Winter sowing is fun and easy! In this quick-start guide, I cover everything from the benefits and when to begin, all the way through to maintenance and transplanting. Plus I’ll give you detailed step-by-step instructions to show you exactly how to winter sow your seeds.
If you enjoy growing seeds, then you definitely need to give winter sowing a try. It’s a really fun method to use, and has even been a game-changer for some gardeners.
With the winter sowing method, you put your seeds outside so they don’t take up any space in the house. Plus, you don’t have to buy any expensive equipment, or fuss over tender seedlings for months on end.
There are lots of other benefits too, which I will list out below (I’m getting a bit ahead of myself here). I will also tell you all the details you need to know in order to get started, and give you step-by-step instructions too.
Here’s what you’ll find in this quick-start winter sowing guide…
- What Is Winter Sowing?
- Benefits
- When Can You Start?
- How To Winter Sow
- How Long Do The Seeds Take To Grow?
- Monitoring & Maintaining Your Containers
- Planting The Seedlings Into The Garden
What Is Winter Sowing?
Winter sowing is a fun and easy way to start seeds outside during the winter. You plant your seeds in miniature greenhouses made from recycled plastic containers, and then put them outside in the snow and freezing cold.
Once the weather starts to warm up in the spring, the seeds will germinate at their own pace, just as in nature. Sounds cool, right? It gets better…
Benefits Of Winter Seed Sowing
For me, the biggest benefit of winter sowing is space. Since they go outside, they don’t take up any space in the house. That is HUGE!
But there are lots of other BIG benefits of winter sowing too…
- You don’t need to buy any special equipment or grow lights
- There’s no need to sterilize seedling trays
- There’s no risk of the seedlings damping off
- Winter sown seedlings don’t need to be hardened off, they are already growing outside
- The seedlings are hardier, and more robust, which means they have a much higher survival rate
- You can start planting your seeds much earlier
When Can You Start?
One of the things I love the best about winter sowing is that there is no set schedule you need to worry about. You don’t have to think about your last frost dates, or time your plantings to avoid leggy seedlings.
You can winter sow seeds outdoors at your own convenience, and whenever you have time. The only rule you need to follow is to wait until freezing temperatures are here to stay. Learn exactly when to begin here.
How To Winter Sow Seeds
Winter sowing is easy. There’s no fancy technique, or any complicated equipment setup required. You only need a few supplies to get started.
But, there are are couple of things you need to understand before you begin. So, first let’s talk about the three main things you’ll need… soil, containers, and seeds.
The Best Soil To Use
The best type of soil to use is an all-purpose potting soil. I’ve also used a seed starting potting mix, which works just fine. But those can be a little bit more expensive.
Just make sure you buy a quality potting mix. Cheap dirt is too heavy, and could be full of weed seeds. Also, always use fresh, sterile potting soil, and never, use garden soil in any of your containers. Read about the best soil to use (and which ones to avoid) here.
Filling a milk jug with soil
Choosing Containers
There are tons of different types of containers you can use to make your mini greenhouses for winter sowing. They can be made out of items you throw out every day. Things like milk jugs, 2 liter bottles, restaurant/deli/bakery food storage, ice cream buckets…etc.
The shape and size doesn’t matter, but it must be made of transparent plastic. It should also be deep enough to hold 3-4 inches of soil in the bottom, and tall enough to allow a few inches of headspace for the seedlings to grow. Read all about how to choose the best containers here.
Types Of Seeds To Plant
It’s important to use the correct types of seeds, because you can’t just use anything. The best ones to use for winter sowing are 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. Learn all about how to choose the best seeds to use here.
Step-By-Step Instructions
Before getting started, be sure to clean your containers. You can simply rinse them out if there’s no residue in them. Otherwise, if they’re dirty, then be sure to wash them first. Here’s how to clean your containers.
Supplies Needed:
- Containers
- Scissors
- Drill or old metal knife
- Potting soil
- Seeds
- Heavy duty tape or duct tape
- Plant tags (optional)
- Pencil, permanent marker or paint pen
Step 1: Choose your containers – Raid your recycling bin to find the perfect mini greenhouses, or ask your family and friends to save them for you. It may take some time to build up a good selection, so be sure to start hunting for them a few weeks before you plan to begin winter sowing.
