I love starting seeds indoors. It’s a great way to get a jump start on the season – to play in the soil even when the temperatures outdoors are sub-freezing. Growing seedlings indoors can be a little tricky though. Plus, those seed trays take up space that not all homeowners are fortunate to have. It was space limitations which led one gardener to get creative and find a different solution. Her approach is the subject of today’s podcast; winter sowing, a simple way to successfully start seeds outdoors.
Trudy Davidoff was a novice seed starter who was challenged for space. Her small cottage in New York didn’t provide the room she needed to accommodate seed trays. After a little research, Trudy learned that many varieties of seeds require a chill period to trigger germination. So, she decided to try to mimic what happens naturally.
She sowed seeds in containers in late winter, left the containers outdoors and waited to see if they would germinate in the spring. Without supplemental water, fertilizer or special coddling; the seeds did germinate, and as the temperatures rose so did Trudy’s seedlings.
Flash forward a couple of decades, and Trudy’s methods are becoming more popular. What’s not to love? After all, some of the best tools for winter sowing are repurposed materials you already have in your home, and winter sowing couldn’t be much easier. Once the seeds are in the growing medium, you can practically forget about them until they are ready to transplant into your garden beds.
Winter Sowing Benefits
Gardening can be an expensive hobby. It doesn’t need to be, and starting your own plants from seed is a great way to save money. Well, winter seed sowing is about as low cost as it gets. The only thing you really need to invest in is the soil, but that won’t set you back much either.
There are lots of seed exchange groups where you can get seeds for free or for very little cost. Even if you purchase seeds, the cost of a couple of dollars is so worth the payoff. You can buy packets of seed just about everywhere these days, but this is another example of “you get what you pay for.” Quality matters – not just in how many seeds will germinate but it can also play a role in how healthy your mature plants will be.
I recommend looking for organic seeds. Whether you get them from an exchange or you spend an extra dollar to purchase organic seeds, the plants you grow will be healthier as a result of their parent plant not having been treated with or exposed to chemicals.
Great container options for winter sowing are items you’ve already got around the house – like milk jugs, take out food containers, and other large plastic containers with deep bottoms and clear tops. You probably have duct tape and a marker on hand too.
Here’s what you won’t need for winter sowing: special lights, heat mats or fans. This method is a sort of “tough love” approach to seed starting, but it’s really just mimicking the natural process. It saves you money on your power bill too.
Starting seeds indoors can require a lot of extra equipment. In my seed-starting room, I invest in quality lighting, fans, germination heat mats and more.
Another avoidable but common problem to seedlings started indoors: they are at risk for developing a fungal disease known as “damping off.” It kills seedlings at the soil surface – usually as a result of inadequate air circulation. With winter sowing, that’s not a problem.
Winter sowing is also a time-saver. Since seedlings will be growing under natural light and temperature conditions, you won’t need to invest time in hardening them off before they go into your garden beds. They will already be acclimated, and they’ll be hardier and stocker than if they are grown indoors without sufficient light.
I love starting seeds indoors, but the hardening off process can be time-consuming.
The process of hardening off is time-consuming. it takes about 7-10 days to gradually acclimate your indoor-grown seedlings to full sun. In my case, that’s hand moving about 68 full trays of seedlings in and out every single day during the hardening off process.
I’ll admit, in spite of the extra work, I prefer starting seeds indoors. I like the hands-on care they require and being able to watch as they emerge from the soil and mature into new plants bursting with life. There’s something about observing the daily miracle of growth that I never get tired of. That said, if you’re the type of gardener who would prefer to sow it and forget it, winter sowing is right up your alley.
If you haven’t tried it before, you might worry about your seeds freezing. Don’t. In nature, seeds freeze all the time. Freezing actually prolongs the life of seeds, and some types require a freeze (or very cold temperatures) in order to germinate at all.
What you need to watch for instead is sowing seeds too early in the winter months. If a short, early warm spell comes along; the seeds could germinate too soon. Then when the temperatures plummet again, the young seedlings won’t be mature enough to power through. For those of us living in the Northern Hemisphere, a good rule of thumb is to wait until around Christmas before we start our winter sowing.
What to Sow
There are so many varieties of seeds that are great candidates for winter sowing. Edible cool-season crops, flowering plants, herbs – you have a lot of options to choose from when you’re ready to give this method a try.
