A Guide to Winter Sowing {Starting Seeds in Winter}

Winter sowing involves sowing the seeds outdoors in miniature greenhouses during the winter, allowing them to germinate naturally in spring.

A drawing of seeds planted in a milk jug.

Results of a recent social media poll showed that 96% of people who start their plants from seed do so by following the instructions on the back of the packet. They sow seeds in pots in sunny windows 6-8 weeks before the last frost. It makes sense that you would follow the directions, but what if there were an easier and much better way to get those seedlings started?

This guide to winter sowing is like a backstage pass to the magic of gardeningโ€”skip the usual routine and embrace a simpler, more effective way to kickstart your seedlings. With its miniature greenhouses and natural germination, winter sowing adds a touch of homestead wisdom to your gardening journey. Whether you’re a first-time veggie gardener or a seasoned pro, the ease of this method is a game-changer. Grab those milk jugs, make some DIY greenhouses, and let your seeds enjoy a winter wonderland until spring bursts forth. Your future garden will thank you for this stress-free start!

What is Winter Sowing?

The idea behind winter sowing is that you sow the seeds outdoors in miniature greenhouses during the winter, allowing them to germinate naturally during the spring. If you live in a northern climate and have snow, this method works even better because the melt adds all the moisture your seeds need. An added bonus to winter sowing over traditional methods: No period of hardening off plants! My biggest downfalls in seedlings are forgetting to water them or over-watering them and then forgetting to bring them in at night when I’m hardening off the plants. This method is perfect for me.

How to Sow Seeds in Winter

So, how does one winter sow? Easily!  You need a plastic container to put your seeds in. Some things that work well are large plastic jugs (like the ones pretzels come in), 2-liter soda bottles, or clear plastic take-out containers. It will work as long as it will hold 3-4 inches of soil.

My personal favorite is to use milk jugs.  With their shape, you can squeeze a bunch together, and if you save caps/lids, you can regulate watering during heavy spring rains. I will show you how to use a milk jug, but the same rules apply to other containers. First, you need to put drainage holes in the bottom and sides. Being somewhat OCD, I like to do three holes, shaped like a triangle, in each of the four “sections” of the bottom. You also want to place three or four holes about 1/4 – 1/2″ up on the sides. I use the transition of textured plastic to smooth plastic as a guide. There is no set rule for the hole size, but I used a 1/8th drill bit.

Tip: Before drilling holes, fill your container with water and pop it in the freezer or outside until it’s frozen solid. This prevents your container from collapsing when you push the drill bit against it.

After you have all your drain holes in place, you need to make a hinged lid. I used the bottom of my handle as a guide, but with any container, you want your lid to be high enough to allow for 3-4″ of soil. Using a sharp knife and plenty of safety measures, cut across the container, leaving about an inch uncut. This will create a hinge.

My milk jug transformed into a winter sowing greenhouse.

Planting in Your Milk Jug

Once you have your greenhouse made, all you do is prepare the soil and seeds. Add your soil and wet it well. Let it drain out the holes you made until the soil is damp but not soaked. Add your seeds according to the packet as far as depth and spacing (though I fudge the spacing and have typically done okay). When you are done, just duct tape the lid closed, remove the cap, and label the outside of the carton with the plant name. If you are using a container that doesn’t have a cap, make sure to put some holes in the top so rain and snow can enter the container.

Placing Your Mini Greenhouses

Once you have everything planted, it’s time to put on your snow boots and jacket to get your greenhouses to their proper place outdoors. The only considerations for placement are that you want your containers to get rain, so don’t put them where they’re under an overhang, and they will need sunlight come spring, so if you can place them in a sunny place now, you won’t have to move them later. I put them right smack in the middle of the front yard.

Because the milk cartons are white, they hardly show up, and after a snow, no one will know they are there. On that note, if you have small children, you may want to mark the area somehow so no one crushes your greenhouses while building a snowman.

When to Start Your Seeds in Maine

This schedule is based on my Maine growing zone, 5b.

January

  • Perennial Flowers
  • Hardy Annual Flowers
  • Brussels Sprouts

February

  • Spinach
  • Kale
  • Peas
  • Broccoli
  • Thyme
  • Sage
  • Oregano
  • Cilantro

March

  • Lettuce
  • Carrots
  • Basil
  • Parsley
  • Bok Choy
  • Beets

April

  • Tomatoes
  • Onions
  • Peppers

Click Here for zone-specific winter sow planting schedules.

Winter Gardening for Beginners by Lindsey Pylarinos
The Winter Harvest Handbook by Eliot Coleman
The Year-Round Vegetable Gardener by Niki Jabbour

See more milk jug upcycling ideas here, and don’t miss one of our most popular upcycling posts, 22 New Uses for Old Pill Bottles.

Frequently Asked Questions

While winter snow and rain contribute moisture, especially in northern climates, monitoring soil moisture is essential. Water the seeds initially and ensure the soil stays damp but not soaked. In periods of low precipitation, supplemental watering may be necessary.

Winter sowing benefits colder climates, especially when snowfall provides natural moisture. However, it can also be adapted to milder climates with adjustments to planting times and consideration of local weather patterns.