Different types of containers to use for winter sowing
Step 2: Prepare the mini greenhouses – If you’re using a tall, narrow container, like a 2 liter bottle or milk jug, first cut it in half using a pair of scissors. Then poke holes in the bottom for drainage, and also in the top for ventilation. Use a drill to make the holes, or a hot knife to melt them into the plastic. Learn exactly how to prepare winter sowing containers here.
Making drainage holes in milk jug greenhouse
Step 3: Add the soil – Fill the bottom of your mini greenhouse with 3-4 inches of potting soil or a seedling mix. If the soil is really dry, you may want to wet it down a bit before planting the seeds.
Step 4: Plant the seeds – 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 transplant the seedlings later on. If they’re sown too thick, it will be difficult to separate the seedlings.
Planting seeds in winter sowing containers
Step 5: Label your winter sowing – 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 do that. Some people write on masking or duct tape, and others write directly on the top of the container.
However, if you use a permanent marker on top, the writing will fade in the sun, and could be unreadable by spring. I recommend using a paint pen to write on the top. If you use tape, put it on the bottom of the container so the writing won’t fade.
My preferred method for labeling my winter sown seed containers is to use plastic plant markers, and writing on them with a pencil. Then I push the marker into the soil, and I have never had one of them fade.
Step 6: Water the soil – After you’re done planting the seeds, water the soil thoroughly, and allow it 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 or displace the seeds. If the soil is really dry, then water it a few times to make sure it’s evenly moist.
Watering seeds after winter sowing in milk jugs
Step 7: Put the lids on – The details for this step depend on what type of container you used. If the lid snaps on and fits tight, then you’re done.
If you used something tall that you had to cut in half (i.e.: milk jug, 2 liter bottle… etc), then you can use duct tape (or other heavy duty tape) to attach the lid back on (but leave the caps off).
You can tape any of the lids on if they don’t fit tightly. Just make sure you don’t completely cover the transparent parts of the container, or the holes you made back in step 2.
Step 8: Move them outside – Move your winter sown 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 your containers on a table, or other spot where they will be out of reach.
Step 9: Forget about them until spring – Once they’re moved outside, you can pretty much forget about them until spring. Don’t worry, it’s OK if they’re completely covered by snow for a few months. Just leave them be.
Winter sown seeds outside in the snow
How Long Do Winter Sown Seeds Take To Grow?
The seeds will start growing at their own pace, and the timing can be different for each one. Some may start germinating before the snow even melts off the containers. While others won’t start growing until the weather gets warmer in the spring.
On average, my winter sown seeds start germinating in early March… but I’m in Minneapolis zone 4b. Warmer zones will start to see sprouts much earlier. Oh, and it can also vary year to year, depending on the weather.
The best thing to do is to make sure you check regularly for any signs of sprouts. Start checking them as the weather begins to warm up in the late winter/early spring. The hardiest seeds will germinate first.
Winter sown seeds growing in the spring
Monitoring & Maintaining Your Containers
The only maintenance you have to do in the spring is to make sure your seedlings 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. You can vent them by cracking the lids open, or making the holes in the top larger.
Once the seedlings get tall enough that they are touching the top of the inside of the container, it’s time to remove the lids.
The soil 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 your seedlings with a sheet or blanket overnight.
Planting The Seedlings Into The Garden
Once the seedlings are tall enough, and have grown their first few sets of true leaves, it’s time to plant them into the garden. Hardy winter sown seedlings can be transplanted as soon as the soil is workable in early spring.
There’s no need to harden them off either, since they’re already growing outside! You can simply plant them directly into the garden.
Winter sown seedlings ready to transplant into the garden
Winter sowing is a great way to grow the seeds for your garden every year. You can do it at your own pace, and there’s minimal care involved. And, since you don’t have to harden winter sown seedlings, it makes transplanting them a breeze too!
Next Steps: If you want more help learning how to winter sow, pick up a copy of my Winter Sowing eBook. It’ll be your essential guide that will walk you through every step of the process in detail.
If you want learn how to easily grow all of your plants from seeds, then the 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 all types of seeds, step-by-step.
Products I Recommend
More Posts About Winter Sowing
Other Winter Sowing Resources
Have you tried winter sowing yet? Share your tips or experiences in the comments section below.
Julie says
I was so excited to read this post! 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 seeds? Can I do those? Is it safe to assume that all perennials can be winter sown? Thanks again for your excellent post. You’re a great writer!