Let’s start with perennials. The first quality you should look for when determining if a seed variety is a good winter sowing candidate is the hardiness zone that is appropriate for the perennial plant you’re considering. If it’s naturally hardy in your zone, odds are good that it’s a good option for winter sowing.
Check the seed packet. If there is any mention that the seeds need to be stratified or scarified, that’s another good indicator of a seed type that will respond well to winter sowing.
In general, seeds require some sort of trigger to break their dormancy and cause germination. Stratification is the process of using prolonged periods of cold temperatures to break dormancy.
Consider what happens in nature. Certain varieties of seed fall to the ground and have to ride out winter before they sprout. If they germinated immediately after they made contact with the soil, they wouldn’t survive the winter season.
It’s only after a certain period of time in cool or freezing temperatures that they become ready to germinate. This process can be mimicked by placing the seeds into a refrigerator or a freezer, but winter sowing eliminates the need for that. The seeds are exposed to the cold temperatures of the natural environment and break dormancy as the days grow longer and the soil becomes warmer.
Milkweed is a great example. It’s tricky to get milkweed seeds to germinate unless you provide the proper chill period. So, winter sowing is a much easier solution for providing the conditions milkweed needs.
Milkweed (aka butterfly weed) is a good example of a perennial that self-sows its seeds in fall. The chilling time is necessary for spring germination. It’s also a great candidate for winter sowing. These milkweed seeds are ready to take flight, likely with the next gust of wind. Their feathery tails can keep them airborne for great distances before settling back onto soil.
The term scarification is another signal of a good winter sowing option. Lots of seed varieties have a hard outer coating designed to protect the seed embryo. In nature, those hard shells are broken down in a variety of ways – including the digestive system of birds or other creatures, as well as freezing temperatures.
Scarification is the process of manually weakening the hard seed coating. This can be done in many ways, but with winter sowing, it’s unnecessary. The freezing temperatures can weaken the seed coat naturally.
Other terms to look for in seed varieties you are interested in winter sowing:
- self-sowing
- direct-sowing
- cold-hardy
- pre-chill
- sown when cool
When you spot those on a seed packet or in a seed description, you can feel confident about trying the winter sowing technique.
The varietal name can also provide clues about their winter sowing viability. Alpine, polar, Siberian, oriental, arctic – notice a trend? Those varieties were so named, because of their native climate or their ability to withstand freezing temperatures.
You can sow seeds of Siberian iris, Oriental poppy, and Arctic daisy and place the containers outdoors through late winter to propagate your own, inexpensive seedlings for the garden.
There are plenty of hardy annual options too, and the seed packets of those plants will often feature the same key phrases.
What constitutes a “hardy annual?” Those are plants that complete their lifecycle in just one year and which can tolerate a light frost. They germinate, mature, produce, and die within a 12-month period, but they won’t resprout. Instead, they set seed for the following year’s new generation and can sprout in place, without the need to germinate indoors.
Some examples include snapdragon, bee balm, and delphinium; and that’s just the tip of the iceberg. There are so many options to try.
Coneflower, Black-eyed Susan, and verbena are perennial flowers in much of the United States. They’re are also good self-sowers and excellent choices for winter sowing.
Some edible options for winter sowing include the classic cool-season crops – like broccoli, cauliflower and cabbage. Leafy greens – like lettuce, kale and bok choy – are also hardy annual options. Herbs like sage, oregano, dill, and mint are good winter sowing candidates too.
In any case, what’s the harm in trying? If there’s a variety that you want to try winter sowing for your garden, don’t be afraid to experiment and see what happens. If those seeds don’t germinate, the most you’ve lost is a packet of seeds, but you’ve gained a learning experience. The risk is so inconsequential in comparison to the potential reward.
You might have noticed some varieties that I haven’t mentioned as good candidates for winter sowing. Summer edible crops including tomatoes, squash, eggplant, and peppers all need warmer temperatures. For those types of plants, indoor seed starting really is your best bet to get a jump start on the season.
If you’ve never tried starting seeds indoors, trust me – you will love it. It takes a bit more effort and space, but to be honest, it’s one of the most rewarding aspects of gardening for me. Maybe for you too.
