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What is Winter Sowing?
Winter Sowing is using plastic milk jugs or other plastic containers, and using them as mini-greenhouses outside in the middle of winter, to sow your seeds. Winter sowing is an easy, simple, inexpensive way to sow seeds.
I have been doing this now for the last 6 years or so, and it has worked so well for me, that I wanted to share this Winter Sowing tutorial in hopes that it works for you too. Because it is SOOOOO EASY!!!!! Sow those seeds, and then forget about them for a few month! Seriously. That is all.
Another reason I love winter sowing, is it allows me to get back into my gardening groove before the weather truly lets me. I don't know about you, but after the holidays are over, I start getting the gardening itch.
Winter sowing allows me to actually begin gardening in the winter, but without really dealing with the nastiness of winter. I plant the seeds indoors, and then just pop them outside and let nature to the rest.
Frugal Seed Starting in Winter
Winter Sowing is also a much more frugal way to start seeds. No need to buy all that seed starting equipment such as heat mats, grow lights, plant trays, etc. Just save your used milk jugs, and then the only thing you need to acquire is the potting soil to grow in, and the seeds! And duct tape.
Winter Sowing Containers or Mini Greenhouses for Winter Sowing:
I like to use milk jugs for my winter sowing containers, but any similar type of container will work. To prepare them, first, poke a bunch of holes in the bottom for drainage, and a few holes around the top for extra air circulation.
I use a Phillips head screwdriver that I heat up over a gas burner, than just poke it thru the plastic a bunch of times. Then you cut the milk jug almost all the way around about 4" up from the bottom, but leaving an inch or so intact below the handle, as a hinge, so that you can lift the upper part of the jug open. I use an X-acto knife to do this.
Which Soil to Use for Winter Sowing
The most important aspect of the soil you choose to use, is to use a soil that drains well. If the soil stays too wet, the seeds may rot. I usually use the same kind of potting soil I talk about in my Seed Starting Equipment post, which is a moisture control potting soil.
You don't need to use the moisture control, it's just what I usually have on hand. If you are purchasing soil specifically for use in winter sowing, I would not choose the moisture control potting soil unless you live in a very dry climate.
How to Plant your Winter Sowing Jugs:
- Fill the bottom part of the jug with 3" of damp potting soil. Moisten the soil before using, by placing some soil in a plastic bin and watering and then mixing the water in well. The soil should hold its shape when squeezed, but not be dripping wet.
- Plant the seeds into the soil as directed on the package for depth of planting. I tend to plant the seeds pretty densely, knowing that I will be dividing up the plants to transplant later in the spring.
- Spray the surface with water so the top 1" or so of soil is quite damp.
- Close the jug and tape the jug closed all the way around.
- You can leave the plastic cap that came with the milk jug on, until the seeds germinate. This will keep the moisture in there, which helps hasten seed germination.
- Once the seeds germinate, remove plastic lid to allow for rain to get in, and the air to circulate out when it gets warm in there.
- Have some duct tape or similar tape on hand, that you will need to seal the two halves of the jug closed.
- Also, stick a label in there also with the name of the seeds you are planning to sow. Don't write on the tape or jug, as the sun will fade it. Ask me how I know!
Where to Place Your Winter Sowing Containers:
Set your Winter Sowing containers outdoors in a sunny location that will receive rain. Do not put under an eave which might prevent rain from entering into the open top.
Caring for your Winter Sowing Containers:
Then, just be watchful of really warm weather. If the seeds have germinated and you get an out of the blue HOT day, the plants may bake in there with the lid still on.
So if you are getting some unseasonably warm weather, take the tape off and open up the lids. You may need to water them also.
If it cools back down, tape them closed again. Then just watch.
Once the plants are big enough to be filling the jugs with their greenery, it is time to pop the tops off like I just mentioned. And transplant as soon as you can for what you have grown.
Winter Sowing Flower Seed, Perennials and Annuals
I like to grow my own perennials and annuals using winter sowing. I tend to start out with hardy perennial seeds first, as early as January and through the month of February.
Then I plant annuals and more tender perennials later in March. Winter sowing flowers & perennials is a great inexpensive way to grow your garden. Save your own seeds, or exchange seed with friends or family and grow your own.
I usually start as early as January with lavender, phlox, rudbeckia, and other similar perennials. I will then do some sweet peas a few weeks later. And a few weeks after that, I will sow snapdragons, marigolds, nastursium, lobelia, alyssum and other annuals.
But this is such a super flexible way of growing, if you haven't started in January, go ahead and sow all the things in late Feb or March! Just remember to keep notes, so next year you can refer back and change up how you do things if you need too.
Winter Sowing Vegetables
I like to start my cold season vegetable crops in February. Some cold season veggies I have winter sown with success, are all the brassicas (kale, broccoli, cauliflower, cabbage, etc), greens such as chard, spinach and lettuce as well as root veggies and onions. Then by late March they should be ready for transplanting.
You could even try some warm weather vegetables like summer squash, winter squash or pumpkins in April. You could also start your cucumbers and melons in April as well. I have not tried warm season crops like tomatoes and peppers using winter sowing, but I bet it would work also.
Winter Sowing Zone 8
I am in gardening zone 8b, and these are winter sowing methods that have worked well for me here in the PNW. Please let me know if you try this growing method and what you plant when!
If you aren't sure what to plant when, I suggest starting a bit of seed, and then 4 weeks later, start another batch. Keep notes and compare what did well when. Then next year, you will have a better idea of what to plant when. I am anxious to hear how you all do!
WinterSowing Results and More Information
Be sure to check out my 2018 Winter Sowing Results article where I share what I grew using winter sowing that year!
For more information on Winter Sowing, check out WinterSown.Org