Amy Andrychowicz says
Thanks so much for your nice words, I’m glad you enjoyed the post! 🙂
Yes, it’s fine if the containers get covered by snow.
Datura seeds would work well, I have had great success with winter sowing those. And you’re safe to assume that all perennials in your growing zone would work. Here’s a detailed post that I wrote that will show you exactly how to figure out which seeds to use… How To Choose The Best Seeds For 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 Andrychowicz says
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. They are very easy to grow from seed.
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 containers that normally would go in the recycling or garbage!
Amy Andrychowicz says
Haha! Thanks so much, glad you enjoyed the post. 🙂
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 tomatoes, broccoli, cauliflower, cabbage, and a variety of peppers. I'd be nervous using the winter sowing technique with the tomatoes and peppers, since they pretty sensitive to cold weather and frost. The others are pretty tough. Do you have a timeline you’d suggest?
2. My second question has to do with containers. I have lots of seed starter trays that have a clear plastic top. Can I use these, or do I have to group-plant them all in one container. I’m thinking it will make transplanting easier if each seed is planted separately, but maybe this technique requires them to be planted together to achieve some ‘thermal mass’. What do you think?
Thanks again for the original post. Any follow-up help would be greatly appreciated.
Amy Andrychowicz says
Great questions!
1. You can winter sow both tomatoes and peppers. They should both do fine. I have tomatoes and peppers reseed themselves in my garden every year. Any seed that self-sows does great with this method. But if you want to be safe, you can try winter sowing some of them, and plant the rest with your usual method to see which you like best. As you said, the broccoli, cauliflower and cabbage will do great, and will be some of the first ones to start growing in the spring. As far a timeline goes… you can start winter sowing as soon as freezing temps are here to stay. I usually start in January here in MN. The seeds are programmed to know when it’s safe for them to germinate.
2. I would not recommend using those little seed starting cells, because they will dry out too fast in the spring. You need at least 3-4″ of soil in the container so it will hold moisture, and retain healthy seedling growth. You could use the trays though, if you can remove the cells and figure out a way to secure the top so it won’t blow away. You will also need to make holes in the top and bottom.
Good luck, and let me know how it goes for you.
FranksGreenGirl says
Hi Amy:
I've been starting seeds in-doors for a couple years now using an aquarium. Winter sowing 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 bigger. I still have to plant my beans and peas, zucchini, lettuce, pumpkin and so forth. I have been a little leery with the warm and now cold weather we are having here in Minnesota. Since it’s March now, would it be too late for me to try this method? Also, I have some Joe Pye Weed and Rosemary that I have been trying to winter sow for the last 3 weeks with this method. I don’t see anything yet, is this normal?
Amy Andrychowicz says
I know what you mean about running out of room quickly when you start seeds indoors! I am so happy that I discovered winter sowing! It sure makes things easier.
It’s definitely not too late for you to start winter sowing your veggies in March. In fact, I’ve been busy sowing seeds in containers for the past few weeks, and will continue into April. I understand the concern to start your veggies when we’re still experiencing freezing and thawing. It sounds funny, but the seeds are kinda programmed to know when it’s safe to start growing. Just keep the lids on the containers, even after your seeds start germinating. If we’re going to have a really cold night, then you can cover them with blankets, or move them into the garage if you want. That will protect the sensitive seedlings from late frost. But all of those veggie seeds you mention are fast growers, so you could certainly hold off a few more weeks before planting them. Or just wait, and direct sow into your garden them once it’s warm enough.
Don’t worry about the seeds you haven’t seen growing yet, I haven’t seen growth in most of my containers yet either. With this warm spring we’ve been having, I suspect you will start to see growth soon. Keep me posted on your progress, and good luck!
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 Andrychowicz 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" sun be ok? Our house doesn't really get much direct sun (hill, forest, etc.), but there is some good afternoon light.
2) In a previous comment, there is suggestion to cover the trays with a blanket in the event of a frost overnight. But, temps are going to be below freezing most nights at this time of year. Would you just tuck them in at night every night, or is this method really meant for later in winter?
Thanks so much!
Amy Andrychowicz says
Hi, great questions (and totally not ridiculous)!
1) Yes, as long as you keep them out of the intense afternoon sun, or ventilate the containers once the seedlings start grow. You won't have to worry about this too much until it starts to get warmer in the spring.
