When we started Peck & Petal last year, our biggest constraint on choosing how many plants to grow was space. We had plenty of space in the garden, but not enough space to start all those tiny seedlings under lights in our basement. We had to get creative on how to start our seeds.
We learned about winter sowing from, of course, YouTube. If you are a home gardener or aspiring farmer,YouTube has a wealth of information. To make a long story short, winter sowing doubled the amount of seeds we started, was incredibly easy, and produced healthy plants that didn't need a full hardening off period.
I wanted to create a quick resource for you that shares the basics of winter sowing with step-by-step instructions along with our favorite varieties to winter sow. Let's get to it!
What is Winter Sowing?
Winter sowing is planting seeds in mini greenhouses during the winter months. This is especially helpful if you are in a colder climate like us in Michigan or anywhere temps drop below freezing in the winter months. Winter sowing takes common household single-use plastics such as clear milk jugs, salad clamshells, or rotisserie chicken domes and turns those items into mini greenhouses. Seeds are planted in these items in the winter months and set outside. When the light requirements and temperature for the seed variety are right, the seed germinates and grows right in the container with no need for additional water or artificial light.
How to Winter Sow
1. Collect Your Containers- we prefer milk jugs and collected over 100 from friends last year. Note that you must use clear containers for the light to get through to the plants. This is a great way to recycle single-use plastics.
2. Clean Your Containers-make sure the containers are well cleaned before use.
3. Prepping to Plant-Items like clamshells and domes already come in two pieces. Milk jugs need to be cut. Cut the jug around the base of the handle, leaving the bottom of the handle intact. It will act as a hinge. See picture below of an example milk jug. Poke small holes in the bottom of your containers to allow excess water to drain out.
4. Add Your Seeds and Soil- fill the bottom of the cotainer about half way with a good potting soil or seed starting mix. Press your seeds into the soil and cover if light is not required for germination (check the back of you seed packets for growing details). Lightly water until soil is damp but not saturated.
5. Seal it Up and Set it Out-Seal the cut seam of the milk jug with duct tape. You may also wish to label your jug with the variety of crop. DO NOT PUT THE CAP BACK ON THE JUG! This helps the plants from getting too hot and allows rain water in. Set the jugs out in a space that drains well and won't be disturbed by pets or wild animals.
Once the weather warms in the spring, check your containers for growth periodically. It's so fun finding your first seedling in a winter sown jug! As temperatures rise, open the seam of the milk jug to let in additional light during the day and prevent the young plants from overheating.
After your plants are a few weeks old in the jugs, you can plant them out according to their instructions. Some plants can be planted out once danger of a hard freeze is past, but many will do better if you wait until after your last frost.
What Varieties Should I Winter Sow?
My favorite varieties to winter sow are the hardy annuals. These plants can take a bit of chill or frost, and some even grow better after being in the cold. Here are the varieties we are winter sowing for 2020: Feverfew
Last year we even wintersowed heat lovers like Zinnias with great results.
You really can't go wrong with winter sowing. It's a cheap, easy, and resourceful way to start your garden. I'd love to hear about your winter sowing adventures or questions.