How to Winter Sow
In nature, seeds which are cold hardy can weather freezing temperatures, but keep in mind that they get a little natural protection too. Those seeds fall to the ground and are inevitably covered by leaves and other debris to offer a little bit of insulation.
In winter sowing, you need to provide a little protection too, while containing them so that you can transplant them into your garden or landscape beds in spring. So, your goal is to create a sort of mini-greenhouse.
Look around your home, and you’ll find all kinds of options ready and waiting. Look for anything clear or slightly opaque to let in sunlight. It also needs to withstand freezing temperatures and if it has a handle, that’s ideal.
I’m not a fan of plastic, but it’s just a fact of our modern-day life. Fortunately, it’s the perfect material for winter sowing. Plastic milk jugs are the classic choice. When cut in half, they offer plenty of space along the bottom, and the top lets in plenty of light and traps some heat and moisture.
Opaque milk and water jugs, as well as food containers, with clear plastic tops, make excellent mini-greenhouses for winter sowing.
Two-liter soda bottles are another good choice as are lots of food take-out containers with clear plastic lids. Do you ever buy a rotisserie chicken? Save the container, because it works great for winter sowing.
Once you’ve got your container, you need to create opportunities for drainage and for air and moisture venting. There are plenty of ways to poke some holes in the top and bottom of the container for this, but my favorite is to use a Phillips-head screwdriver. I heat up the tip of the screwdriver and touch it to the plastic. It melts a quick and good-sized hole without much effort.
Don’t be stingy when you’re making those holes. You’ll want several along the bottom, so there’s no risk of water pooling at the base of the soil. The top of the container needs plenty of holes as well for venting.
If you’re using a milk jug or a soda bottle, slice around the circumference about 5-6” from the bottom. Don’t cut it completely off. Instead, leave about an inch to work like a sort of hinge for the lid. Voila! You’re ready to winter sow some seeds, my gardening friend.
Be sure to add sufficient holes in all containers to allow for drainage and air circulation. Heating the tip of a phillips-head screwdriver makes easy work of this important step. I heated the tip of a 12-inch galvanized spike to make these holes.
Next, you’ll need soil. Seed starting mix is an option, but since you’re trying to replicate natural conditions outdoors, you don’t need to use a medium that is sterile or as light as is necessary for indoor seed starting. On the other hand, garden soil is a little heavy for this technique, so I don’t recommend that. Regular potting or container soil is perfect.
You’ll need enough soil to allow room for the roots to develop once the seeds have germinated. The seedlings can’t be transplanted into the garden until they have established enough of a root system to rebound after being handled. A soil depth of about 4” is a good rule of thumb for winter sowing.
Once the milk jugs are cut almost entirely around their circumference, the tops are pulled back, and the soil and seed are added. Then it’s simply a matter of putting the tops back into place and securing around the seam with duct tape.
Sprinkle your seeds over the surface and very lightly tamp them down with your hand. Use a light touch to sprinkle a very thin layer of soil over the top of the seeds too. It’s better to use too little than to overdo it here.
Water them in gently, then flip or place the lid over the top. Duct tape works great to secure the top to prevent it from being blown or knocked off, because it’s so durable – even under harsh conditions.
Don’t forget to label the container with the type of seeds you’ve sown. Any type of permanent marker will work, but remember that the container has a few months of harsh conditions in its future. You would be surprised how quickly even permanent markers fade under the circumstances.
That’s why I like to use a paint pen instead. Those are readily available and are least likely to fade in the UV light and cold temperatures. I write the seed variety on the top of the container, but I provide myself a little insurance too. I also write the seed variety on the bottom of the container. The bottom won’t be exposed, so I can know that, come spring, I won’t have to rack my brain to remember what the heck I have thriving and ready to plant.
Curb Your Enthusiasm
The most common winter-sowing problem is the mistake of starting seeds too soon. The winter solstice (December 21st) is a good rule of thumb to go by. That’s one of the busiest times of the year for most of us, so if you don’t have everything ready to go until after the first of the new year, don’t worry.
I don’t usually do my winter sowing until sometime in January, and that might be a perfect time for you too. It’s the perfect way to scratch that gardening “itch” even though the weather outside is still frightful.
