Winter Sowing 101

You know that time of year.

The daylight hours are short. You pass the furnace multiple times a day, resisting the urge to turn it up a few degrees. The once lush, green garden is now covered in a frosty sheet of snow, destined to remain as such for at least a couple more months.

All I want to do when I’m feeling this way is to get some dirt under my fingernails. But the issues are 1) the ground is frozen solid where I’m at and a plane ticket to Hawaii is just right out of the budget, and 2) even if I were to start some seeds indoors right now, they would be monstrous and unhealthy by the time the weather straightened up for them to go outside. 

But hey, guess what?? I discovered an alternative called winter sowing. 

What is winter sowing?

Simply speaking, winter sowing is a nifty little way to recreate a greenhouse effect by using old milk jugs and other plastic containers. It’s as easy as throwing some seeds in with some potting soil, sticking it out in the winter elements and waiting for mother nature and the seeds to come to an agreement. 

Keep reading below to go into more detail on how to get a head start on your own seeds!

Why should I winter sow?

There are so many reasons why winter sowing is the best thing about winter. Here are the main reasons why I like to winter sow as many seeds as I can:

1. Reusing old plastic containers that may otherwise just get tossed. 
2. The only energy source required is the sun-no use of spendy grow lights!
3. No need to harden off your seedlings before planting them out in your garden. 
4. Saves valuable indoor seed starting space. There are some seeds like tomatoes I prefer to start inside. But since I can start most of my seeds by winter sowing, that just means I can use that indoor space for other things!
5. It barely requires any work. Seriously. 

How to Winter Sow

Intrigued yet?

To begin, you’ll need to start collecting milk jug containers like a lunatic. I’m talking the opaque plastic ones with the screw top lid, not the cardboard-type. Or, really any plastic container with a clear fitting lid will work. I really had to search in my house, but I ended up finding an empty swiffer wet mop box and a cranberry juice bottle. 

You can plant your seeds directly in the plastic container, or you can use something like toilet paper tubes and nest them inside the container. I prefer planting directly in the container. I feel like I have better luck keeping the moisture levels even. 

If you plant directly in the container, be sure to poke some drainage holes in the bottom. Unscrew the top lid to allow ventilation and moisture to enter. If you are using a container with a lid like my swiffer box, go ahead and poke holes on top as well. Allowing the snow and rain to enter is a crucial part of winter sowing success.

Using an Xacto knife and being very careful, cut the bottle or jug almost all the way around, leaving a tiny little section attached to act as a hinge. 

Fill the bottom section about ¾ full with soil. I like to use a mix of organic potting soil and compost. 

Plant your seeds according to the package recommendations, which is typically planting them at twice the depth as the seed is big. For really tiny seeds like onion, scatter the seeds on top, then just scatter some more soil on top of them and gently pat them down. 

If your soil is especially dry, this is a good time to moisten it a bit before duct taping your container closed. If you are planning on winter sowing a bunch of seeds, you may want to write their name inside the container so you don’t mix up your varieties! I used packing tape to adhere the label to the lid of my container. 

Now, go stick your container somewhere they will be exposed to the elements! I place mine on my uncovered porch, where they will have protection from the strong winter winds we get here in Colorado, but they’ll be hit with rain and sun and snow as well.

After a few months, mother nature and your seeds may have come to an agreement that the timing is perfect for germination to begin. Once the rise and fall of temperatures is just right, and the daylight hours are adequate, your seeds will know what to do. 

After this point, you’ll need to keep an eye on them during especially hot or cold days and nights. If your seeds have germinated and then you get a freak cold spell, it might benefit them to have a blanket thrown over them to insulate a little better. Or, on the contrary, if a hot spell comes through, take off the duct tape for a while and let them soak up some of that glorious sunshine without baking in your mini greenhouse. 

Once your garden soil is workable, your seedlings can be gently separated and planted into your garden, no hardening off necessary!

To summarize, winter sowing is AWESOME. 

It’s a hands off, low tech, set it and forget it type of method. It’s especially great for perennial and hardy annual varieties. It allows me to start my summer garden in December, which is a very welcome activity when the months are so cold and long.

Have I convinced you to winter sow this year? What are you planning on growing? Drop me a comment below!

I’ll keep you updated on my own winter sowing adventures!