Placing the mini greenhouses in a location that receives rain and sunlight is ideal. However, during severe weather, you can provide additional protection by placing them in a sheltered area or covering them temporarily.

If you’ve found value in this blog post and enjoyed reading it, why not share it with your Pinterest community? Pin the image below and spread the love!

A Pinterest-friendly graphic for winter sowing your seeds.

So what are you waiting for? Don’t wait for the last frost. Don’t spend hours counting backward. Throw some seeds in milk cartons and toss them out in the yard. You’ll thank me in the spring.

Have you tried winter sowing in your garden? Share your favorite plants to winter sow or any tips you’ve discovered along the way. If you’re new to this method, what seeds are you excited to try? Let’s swap stories and seed-sowing wisdom in the comments below!

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165 Comments

  1. This is awesome!!! We are so very busy with two toddlers and this would eliminate so much stress for us. Two questions:
    1) Can we put all seeds outside at the same time, even though the chart shows different months for different plants? I’m thinking it just means when they could possibly begin germinating, but not sure. (we are in northern NH, so possibly a different zone than yours!)
    2) Can we do this with any seeds? We like a variety of veggies!

    2)

    1. Hi fellow New Englander!

      1) You should be safe using the same schedule as I use, since we’re practically neighbors.
      2) You can certainly experiment with different veggies and maybe even fruits. The ones I mentioned are the ones I’ve had success with myself.

  2. i live in NW Georgia. Could I do this? And what and when could I start?

    1. I’ve gotten a lot of questions regarding zone-specific guidelines. I am going to address all of that on Thursday, so be sure to check back.

  3. Does the soil in the carton need to stay damp and be watered occasionally or do you just let it sit and get dry?

    1. Until germination, you don’t need to worry to much. Once the seeds have begun to germinate, you may want to keep an eye on things to make sure they aren’t drying out. The neat thing about this system is that the container maintains a lot of moisture, like a greenhouse.

  4. Make the hinged lid first and then drill through the bottom from the inside while container is sitting on a block of wood. Saves time and trouble with freezing the water.

    Unfortunately, we don’t drink milk nor know anyone who does.

    1. You could use juice containers, take out containers, or even try it with a clear plastic tote or container.

    2. Debra L McLaughlin says:

      You can also use water bottles or soda bottles.

  5. Lisa Samson says:

    I live in NE South Dakota where we are freezing until the end of March, when do you suggest I start here? We don’t plant outside until the middle to the end of May. I really would like to try and plant my own plants but have never done it.

    1. We usually start planting outdoors in the soil around Memorial Day weekend here in Maine. You probably are okay to use the same planting schedule as I do.

  6. I love this idea! One question..we sometimes get really windy days here in Ohio in early spring. Have you had any issues with the containers blowing around? I am trying to envision how I might hold them down. BTW, I love Maine. Was stationed at Brunswick in the early 90’s and my oldest was born there ๐Ÿ™‚

    1. You might want to contain them in a plastic milk carton (you know those black heavy crates) if blowing away is an issue for you. I keep mine in a fairly sheltered area, so I haven’t had a problem.

      Maine is pretty awesome. I moved away for 5 years, but I missed it and came back.

  7. I will try this. Do you put the cap back on the jug? And what about watering?

    1. I leave the cap off so that snow and rain can water the soil. Moisture isn’t really an issue until germination begins and the containers are pretty good at maintaining the moisture levels.

  8. I live in central TX

    1. I’ve gotten a lot of questions regarding zone-specific guidelines. I am going to address all of that on Thursday, so be sure to check back.

  9. is it too late for me? im in northwest florida! like 45 minutes from the beach if that helps but near the alabama line

    1. I’ve gotten a lot of questions regarding zone-specific guidelines. I am going to address all of that on Thursday, so be sure to check back.

    2. Anonymous says:

      In Florida you should be able to sow seeds outdoors all year without a greenhouse or any weather protection.

    3. In the panhandle here, and this time table doesn’t work for us at all. For example, we can grow spinach, kale, chard all winter. Start tomatoes inside early February. Also radishes, peas, and a couple others can go directly in the ground now. Not sure how that translates with this process, but I hope that helps some.

  10. This sounds really neat. I want to container plant tomatoes. Tried last year with store bought plants. Had lots of plant but very few tomatoes.I live in NE WA. Della

  11. Sandy Norris says:

    Excellent! I was looking for a planting project for my granddaughters, this fits the bill. Thank you so much.

    1. You are so welcome Sandy. I hope the granddaughters enjoy it.

  12. I am new with gardens. I live in Vt now so cold season last longer. Can I still use your planting list? Also how many plants in a milk container at a time? Thanks

    1. If you are zone 5, you can follow the same schedule I use. As far as spacing, I follow the directions on the packet. For tiny seeds, I just sprinkle lightly. I’m pretty casual about these things ๐Ÿ™‚

  13. Heather T. says:

    Wow, really, just put them outside? My mind is blown in my way of thinking, and here I just bought a grow light, argh, seriously two days ago! I have been saving milk jugs to use as a cloche to put over the plants once in the garden but wow! Do you do this will all your plants? Also I am in WI and am a 5 as well so this guide should be a great help, not sure 5a or b, does it make a huge difference?