Even into February, your area is probably still experiencing cold enough temperatures for several weeks, that your winter sowing container will still be exposed to a sufficient chill period for the seeds which require that time. That said – if you live in a milder climate and pick seeds appropriate to your zone, those varieties won’t require freezing temperatures for successful germination. After all, this technique is all about mimicking what happens naturally in your area.
Once your seeds are sown and the containers are taped up and ready to go, where’s the best place to put them? That depends a little on where you live. If you’re in a colder climate, a sunny spot with access to natural moisture is ideal. Once they germinate, the seedlings will benefit from the warmth of the sun.
On the other hand, those of you living in a milder climate should choose a spot with a little shade. A little warmth is a good thing, but those containers will heat up quickly, so you don’t want to cook them inside that mini-greenhouse you’ve created.
In either case, avoid any area which is exposed to heavy wind. If the containers get knocked around, it will disrupt root growth and can kill your seedlings. That’s why it’s also a good idea to protect them from being disturbed by animals or foot traffic too. So if you can elevate them on a table or a ledge, that’s your best bet.
As the temperatures start to warm, be sure to check on germination periodically. Once the seedlings begin to develop, they’ll need larger openings in the container to provide more air circulation. They’ll also need a little bit of water, so don’t let the soil dry out.
Once seeds sprout and it starts to warm, cut new openings into your containers to allow more sunlight and air circulation to reach the plants.
On warm days, it’s a good idea to open the top of the container altogether to keep the air temperature around the seedlings from getting too warm. This little bit of maintenance and attention will be happening in early spring, so odds are pretty good that you’ll be anxious to get outside and get gardening anyway.
When the seedlings are tall enough to reach the top of the container and have a root system that’s sturdy enough to hold together, congratulations! They’re ready to transplant into the garden.
Once winter-sown seeds begin to reach the top of their containers, it’s time to pull back the covers and acclimate them fully to the environment. These seedlings are ready for transplanting.
All in all, winter sowing is an easy and fun way to get gardening – even in the middle of winter – and grow flowers and cool-season crops for a low-cost investment of your hard-earned budget.
If you’re ready for more on winter sowing, keep an eye out for my Master Seed Starting course coming in January. You can sign up now to be notified and check out more details once the course has launched.
That course will really give you a leg up on starting seeds indoors. For all your summer crops – or if you’re like me and just love the experience of watching the daily development of these little green miracles – indoor seed starting is where it’s at.
I’ve been testing all kinds of indoor lighting options and doing comparison studies to find out what equipment is worthwhile and what’s just a waste of money. I’m also comparing which growing mediums are easiest to maintain and promote the healthiest seedlings. The course also covers sowing seeds directly into the garden too. And if you want a peek and the products I love, use and suggest you consider, I’m starting to list them all in my new Amazon Storefront. Check it out!
If it’s related to growing plants from seeds – no matter which technique you choose – this course will answer your questions and have you mastering the art of growing your own plants for all the seasons ahead of you. I’ll also be inviting students to live Q&A webinars to ask any followup questions or help troubleshoot. So, don’t miss it!
Don’t miss this recording either. You can scroll to the top of the page and click the Play icon in the green bar under the page title. I’m describing additional variety examples and talking you through the process.
Okay – so, which seeds will you be winter sowing this year? Let me know in the Comment below or share your success stories and lessons learned.
Links & Resources
joegardener Online Academy: Master Pests, Diseases and Weeds – Just $47 for lifetime access! Watch for my new course on seed starting coming soon!
https://www.amazon.com/shop/joegardener Our new Amazon Storefront. Here is where you’ll find my favorite must-have gardening gear, seed-starting equipment, books and more.
Corona® Tools – Our podcast episode sponsor and Brand Partner of joegardener.com
Pete and Gerry’s Organic Eggs Pete and Gerry’s – Podcast episode sponsor and Brand Partner of joegardener.com
0 Responses to “130-Winter Sowing: A Simple Way To Successfully Start Seeds Outdoors”
Thanks for this introduction- I listened to it on the way to work this morning. I have been thinking about trying this technique and this episode has pushed me over the edge. We live in similar climates and I hope that my results are similar to yours.
