Winter Sowing

I am fairly new to gardening so I was surprised at how antsy I got after finishing my fall chores. I had been used to going out to check on plants as an excuse to take a walk, be outside, or just do something. Anything. After that last plant was pulled in the fall, I had about two weeks of rest before I started getting anxious to garden again. Of course, what is a bored gardener to do but start planning for next year?

And that’s when I stumbled on winter sowing.

Winter sowing is a method of germinating seeds outside, during the coldest winter months. It is purported to mimic nature. That is, when plants are left to their own devices, they have figured out ways to grow themselves again. One way that perennial plants (in particular) do this is when their flowers die in the fall. The flower heads dry out, the seeds drop to the ground, and then they wait. The seeds are typically just out in the open through the winter (good or bad). Then, when the weather starts to change to their ideal temperatures, a little switch inside the seed clicks and up they pop. Winter sowing takes the natural process of a seed but allows gardeners to protect them against animals or bugs or unusual weather.

Steps for Winter Sowing:

1. Get a container that is opaque or clear. It must be big enough to hold about three or four inches of soil in the bottom. The most popular choice tends to be milk jugs because they are opaque and the right shape. As a bonus, it helps to recycle something that would end up in a landfill! Other options I have seen include vinegar containers, rotisserie chicken containers, water jugs, and even Ziploc bags. Anything that can hold soil and let some light in will probably work.
2. Prepare your container. Drill holes in the bottom for drainage. I also drilled a few in the sides in case the bottom holes get clogged with ice during the winter. If you are using a milk jug, cut the jug almost in half. Leave the handle attached so that it acts like a hinged roof.
3. Get your soil. Pick a regular potting mix but not one with any “moisture retaining” words in the name. That will hold too much water and could cause things to rot in your soil.
4. Moisten the soil. Put some soil in a bucket and add water. Mix it up until it is a damp consistency. When you pick up a handful and squeeze it, it should hold it’s shape but water shouldn’t drip out. If it is too wet, drain some of the water and add more soil. If it’s too dry, add some water.
5. Fill your container with soil. I put a coffee filter at the bottom of my containers so dirt doesn’t spill out. Fill it up about three or four inches.
6. Sow your seeds. According to the advocates for winter sowing, all seeds are fair game except for tropical seeds. There is likely most success with native perennials since you will be mimicking their natural environment. (More about this plus link.)
7. Label those containers! Use whatever you can find to label those containers. All of the moisture and weather outside is likely to wash things away so either use something really tough (nail polish painted on, a garden pen, etc.), label multiple times, or both. I labeled a garden marker, wrote all over the container, and also kept a list of what I sowed in each numbered container. I also made little beaded labels out of old Montessori counting beads and attached them to the handles.
8. Close your container and tape it up. Tape all the way around the cut part of your container so it is all closed up.
9. Remove your lids. You should take off the milk jug lids in order to let in rain, snow, and weather throughout the winter. It also allows for air circulation when it starts to get warmer. If you are using other containers, make sure there are holes in the top for the same reason.
10. Place your containers outside. Take the whole contraption outside to a protected area (protected against dogs who might chew on them, wind that might blow them over, etc.). There are mixed messages about whether you should put them in the shade or the sun. I placed mine in the shade for now because I do not want them getting tricked by any early warmth, germinating, and then getting killed in a sudden frost. I will move them to a place with morning sun once it gets closer to spring.
11. Have a cup of tea. After you have bid goodnight to your little containers, go back inside and have a cup of tea or a cup of something warm. They will happily sleep through the winter and start to perk up when the weather starts to improve.

For the most part, the weather should do what it does and the seeds will benefit from that. Seedlings do not need to be hardened off (like you would have to do with indoor started seedlings) which helps to produce hardier seedlings. Keep an eye on moisture level and give them some spritzes of water if their soil appears dry or it has been awhile since it’s rained or snowed. Last year, I took the idea that you “just ignore them” too seriously, didn’t do anything with my jugs, and everything dried out and died. If they are drying out too often, it might be helpful to move the jugs to a shadier location. Direct sun might dry out dirt quicker than being in the shade. Smaller containers may also dry out quicker than larger ones.

In the spring, the seedlings will start to emerge. I think you open the container when it starts to get warm in order to give them some air. Once the soil is workable and the seedlings have a few sets of true leaves, transplant them to their permanent spot. I’ll have to see how it works this year and write more about the spring process. For now, though, it gives me something to do during the long winter months. The only problem is how many seeds I’ve now ordered from the seed catalogs in order to try this method! I need to get planning for where I’ll put all of these plants!