Winter Sowing – A Step By Step Guide

Share on Google+
Winter Sowing Seeds - A Step By Step Guide

Winter sowing is an easy way to start seeds outside during the winter. Seeds are sown in miniature greenhouses made from recycled plastic containers, and then put outside in the snow and freezing cold. The rest of the work is left to Mother Nature. Once the weather starts to warm in the spring, the seeds will germinate at their own pace, just as in nature.

Since the winter sown containers go outside, they don’t take up space in the house. With winter sowing, there’s no need to sterilize seedling flats and trays, you don’t need any special equipment (like lights or heat mats), there’s no risk of the seedlings damping off, and no need to harden them off. Plus, winter sown seedlings are hardier and more robust than seeds sown indoors, which means they have a much higher survival rate.

How To Winter Sow Seeds

  • Choose the winter sowing containers - Winter sowing containers can be made out of items you throw out every day; containers like milk jugs, 2 liter bottles, restaurant/deli/bakery food containers, ice cream buckets…etc. The shape and size of the container doesn’t matter, but it must be made of transparent plastic, deep enough to allow for 2-3 inches of soil in the bottom, and tall enough to allow a few inches of headspace for the seedlings to grow. See my posts Containers for Winter Sowing Seeds or More Containers for Winter Sowing Seeds for more information.
Winter sowing container options
Winter sowing container options
  • Prepare the containers – To prepare the containers for winter sowing seeds, you will first want to clean the containers. If you’re using a tall narrow container like a 2 ltr bottle or milk jug, you’ll need to cut the container in half as well. Next, poke holes in the top and bottom of the container. Heating a knife and melting the holes makes this task easier (use an old knife because it will turn black over time and have plastic residue on it), otherwise you can use a drill or something sharp to poke the holes. Poke enough holes in the bottom of the container to allow the water to drain so the seeds won’t drown. Add the same amount of holes in the top of the container (if you use milk jugs or 2 ltr bottles, simply leave the caps off rather than poking holes). The holes in the top are there to vent the containers so they won’t overheat, and also to allow rain and moisture to enter the containers.
How to prepare winter sowing containers
How to prepare winter sowing containers
  • Add soil to the container - Regular potting soil can be used for winter sowing seeds. I’ve also used the seed starting soil mix that is specifically made for starting seeds, but it’s a little more expensive. Just make sure you don’t go super cheap on the potting soil. Cheap dirt is too heavy and the seeds will have a hard time germinating, or may end up rotting. Always use fresh, sterile soil when starting seeds; and never, never use soil from your garden in any of your winter sowing containers.
  • Sow the seeds – The best types of seeds to use for winter sowing are the seeds of cold hardy annuals, herbs and vegetables, or plants that are perennial in your zone. If you’re unsure, check the seed packet. Look for terms like “self sowing”, “direct sow outside in the fall”, “direct sow outside in early spring” or “cold stratification”… keywords like these are good indicators of seeds that will work well for winter sowing. The number of seeds you add to each container is up to you, but I prefer to space them out a bit to make it easier to separate the seedlings for planting.
Winter sowing seeds
Winter sowing seeds
  • Label the containers – There are a few ways you could label winter sowing containers. Some people use masking or duct tape to label their containers, and others write directly on the top of the container. However, if you use pencil or a permanent marker, the writing will eventually fade in the sun. Some people swear that paint pens won’t fade, but I haven’t tested this out yet. If you choose to use tape, put it on the bottom of the container so it won’t fade. My preferred method for labeling winter sowing containers is to use cut up old vinyl mini blinds and write on them with pencil. I push the marker into the soil, and have never had one of them fade. You could also reuse plant markers from bedding plants if you save those.
  • Water the containers – Wet down the potting soil in the winter sown containers thoroughly, and allow them to drain. I give mine a light shower with the sprayer in my kitchen sink because it won’t disrupt the soil. If the soil is really dry, water the container a few times to make sure the soil becomes moist.
Watering the winter sowing containers
Watering the winter sowing containers

 