You never cease to amaze me. Just this week I was thinking about growing lettuce in my 2 grow bags on my 2nd floor deck. I planned to cover them with soda bottles ala cloches. I’ve got this device that you stick into the ground or grow bag that has holes in in. You simply attach a water bottle. It goes about 7-8 inches deep. So it waters from around 1-7 inches all the way around.I am also planning on doing microgreens (radishes and broccoli for example) in cells. Of course I have crops under hoops (covered with frost blankets for now and plastic when the real cold settles in. So now with this method I can truly be a year round gardener.This hits my calling of being in love with seed planting perfectly. Harvest is great, but not always what you want it to be. That’s why I’m in love with seed planting. The only failure is not planting them. And when they germinate, the joy of the resurrection.Again, thanks for what you do!Shalom,
John Longard
Well, John. Never ceasing to amaze you sounds like a very worthwhile endeavor. Thanks for the opportunity and you thoughtful comments.
Awesome! It is surprisingly simple and effective. Give it a go. You’ll be glad you did Jamie. Thanks for listening and writing.
I had never, ever considered doing this! I live in zone 5a and we have ridiculously cold weather in January, and a ton of snow in February. The idea of having any kind of seed-starting going on was not even considered, but everything you said about the cold stratification makes so much sense. I’m going to try this with my coneflower seeds and collard greens, and maybe even lettuce once we get into March. Thank you for another fantastic podcast! This is why I tune in faithfully every Thursday morning during my commute. I always, always learn something from you! Thanks Joe!
Love this! I’m so glad you found this enlightening! It’s a ridiculously easy way to sow lots of perennial and hardy annual seeds. You will really be amazed. Be sure to send pics next spring. I’m looking forward to seeing your first experience.
Joe, I fell behind on yard work and podcasts but am trying to catch up. I never did get that winter garden started but did get most of my garden beds smothered in leafs for spring weed suppression and later mulch. If the snow melts today I may get the rest done.This method of cold weather sowing makes perfect sense. I have often had annual and perennial seeds that fell from previous season plants geriminate in late spring or early summer. By late summer they are nice when those greenhouse annuals are looking tired.Some seeds that I have seen sprout after being out on the ground all winter are inpatients, begonnia, snap dragon, ageratium, morning glory, nasturtum, tomatoes, pumpkins, gourds, cone flowers, coriopsis, and colummbine. I can only guess that protecting them from birds and mammals in covers would make them even more successful. I will give it a try.Joe, if you haven’t done it already, try some nasturtum in a corner of your raised beds. They wont take up much room in the bed and they are a beautiful spiller . Susan Evans recommends them to attract beneficials.Regards
Forrest Jones
Nanty Glo, Pa
It always amazes me how many seeds that are deposited in fall come to life the following spring. Something so small and non-descript! The wonders of nature will never cease to keep me in awe!And I have and love growing nasturtiums in my beds. I don’t always do it but when I do, I’m reminded I need to do it all the time. Thanks Forrest.
Joe, great information as always. Your tips on seed starting are beneficial for both beginner and Master Gardeners alike. I always enjoy the variety of seeds from my flowers and herbs that survive the winter months and randomly reseed around my urban nano farm in subsequent years. Of course I leave them alone where ever they pop up. I continue to be complete awe at the potential contained in every seed.
Me too, Gary!!! Perhaps that’s why I love starting seeds so much every year. I stay in perpetual awe of all of this!
Yes, it is truly an amazing work of nature that seeds are programmed to germinate at just the right time. And some require a chilling period of many hours so that they are not lost to a brief chill followed by a warm up and then a deep freeze again. I have never been south in the early spring. Makes me wonder Joe, are spring flowers, the bulbs we plant in fall, annuals in the South or do you get enough winter chill to keep them comming back year after year at the right time in spring.
Thanks Joe!
It depends on the bulb. Tulips for example are really only good for their debut year here in the SE (Atlanta). However, daffodils are prolific and re-emerge every spring bigger and better than the year before. In fact, about every 5 years, you need to go in and divide them as they can reproduce so much they end up crowding themselves out and then they start to go downhill from their original potential.
Hey Joe, great info as always. I’m up in North/central Alberta, Canada gardening in zone 3a (its an adventure). It makes things interesting for sure with frequent frosts in mid May (June last year) and September so any chance I get for an early start I’ll take it. I am excited to try some winter sowing this year, but was wondering why not just direct seed and cover rather than have to transplant? I certainly understand when doing many seeds in one like your photos, but I can already envision one of my raised beds with 15-20 “decorative” milk jugs each housing its own baby cabbage.
