter! So for me, that’s number one. But here are some very close seconds to consider. The responsibility of looking after those seeds all winter/spring long isn’t completely your responsibility. Winter sown seed – from the stratification process, to germination, to growing, to hardening off – is acclimated to outside air. They’re entirely at the mercy of Mother Nature. Which means you’re not responsible for springing for grow lights, watering your seedlings and fussing over them all winter long. It also means they’re pretty sturdy little seedlings.
The fact that you’re using items from around the house like empty water jugs and 2-liter containers also means there’s no extra cost after you purchase seed and seed-starting mix. With no heat mats, humidity domes or pots to buy, winter sowing is an inexpensive way to grow as many plants you’d like.
Maybe it’s just me but there’s something hopeful about checking on your seeds in March and finding little bits of bright green poking through the soil. It makes me smile every time to know that in spite of negative temperatures and thick blankets of snow hugging the containers, something wonderful is happening inside and that brings joy in the most meaningful way.
When to Winter Sow?
Plant too early, like in autumn, and you risk the young seedlings not surviving the bitter months ahead. For this reason, I do all my winter sowing in February but your timing depends largely on your climate and location. You can do it in December and January too. Most seeds that require stratification need several months of cold, moist conditions to break dormancy. Winter sowing in early to mid-February is early enough in my zone 6a climate.
Winter Sowing Seed List
There are lots of seeds that respond well to winter sowing. Here’s a list of some perennials, annuals, vegetables and herbs to try. No doubt you’ll discover others!
Supplies for Winter Sowing
You don’t need much and that’s one of the benefits of this seed starting method! Here’s the list:
- Empty milk jugs or 2-liter bottles
- Pre-moistened seed starting mix. Moisture is necessary for softening seed coats.
- Labels and waterproof marker
- Duct tape
- Sharp point for creating drainage holes. I use the end of my scissors.
My Winter Sowing Method
Step 1: With scissors, begin cutting horizontally about four inches from the bottom of your vessel. This will ensure you have enough soil volume to sustain the roots of your seedlings as they mature. Don’t cut all the way around as you want to leave a “hinge” at the back of your container. I like to place my hinge beneath the handle of my gallon container.
Step 2: Every container needs good drainage and the same is true for winter sowing. I poke four holes in the bottoms of my containers. You can use the end of your scissors or a screwdriver.
Step 3: Fill your jug with three to four inches of pre-moistened seed starting mix. Avoid potting mixes with fertilizers as these can burn seeds and sabotage your entire winter sowing operation.
Step 4: Plant your seeds at the recommended depth on the seed packet. I sow liberally, sometimes closer than an inch between seeds, to ensure success. Not every seed will germinate.
Step 5: Using your marker, write the name of your seed and the date sown on your markers. Add them to your containers.
Step 6: Once the seeds are planted, close the lid and seal the top and bottom halves together with duct tape. I don’t use the cap as leaving it open allows good ventilation.
Step 7: And finally, write the name of the seed on the outside of the container.
Where to Place Winter Sown Containers
The best spot is one with plenty of sun and good shelter. Against the raised beds in my veg garden is perfect for me. The southern exposure coupled with the dark stained raised beds makes for a cozy space away from gusty winds. Against your house or shed will work too, as long as there’s plenty of sun to warm them. And don’t be concerned about snow and ice covering your containers. They not only work their stratification magic but they also serve as excellent insulators.
As your containers endure freezes and thaws, the seeds will slowly awaken. One day, you’ll peak into your water jugs to discover the most promising glimpses of green. That’s a good day! Your jugs shouldn’t need any supplemental watering, but in the event of a long stretch of warm temps, you should open them and check the soil. If it feels dry, give them a drink and reseal the containers.
When to Plant Winter Sown Seedlings
Anytime! The beauty of winter sowing is seedlings require no hardening off to acclimate to outside air, wind and light conditions. They have that licked! For months they’ve endured whatever Mother Nature threw at them and now it’s time to settle into more permanent digs.
I’d love to know what kind of winter sowing you’ll be doing this year. Tell me in the comments.
If you’re wondering why I’ve included this photo of Solo Blue Picotee lisianthus, it’s because I’ll likely never grow it and this may be the only time I write of it on this blog. I say likely because there’s always that chance that I will attempt it. You never know what flower will overcome a gardener at any given time. I’ve included it because earlier in this post, I mentioned there’s no reason why a cold climate gardener would sow seeds in January. There are actually two. The first being winter sowing and the second if you’re determined to have lisianthus in your garden this year. They need to be sown 16-22 weeks before your average last frost date.
That would put me somewhere in mid-December and that means there’s always next year!