Winter Sowing Tips For The Impatient Gardener

I don’t know about you, but we are getting antsy here in Michigan, waiting to get our hands in the thawed soil outside! We have a fresh blanket of snow, and spring seems so far away. As we plan our gardens for the seasons to follow, we have come to the point where we can experiment with the elements. Have you ever attempted to start seeds outside in the dead of winter? This technique sounds impossible until you learn more about the details of winter sowing!

Are you dreading the lack of space and lighting for the seedlings you wish to start in the next few months? This technique is calling for you too!  Winter Sowing is used by the gardeners who want to get a jump start on their season, and let’s be honest, it’s probably all of us!  Whatever your reason, this is a fantastic skill to have in your tool belt for the years to come! 

Sow Early For Better Results

Winter sowing is the art of starting seeds absolutely as early as possible. Many perennials or self-seeding annuals can be started from seed outside during months of frost or heavy snow. Choosing the right seed, maintaining proper airflow and drainage are the most vital steps in the winter sowing process. Seeds known as "hardy annuals," self-seeding annuals, or perennials specific to your region are all ideal candidates for winter sowing. Starting these varieties in cold conditions will ultimately create stronger seedlings and plants. You'll also find that this technique saves a lot of space indoors when you start the rest of your seedlings. There's also no need to harden off winder sown seedlings because they will naturally adjust as the weather changes.

The Winter Sowing Process 

Stock up on clear and opaque containers like milk jugs and 2-liter soda bottles. Anything darker will block out sunlight. If you can't see your hand's outline through the plastic, the container is too thick for sunlight to pass through. Recycle any lids; they won't be necessary here. Cut the bottom of the container horizontally -- enough to hold 3-4 inches of growing material. Remove any labels and adhesive and wash each container with warm soapy water and voilà! You've made your first mini-greenhouse! For proper drainage, poke four holes in the quartered section at the bottom of each greenhouse. Once spring arrives, add extra air vents by slicing the greenhouses' sides each time with a box cutter. Extra airflow once the weather breaks will aid the hardening-off process for the seedlings.

To begin, fill each mini greenhouse with a soilless seed starter (coco-coir/peat moss). A soil-based mixture like compost will, unfortunately, freeze in cold temperatures. Pre-moisten the mixture to help the water absorb. Plant the seeds with the technique from last week's blog post and water them in. Seal the top of the jug to the bottom with strong adhesive tape. Duct tape is a tried and true option. Make sure the container is well sealed on each side to increase the greenhouse effect. Place your lovely new mini-greenhouses in the sun-bathed areas of your garden. Be patient as you wait for the results. When spring arrives, so will the germination process! Before then, winter sowing will cold-stratify your seeds for the best results in the garden.

Troubleshooting:

A handful of issues can arise when you sow winter seeds. Monitor your new mini-microclimates to make sure all is well. On days when the temperature rises above 32 degrees Fahrenheit, you want to see condensation forming along the top of each container. If you do not see this, you may need to adjust the ventilation holes. Closing a section of airflow can adjust the container's ability to maintain the proper heat for condensation by closing a portion of the airflow. Tape the ventilation holes closed if necessary. It's vital to keep an eye on the drainage of each unit. Add additional drainage holes if the growing mixture retains too much water.

Conclusion

As you wait for spring, will you be sowing seeds early? Will it be flower seeds like lavender, calendulas, or cosmos? Mustard greens, lettuce, radishes, kale, and many others will grow very well with this amazing technique! For anyone looking to repurpose clear plastic bottles and containers, this is an awesome project to kick off the growing season a few weeks early. 

– Kaitlynn from MIgardener

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