Thanks Stephen. Nothing at all wrong with direct sowing. The main advantage of sowing into containers is so that you can divide and plant where you want them in spring. If you already know where you want them and are sure you can ID them over neighboring weeds sprouting at the same time, then by all means, go for it.I do like knowing that what I’m sowing is going where I want it, and I don’t have to worry that I may be cutting desired seedings when I do my early spring weeding with my scuffle hoe.
Good Day;Love the show. I can not help but admire your grow room. I am trying to build the ultimate room. I have one question. What is the wattage of your grow lights?Thank youJohn
Good Afternoon…I was so happy to hear you talk about this method. I have succesfully done winter sowing for two years. It has allowed me to mass produce plants such as many different varities of milkweed, salvias, parlsey and agastche, to name only a few. It was so easy and very sucessful here in Shelbyville, KY. People thougth I was crazy when I would tell them about my sucesses with this method. Glad to get the tips on labeling becuase that was indeed my biggest issue. The only other problem?? was having so many wonderful plants to get in the ground or give away. I love the podcast! I have been gardening for over 40 years but learn something new each week. Thanks so very much!! Becky Kirts
Hi Becky! Thanks so much for sharing your success story with me here. You have certainly done well with your winter sowing, that’s for sure!
Glad to know the labeling tip helped! And thanks for the kind words about the podcast. I always love hearing that. Thanks for listening and writing.
Hi John and thanks. I now have quite a few different lighting configurations as I’m always trying new options. But i would say it’s safe to say the majority of my lights are 300W LED full spectrum lights. Hope that helps.
Hi Joe!
I really enjoy listening to your podcasts while driving to the Shenandoah Valley and Blue Ridge Mountains, my favorite escape from OH! I do enjoy the ones that are more scientific, not too nerdy and very easy to comprehend. I am going to try winter sowing again, just experimented last year for the first time. It was very fun. Will also use this concept with the third graders at school, I’m their lunch lady, to make them even more curious about gardening and eating vegetables!
I do have one question, have you ever thought about a podcast addressing microgreens? I have found a few good books lately and I think it may be an interesting topic for those in apartments or in cold climates like OH and further north. I’m going to plant some microgreens and see if I like them. I’m a very picky eater and greens aren’t my favorite! I have used herbs at this stage, cooking for one doesn’t require many fresh herbs. I’ll never use a full grown plant before it’s bad. It was just a thought!
Thank you again for all of your hard work. Great information!
Shelley
Hi Shelley. Thank you for allowing me to keep you company on your beautiful drive. I love that part of the country!
I have not considered a podcast on growing microgreens…until now. Thank you for the suggestion. it makes sense to address for the very reasons you mention. I am adding it to my list of future topics right now. I really am! Thanks Shelley for taking the time to right with your suggestion.
That would be great Joe! The two books that I’m looking at now have some great information, maybe a starting point for your research and my reason for suggesting topic. Indoor Kitchen Gardening by Elizabeth Millard, title pretty much explains content and How to Grow Nature’s Own Superfood, Microgreens, Second Edition by Fionna Hill. She focuses on outside production as well. Thanks again for exploring this subject! Shelley
Got it. Thanks for the book titles!
Hey Joe, at minute 15:50 you mention Russian Olive… FYI that is considered an invasive species invasivespeciesinfo.gov/pro… Let’s help our native animals and pollinators by providing plants that are safe for our environments to grow. 🙂
Hi Andrea and thanks for chiming in on this. I did catch that after the fact and have it slated for an edit update. Thanks for listening!
How late can you start winter sowing? How long does it take for seeds to germinate to a point when they can be planted. I am located in New Jersey
Hi Joe,
This couldn’t be more informative. I especially love the list of plants, though I’m going to take your advice, throw caution to the wind and see what happens. What have I got to lose?
Still, I would like your thoughts on using seed trays and keeping them in my very modest, unheated greenhouse as opposed to the jugs. Of course I would have to water periodically because they won’t be getting snow or rain inside, but I wondering if you think It would be equally successful?