Winter sowing is a fun and 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. Sounds cool, right? It gets better…
Benefits Of Winter Sowing Seeds
For me, the biggest benefit of winter sowing my seeds is space. You see, since the winter sown containers go outside, they don’t take up space in the house. That is HUGE!
But there are lots of other BIG benefits of winter sowing too…
- There’s no need to sterilize seedling trays
- You don’t need to buy any special equipment (like seed starting grow lights or heat mats)
- There’s no risk of the seedlings damping off
- Winter sown seedlings don’t need to be hardened off, they are already growing outside!
Plus, winter sown seedlings are hardier and more robust than seeds sown indoors, which means they have a much higher survival rate.
WOW! Are you ready to try winter seed sowing yet? Great, I will show you how.
Supplies For Winter Sowing
- Winter sowing containers
- Scissors
- Drill or old metal knife
- Potting soil
- Seeds
- Heavy duty tape or duct tape
- Plant tags
- Pencil, permanent marker or paint pen
How To Winter Sow – Step By Step
Step 1: Choose your winter sowing containers – The containers can be made out of items you throw out every day; things 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, be 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.
Read more about how to choose the best containers here… Choosing Winter Sowing Containers
Some options for winter sowing containers
Step 2: Prepare the winter sowing containers – To prepare your containers, you will first want to clean the containers. If you’re using a tall narrow container like a 2 liter bottle or milk jug, you’ll need to cut the container in half using a pair of scissors.
Preparing milk jug for winter seed sowing
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 drainage holes in the bottom of the container to allow the water to drain out 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 liter 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.
Preparing milk jug greenhouse for winter sowing seeds
Step 3: Add soil to the winter sowing container – The best potting soil to use in the containers is all purpose potting soil. I’ve also used the seed starting potting mixes that are specifically made for starting seeds, but those are a little more expensive.
Just make sure you buy a good potting mix to use in your containers – 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.
Plus cheap potting soil could be full of weed seeds. Always use fresh, sterile potting soil when starting seeds; and never, never use soil from your garden in any of your containers.
Step 4: Plant the seeds – The best types of seeds to use for winter sowing are the seeds of cold hardy annuals, herbs and cold crop vegetables, or plants that are perennial in your zone.
If you’re unsure, check the seed packets. 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. If the seeds are sown too thick, they will be difficult to separate once they have grown into seedlings.
Read my post about how to choose the best seeds for winter sowing, a get list of seeds I’ve had success winter sowing.
Planting seeds in winter sowing containers
Step 5: Label your winter sowing containers – When you plant seeds in the dead of winter, you will forget what’s in the containers by spring (trust me on this one!), so you’ll definitely want to label them. There are a few ways you could label your containers. Some people write on masking or duct tape, and others write directly on the top of the container.
However, if you use pencil or a permanent marker on top of the containers, the writing will eventually fade in the sun, and could be unreadable by spring. I recommend using a paint pen for writing on the tops of your containers.If you choose to use tape, put it on the bottom of the container so the writing won’t fade in the sun.
My preferred method for labeling my containers is to use plastic plant markers (or make my own using cut up old vinyl mini blinds) and writing on them with pencil. Then I push the marker into the soil, and have never had one of them fade.
Step 6: Water the seeds – After you’re done planting seeds in your containers, water the potting soil thoroughly, and allow the containers to drain before moving them outside.
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 is evenly moist.
Watering seeds after winter sowing in milk jugs
Step 7: Put the lids on the containers – Putting the lids on your 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, 2 liter bottle), then you can use duct tape (or other heavy duty 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 of the container, or the holes you made way back in step 2.
Step 8: Put the winter sown containers outside – Move your containers outside to a spot where they are protected from heavy wind, but will get moisture and full sun. If you have pets or children, put the containers on a table or other spot where they will be out of reach.
Step 9: Forget about them until spring – Once your winter sown seed containers are moved outside, you can pretty much forget about them until early spring. Don’t worry, it’s OK if they’re completely covered by snow for a few months. Leave them be.
Winter sown seeds outdoors
Winter Sowing Maintenance
Once the weather starts to warm up in the spring, check your winter sown containers regularly for any signs of seedlings. Hardy plants will start to germinate first, cold crop vegetables like broccoli, lettuce, spinach and spring blooming perennials.
Plants From Winter Sown Seeds
The only maintenance you have to do in the spring is to make sure the winter sown containers don’t overheat, and that the soil doesn’t dry out. Those mini greenhouses can get pretty hot inside in the sun, so you may need to vent them more. 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 for freezing temperatures, cover the containers with a sheet or blanket overnight.
Next Steps: If you want more help learning how to winter sow, pick up a copy of my Winter Sowing eBook. It’s jam-packed with tips and tricks based on my experience with starting seeds outside during the winter. It will be your essential winter sowing guide that will walk you through every step of the process in detail. Download your copy now!
If you want to learn how to easily grow all of your plants from seeds, then my Online Seed Starting Course would be perfect for you! It is an in-depth online training that will walk you through everything you need to know about growing seeds step-by-step, so you can save tons of money by growing all of your own seeds year after year! Enroll in the course and get started today!