  • Put the lids on – Putting the lids on your winter sowing containers depends on what type of container you use. If the lid snaps on and fits tight, then you’re done. If you used a tall container that you cut in half (i.e.: milk jug, 2ltr bottle), then you can use tape to attach the lid back onto the container (but leave the caps off). You can tape the lids on any container if the lid doesn’t fit tightly, just make sure you don’t completely cover the transparent parts.
  • Put the container outside – Move your winter sown container outside in a spot where they are protected from heavy wind, but will get enough moisture and full sun. If you have pets or children, put the winter sown containers on a table or other spot where they will be out of reach.
  • Forget about them – Once the winter sown seed containers are moved outside, you can pretty much forget about them until early spring. Don’t worry, it’s even ok if they’re covered by snow for a few months.
Winter sown seed containers under snow

Once the weather starts to warm up, check your winter sown containers regularly for any signs of growth. Cold weather plants will start to germinate first, things like broccoli, lettuce, spinach and spring blooming perennials.

The only maintenance you have to do at this point is to make sure they don’t overheat, and make sure the soil doesn’t dry out. Once the seedlings get tall enough where they are touching the top of the inside of the container, it’s time to remove the lids. Winter sown seedlings can dry out pretty quickly once you take the lids off, so check them at least once a day and water if necessary. Once the lids are off, keep an eye on the weather report. If there is a chance of frost, cover the containers with a sheet or blanket overnight.

Winter sown seedlings ready to plant
Winter sown seedlings ready to plant

 

More reading about winter sowing seeds:

Winter Sowing Q&A – Getting Started
Winter Sowing Q&A – Winter Maintenance
Winter Sowing Q&A – Early Spring
Winter Sowing FAQ – Spring
Containers for Winter Sowing Seeds
More Containers for Winter Sowing Seeds
Winter Sowing During a Mild Winter
Cleaning Winter Sowing Containers

Other resources:
wintersown.org
Garden Web Winter Sowing Forum



affiliateDisclosure

 

Comments

  1. says

    I was so excited to read this post! Wish I would've read the part about using old knives yesterday! I like your idea about using the cut up blinds here. If the containers get covered with snow should I just leave them alone? I am still a bit uncertain as to which seeds are okay to start with this method. I tried sorting my seeds out to figure which ones I can winter sow. How about Datura

  2. says

    Hi Julie,
    Thanks, I'm glad you like my post!

    Yes, it's fine if the containers get covered by snow.

    As for which seeds to use, check the package. If they say anything about "self sowing", "direct sow outside in the fall", "direct sow outside in early spring", "cold stratification"… keywords like this are good indicators

  3. Paul says

    That's a great post Amy; it was very informative and well-composed. Now I understand why we've saved a pile of stuff that normally would go in the recycling or garbage!

  4. Paul says

    I thought of a couple questions.

    1. The first question has to do with timing. I'm the vegetable-garden-guy part of our gardening team. I'd like to try starting some vegetables from seed that I would normally buy as seedlings. Specifically, I'd like to try tomatos, broccoli, cauliflower, cabbage, and a variety of peppers. I'd be nervous using the winter sowing

  5. says

    Amy~
    I have a question about Coleus seeds. I'm pretty sure they are too sensitive for winter sowing so how do you recommend I start them? Indoors in a sunny window? Outdoors after last frost? My plan is to have them in pots for the summer and them I'll take cuttings for next year. Thanks again for your excellent guidance!

  6. says

    Hi Paul,
    Thanks for your nice comments. I'm glad you could think of some questions to ask…

    1. You can start both tomatoes and peppers with this method. They will both do fine, but if you want to be safe, you can try some of them with this method and the rest with your usual method and see what you like best. As you said, the broccoli, cauliflower and cabbage will do great

  7. says

    Hi Julie,
    Coleus are very easy to start in a sunny window in your house. They don't require any special seedling care and won't become leggy inside. You can also use the winter sowing method in early spring (April/May) or sow them directly into your pot outside in May. They are very easy to grow from seed.

    Amy

  8. says

    Hi Amy:
    I've been starting seeds in-doors for a couple years now using an aquarium. This method is something I would love to try with vegetables. I started my Tomatoes and Peppers last week in-doors and since I'm running out of room and lighting I think this would be a great experiment for me to try with the remainder of my vegetable seeds since the garden keeps getting bigger and

  9. says

    Hi FranksGreenGirl!
    I know what you mean about running out of room quickly when you start your seeds indoors. I am so happy that I discovered winter sowing! For the last few years, I have been starting seeds indoors as well as winter sowing. This year, I jumped in with both feet and am winter sowing all of my seeds…none inside for me this year!

