Winter Sowing

Winter Sowing in Recycled Containers A month ago I had never heard of Winter Sowing.

“Planting in winter? I can’t plant outside when there’s three feet of snow! Even if I could get to the dirt, nothing would survive!”

Well, according to Urban Sustainable Living and Casaubon’s Book, it will survive – if you do it right.

What to plant
Some seeds require a period of cold (called ’stratification’) in order to germinate. Often these seeds have a hard protective coating that must be broken by cold before the plant can get out and start growing. Other seeds that are a good bet for winter sowing are those described as “self-sowing” or plants native to your area – after all, they come back every year all by themselves, so the seeds must be able to survive the winter. Surprisingly, tomatoes apparently also do fairly well winter sown.

How to plant
The method recommended at Urban Sustainable Living is to put a couple inches of moist seed-starting soil (not dirt from outside – you can buy your soil, or make it with compost and/or peat moss and vermiculite) in the bottom of a plastic container with a clear or translucent top. This can be a juice jug out of your recycling bin, milk jugs, plastic leftover containers, yogurt tubs (with the top cut out to just a ring and used to hold down a piece of clear plastic) or whatever you have on hand. To use milk jugs and similar small-topped containers, cut them in half a few inches from the bottom on three sides and bend the other side to open them. I’m using some of each type of container – whatever I could lay my hands on. Poke drainage holes in the bottom and a few slits in the top to allow heat to escape on sunny days. Plant your seeds according to packet instructions, put the lid on (tape top to bottom of containers you’ve cut in half), label on the side or bottom, and put the container outside. If condensation shows up soon, you’re doing it right. If you check your containers a couple days later and there is no condensation, then your soil was too dry or the openings in the top were too big. This happened to one of my containers – I had not taped the top and bottom milk jug together well enough and all the moisture had escaped. Oh well, I’ll replant and tape it together better.

Why not just plant in the ground? Well, you can do that too, but containers protect the seeds from pests and from just sitting in water-logged soil and rotting. Also, you can plant a container in your kitchen in the middle of January when your green thumb is itching and just put it outside the door in a howling blizzard. Anything you plant in the ground has to get in before the ground freezes and snow covers your yard.

When you see green
The seeds will start to sprout as spring comes and the weather is warming up – the seeds know what conditions they like, so your brassicas (cabbage, broccoli, kale, etc) and greens will show up before the tomatoes. As the seedlings grow, widen the openings in the top of the container to avoid overheating and remove the lid entirely when the plant gets too tall and starts touching the container.

My experiment
I’ve never done winter sowing before, so although I’m trying it out, I’m not counting on it working perfectly. Seeds started by winter sowing will start growing later than seeds started indoors, and I’m not sure there will be enough time for my winter-sown tomatoes to get big and start producing in our shorter summer season here in Minnesota. So, I’ve planted each type of tomato outside, but also plan to start all my seeds indoors at the usual time in two different ways: using the AeroGarden (a gift from my mom) with a special seed starting insert (I’ll discuss this more in a later post, once I actually start some seed in the AeroGarden), and in small containers on my south-facing window sill (although I’m not sure I’ll have enough space for all of them there). I’ve got garden expansion plans, so I should have enough space, but won’t be terribly disappointed if something fails.

I’ve seen claims that winter sowed plants are hardier and sturdier and less susceptible to damping off, etc. We’ll see. I’ll do my best to keep track of which method is most successful and report back here.