    1. There is only a small difference between 5a and 5b. In fact, until recently they didn’t do As and Bs in the zones.

      I don’t do all my plants this way. I’m lucky enough to have a responsible mom with a fabulous greenhouse. I usually split flats of seedlings with her.

  14. I was wondering if you can put the seeds in your raised bed and just put the tops of the milk containers over them?

    1. If you live further south than me, it might work just fine. You might even want to lay straw around the carton to keep the soil warmer.

  15. Margie Closson says:

    How many seeds do you start with?

    1. I’ve gotten a lot of questions regarding zone-specific guidelines. I am going to address all of that on Thursday, so be sure to check back.

  16. Can I start with any seeds or are there some that I should plant closer to spring? I live in Oregon I think zone 1?

    1. Maybe I’m in zone 7…

      1. Jan Stanley says:

        iI you have a lot of jugs,tape them together, then the wind wonโ€™t get them. Walmart sells these plastic containers that fit under a bed. could you use them for winter planting? They sell. Them for putting sweaters away for summer. Under the bed.

    2. I’ve gotten a lot of questions regarding zone-specific guidelines. I am going to address all of that on Thursday, so be sure to check back.

  17. What about if I live in a place without a lot of snow?

    1. Snow isn’t a requirement. It will work no matter where you live. If you tell me your zone I’ll hunt down some info specific to your area.

      1. I’m zone 9-10. Our weather is so weird. 55ยฐ one day and 85ยฐ the next.

  18. Kattrinka says:

    This is my first year trying this method. I’ve got 11 jugs out ๐Ÿ™‚ I used a heated Philips head screwdriver to poke thru the bottom for drainage holes. I have one question; do you ‘pot up’ the seedlings or wait until they are large enough to set out directly?

    1. I usually leave them right in the container until they are safe to put on the ground. Only a few times did they outgrow the container before it was safe to plant (tall flowers and such) and I just moved them into a clear tote set up the same way.

      1. melanie wevver says:

        do u leave the cap on or off

        1. I leave the cap off to allow rain and snow to water the soil.

  19. Why don’t you just drill all your holes from the inside once you cut the jug open? That seems to me to be much easier than waiting for water to freeze…

    1. You certainly could do that, but I found the fragile plastic shape still collapses, even from the inside.

      1. Ginny Bergman says:

        If you drill through the jug from the inside and into something like a piece of wood for support it should work. Great idea for winter sowing. Thank you.

      2. I was thinking about hinging it first too; only I thought that a scrap of wood (or drilling ‘table’) under it and drilling from the inside out into the drilling scrap wood. That would stop the milk jug caving in and not having to to wait for it to freeze. Freezing is not an option for me as I don’t have the extra freezer space.

        1. Yeah, freezing was no inconvenience here since I can just put them out on the deck and they freeze within an hour.

    2. Brenda Roedl says:

      Just use a soldering gun to make your holes. Works great!

      1. i take a metal BBQ skewer ( like for kabobs) and heat that on the stove it punches the holes much easier..I also heat a knife to cut them.
        a little heat saves alot of work

  20. April Esquivel says:

    What zone is the guide for. In Virginia I would already have tomatos seedlings by April. Typically we get our last frost at Easter.

    1. It appears she’s somewhere between Zones 3-5. I’m also in VA, Zone 7A/B. We could probably start some of her later things now.

      1. Yes, sorry. I went back and added that I am in zone 5. I’ve gotten a lot of questions regarding zone-specific guidelines. I am going to address all of that on Thursday, so be sure to check back.

  21. At some point, after it warms up enough, do you pull them out of the milk carton and put them in the ground?

    1. Yup. You can transplant them in the ground when you normally would without worrying about hardening off. If you’ve got some extra milk cartons laying about, they make great cloches in the event of an unexpected spring frost.

  22. Sharon Faria says:

    I live in the Northeast and it snows a lot. If these get burried in the snow is that ok?

    1. Absolutely! I live in Maine and most years mine are buried under 3’+ of snow (this year is an exception). The neat thing about winter sowing is that the seeds take their cues from nature. As the snow thaws, it waters the soil in the carton. As the temperatures rise, the seeds begin to germinate. It removes human error from the equation.

  23. Once Upon a Time in a Bed of Wildflowers says:

    Seriously brilliant! I have never had any luck with starting seeds indoors either.
    ~ Christine

  24. Sounds like a great idea, I’m thinking of trying this. I do have a couple of questions; will the seed

    1. Hi Norma! It seems your whole comment didn’t post. If you see this, feel free to pepper me with questions. I’m happy to help.

      1. Do I plant all the types of seeds in one month, or different types for each month? Hope I made sense.

  25. I can’t wait to try this Jess! I have so little gardening experience but really want to try to maximize the growing season without an enormous cost. Thank you! Sharing on facebook and pinterest!

    1. It really works out great and I find that my spring is less stressful when my plants are winter sowed. Thanks for sharing with your friends and fans!