Living in the midwest, winter gets kind of gray. Gray skies, gray clouds, gray sludge. Right around February, I start aching for my garden and the feel of dirt. That’s when I know it’s time to start winter sowing some seeds.
The idea behind winter sowing is to start seeds outside in the winter, so they go through a freezing and thawing process, which helps them germinate. One trick to speeding up this process, is to sow the seeds in a mini-greenhouse, because once spring hits, the soil in greenhouse will thaw faster than your garden, and your seedlings will already be hardened to the environment.
It’s easy, it’s very inexpensive, and it actually saves a lot of money because you don’t have to buy any starter plants.
Here’s what you need:
- Clean, upcycled plastic containers: I like to use gallon jugs from milk or water, but liter-sized water bottles and take-out containers do well too.
- Duck tape
- Potting mix
- Seeds
- Exacto knife or scissors
- Paint pen
First, pour some potting mix into a really large bowl. Gradually add water to the mix, gently working the water into the mixture until the soil starts to come together. It goes from a light brown to a dark brown color.
Next, prep your container. When I use a milk jug, I use scissors or a sharp knife to make an incision just to the left of the handle, about four inches from the bottom. Then I cut all around the container until I have a hinged lid, as shown in the picture below. Leaving the cap on while cutting helps the container retain its shape. If the container warps though, no worries, because you can always reshape it later. Now, flip the container over and poke about five or six drainage holes in the bottom.
The top of the container is still hinged to the bottom of the container. 
Be careful when you poke those holes!
At this point, you can remove the screw-top cap from the container and toss it. Fill the bottom of the container with two to three inches of soil.
Gently pat down the soil, and you’re ready to sow your seeds! I usually sow anywhere from five to nine seeds, depending on the spacing required. You can use a pencil to create indentations to the depth required by the seed, and then just drop the seed in and pat soil on top. This February, I planted basil, green beans, radish and snap dragons. In March, I’ll probably add tomatoes and spinach.
Once you’ve sown the seeds, replace the top part of the container, and duck tape the whole thing closed. You want to make sure it’s completely sealed, so that the greenhouse effect will work. I also like to label and date my containers, but make sure you use a paint pen instead of a Sharpie. I did mine in Sharpie last year, and it bled right off.
Finally, set the whole shebang outside and let it percolate until spring! Do you winter sow? I’d love to hear what crops work for you!