Products I Recommend
More Reading About Winter Sowing
- Winter Sowing eBook – A Comprehensive Guide To Winter Sowing
- How To Choose The Best Seeds For Winter Sowing
- Winter Sowing FAQs – Winter Maintenance
- Winter Sowing During a Mild Winter
- Winter Sowing Seeds On The Winter Solstice
Other Winter Sowing Resources
- wintersown.org (THE official website started by the woman who invented winter sowing!)
- Garden Web WS Forum
Have you ever tried winter sowing yet? Share your tips in the comments section below.
Julie 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
Amy 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
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!
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
Julie 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!
Amy 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
Amy 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
FranksGreenGirl 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
Army Mom 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
Amy - Get Busy Gardening 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.
Sue 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.
Amy Andrychowicz says
Yeah!! Good luck and feel free to ask my any questions.
Amy
jsfox 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.)
Amy Andrychowicz says
Hi, great question (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.
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.
Amy Andrychowicz says
Great, glad to hear you're going to give it a try. Good luck!
promethios 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
Amy Andrychowicz says
Great, hope it works well for you! Good luck with your new garden.
Amy
skimohr says
Why not just directly sow them in late fall where you want them to grow?
Amy Andrychowicz 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 that winter sown 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
Eddie Llewellyn says
Hey! Great post by the way loved it 🙂 My only question is when would be a good general start date for putting the containers outside?
Amy Andrychowicz 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 (zone 4), so if you live in a warmer climate, you can start earlier. But don't start until the evening temperatures are consistently below freezing.
Alice Marty 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. Alice – Master Gardener
Amy Andrychowicz says
Hi Alice! Thanks for the nice comment about my post.
PopRocks 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 😉
Amy Andrychowicz says
The number of seeds you winter 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.
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
Amy Andrychowicz 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 away when it rains or bothered by pests.
Mike the Gardener says
Great post! Very thorough. I love growing all kinds of things in the cooler temperatures.
Amy Andrychowicz says
Thank you!
Becky says
Isn’t it amazing that something as simple as a plastic milk jug can serve as a mini greenhouse? Love it! I hope everyone who reads this will give it a try. Great tips.
Amy Andrychowicz says
Yes, it is amazing and lots of fun! I hope everyone will give it a try too.
Amy
Mariana says
Hello,
Thank you so much for this post! I’m so excited to give this a try! Just wanted to ask a question though… is there a temperature that is too cold for winter sowing? I live in Canada and it can get down to -40 with the wind chill around these parts (never colder though). I see you live in MN; I imagine it gets that cold down there too, but wanted to check 🙂
Thanks again; I’m going to start it this week!
Amy Andrychowicz says
Yes, it can get down to about -20F or -30F during harsh winters. It’s all about the seeds you use. Perennials or anything that seeds itself in your climate will work great. I usually wait until late January or Feb to start winter sowing my cold weather vegetables, that way they won’t be in the deep freeze for quite as long.
April Matt says
We live in PA. Can we start winter sewing now or is it too late?
Amy Andrychowicz says
You can start now, it should still work.
Mariana says
Thank you so much Amy! I’ve collected a bunch of transparent containers; tomorrow I’m off to buy some seed starting soil and going to give it a try. Can’t wait! It seems too good to be true 🙂
Amy Andrychowicz says
Awesome, hope it works great for you!!
Mariana says
Thanks 🙂
Renee says
Would an adoption of this method work for early spring sowing? I’m in Wisconsin, and would like to get a jump-start on my seedlings. What do you think the outcome would be if I planted seeds now (mid-March) in my raised garden, then put the salad container over the seeds to act like a greenhouse?
Amy Andrychowicz says
I think that would work great. If it gets really cold again after the seeds start sprouting, you could always toss a blanket over the top of the containers to keep them warm overnight. Good luck!
Marina Wilson says
Great ideas and I’m desperate to begin as its Dec tomorrow and I’m already getting withdrawal symptoms from gardening. Here in North Uk, we have a lot of rain, strong winds throughout from now until April and sometimes frost on and off for between now and May. I’m going to be using gallon water bottles, square ones and they have a cap. Do I leave the cap off all the time? Or would I put it back on when it’s heavy rain for several days forecast just to protect them?
Amy Andrychowicz says
I know what you mean, I’m already going through withdrawals too! 🙂 Haha! It’s best to leave the caps off of the water jugs for ventilation. As long as the opening is small, they won’t get washed away from the rain.
Marisa says
These are great tips! I need to share this with my friends up north stuck in all this snow! Thanks for sharing!
Amy Andrychowicz says
Yes you totally should, they will love it!! (it’s snowing here today, and it makes me want to get out my containers and start sowing! LOL!)
Sophie says
Can I also sow echeveria and sepervivum seeds in the same way?
Amy Andrychowicz says
If they are cold hardy plants, then the winter sowing method could work for them. I’ve never tried it using those seeds before. I would definitely test it out with a few seeds to see if it works, rather than using all of your seeds for this method.