    No, it's definitely not too

  10. says

    Amy – ready to try the winter sowing! My question is, how many seed do I put into one of the containers? My containers are 6 x 6. Think I will give the ice cream buckets a try as well. Thoughts? Thanks! Theresa

  11. says

    Hi Theresa! Glad to hear you're going to try winter sowing, how exciting! I usually try to space my seeds about an inch apart in the containers. Sometimes I squeeze them in closer if I have a few seeds left over. Take a look at the second picture on this blog post of mine, you'll see the spacing of the peas I sowed in one of my containers…

  12. says

    You have no idea how excited I am that I found your blog posts on winter sowing. I bought seeds today and will start my "sowing" project this week.

  13. says

    So, I have a couple of silly questions! I apologize for their ridiculousness–I'm originally a city girl, and my gardening attempts have not gone well, but I really would like to get growing!

    1) Would "afternoon" as opposed to morning sun be ok, as long as it isn't full sun? Our house doesn't really get much direct morning sun (hill, forest, etc.), but there is

    • says

      Hi, great questions (and totally not ridiculous)!

      1) Yes, as long as you keep them out of the intense afternoon sun. You won't have to worry about this too much until it starts to get warmer.

      2) You don't have to worry about this until after the seeds have sprouted, and you've taken the tops off of the containers. If you can't get the tops back on because

  14. Colleen says

    This will be my first time winter sowing as I had never heard of it before. My tomatoes actually do it on their own in my garden, as I've had quite a few volunteers the last couple years, so I guess I have been doing it without knowing it. I am looking forward to trying it here in southwest Ohio.

  15. says

    I am an avid gardener and just love to grow veggies. We supplement our food bill by growing as much as possible. Having moved from our house to a flat with a garden has it`s problems but we always had too much before. In the summer we had so much that we used to give to all the neighbours. The trouble was that even they could not use the quick enough. Now is still OK as we have just enough

    • says

      The containers protect them so the seeds won't wash away or be eaten by birds and other animals. Also, the containers act like mini greenhouses, which means the seeds will sprout much earlier than they would in the ground, and the containers protect the seedlings from rain/wind/pests. Plus, it's fun! :-)

      Amy

    • says

      Hi Eddie,
      Thanks, glad you like the post. Some people make a ritual of it and start winter sowing on the winter solstice. But I usually start sometime in January or February, whenever I have time to get started. I'm in Minnesota, so if you live in a warmer climate, you can start earlier. But don't start until the evening temperatures are consistently below freezing, or you may get

  16. says

    Amy, Great post! I have been winter sowing the past few years in zone 8b. We have to be very careful here not to start the seeds too early. Our weather goes from 80 to 30 sometimes in a couple of days and can freeze plants that are too far along. May I use your post and photos for a presentation to after school students and the local Home and Garden show?
    Alice – Master Gardener

    • says

      Hi Alice! Thanks for the nice comment about my post. Sure, you can use my post and photos in the presentation, but please make sure that you cite me and this website as your source for both the photos and the text.

      Thanks,
      Amy

  17. says

    Great post :-) My question is how many seeds to put in each container? Also how do you separate them when you are ready to plant without doing to much damage to the roots?

    Thanks ;-)

    • says

      The amount of seeds you sow in each container depends on the type or seed and your preference. Some people like to sow seeds really thick, others like to sow only a few seeds per container. The thicker you sow the seeds, the harder they can be to separate for planting. I personally prefer to sow the seeds farther apart so they are easier to separate.

      To separate the seedlings, I find

    • Anonymous says

      Amy,
      First of all, thank you so much for this new technique. the only question I have is : when you moisten the soil and then put it outside in winter condition, it turns into icy clump with the seeds in it. Won't it hurt them?

      Would be very grateful for your answer

      Larisa

    • says

      Larisa, this method works just like in nature. The seeds in the ground in our gardens are frozen and buried under all that snow during the winter, and then they germinate in the spring when they're ready. Winter sowing seeds works the same way. The benefits of winter sowing rather than directly sowing the seeds into the garden is that the containers will protect the seeds from being washed

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>