2) You don’t have to worry about covering the trays until after the seeds have germinated in the spring, and you’ve taken the tops off the containers. If you can’t get the tops back on because the seedlings are too tall, then you’ll need to protect the seedlings from extreme freezing temps (normally the tops would protect them).
Good luck, I hope your winter sowing goes well for you!
P.S. I’m a city girl too, LOL!
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
Awesome, glad to hear you're going to give winter sowing a try. Self-sowers are always a great candidate! 🙂 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
You certainly could direct sow them. The benefit of winter sowing is that the containers protect the seeds so they 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 germinate much earlier than they would in the ground. Those mini greenhouses also protect the seedlings from rain/wind/pests. Plus, it's fun! 🙂
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 avid winter sowers make a ritual of beginning on the winter solstice. But I usually start sometime in January or February, whenever I have time. I'm in Minnesota (zone 4b), so if you live in a warmer climate, you may need to start later. Just wait until the evening temperatures are consistently below freezing. Here’s a post I wrote that talks about this in detail… When To Start Winter Sowing Your Seeds.
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
Amy Andrychowicz says
Thanks so much for adding your tip about starting your winter sowing later in zone 8b. It’s always so great to get some input from gardeners in warmer growing zones. When do you usually start?
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
It depends on the type of seed, and your preference. Some people like to sow the seeds really thick, others like to plant only a few seeds per container. The thicker you sow the seeds, the harder the seedlings can be to separate for planting. I personally prefer to sow the seeds farther apart so they are easier to separate. You definitely could damage some of the roots trying to separate crowded seedlings. But, most of the time the rootball is pretty thick by the time you’re ready to transplant them, so it’s not a huge concern. Just be careful as you work to tease the roots apart.
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
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. Also, many of the seeds that work with this method require cold stratification in order to grow. The freezing and thawing does this for us naturally, so we don’t have to worry about it.
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.
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 (that’s without windchill) here in z4b 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 (it’s mid-March) or is it too late?
Amy Andrychowicz says
You can start winter sowing in mid-March, 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 winter sowing 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 growing too early, 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 gardening withdrawals too! 🙂 Haha!
It’s best to always leave the caps off of the water jugs for ventilation. As long as the opening in the jug is small, the seeds won’t be disturbed by the rain.
Marisa says
These are great tips! I need to share this winter sowing technique 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.
juli says
Amy,
I just started winter sowing. Yesterday, I planted cherry tomatoes, beef tomatoes, basil, beetroot and daisies. I’m not quite sure if this is going to work. My husband laughs at me and says I can not plant anything when there is snow. Finding your website gives me hope. Do I have to take them in when snow comes or leave them out?
Amy Andrychowicz says
Haha, don’t listen to him! People laugh at me when I tell them about winter sowing too. 😀 But it works! No, you don’t need to bring your containers inside at all. Just leave them out, and they will be fine even if they’re completely covered by snow! However, the winter sowing method doesn’t work for all types of seeds… so, a few of the ones you planted may not grow (but please don’t feel bad!!). Here’s a list of great seeds to use for winter sowing to help you out.
lucy says
Hi Amy,
I may have missed something in your post – I was thinking of starting seedlings indoors in small pots and transplant outside after the threat of frost/snow is over. Is there a reason you would not start indoors?
Tk you!
Amy Andrychowicz says
Winter sowing is just an alternative method of starting seeds, and works great for certain types of seeds. I still start many other seeds indoors under lights, it depends on the type of seed. Here’s a list of seeds that work great with the winter sowing method… How To Choose The Best Seeds For Winter Sowing. And here’s some info to get you started with growing seeds indoors… Tips For Growing Seeds Indoors For Beginners.
Rosie says
I live in zone 9a. It rarely freezes here. Does it make sense for me to winter sow? I’m thinking it could still be a beneficial way to start seeds outdoors without the drawbacks of indoor seed starting. If so, when should I start (i.e. what conditions)?
Amy Andrychowicz says
Yes, you certainly can still use the winter sowing method to start your seeds outside rather than taking up space in the house. You won’t get the benefit of cold stratification for your seeds though, so you’d still have to do that for seeds the require it. As for when to start… I would plan to winter sow your seeds at the same time as you would start them indoors. Since it rarely gets below freezing where you live, you won’t have to worry about them being started too early. The containers will protect the seedlings from frost.