Winter Sowing Tips: Seed Starting by Zone + Additional Info
Not sure when to winter sow in your growing zone? This guide breaks down what seeds to start and when, based on zone-specific timing.
After I shared my Guide to Winter Sowing, a lot of you had questions. How do I know what to sow and when to sow? What kind of containers can I use? What about watering? Here’s how I decide what to sow, when to sow it, and what really matters.
Winter sowing means planting seeds outside in winter and letting nature handle the timing. The seeds are placed in outdoor containers with lids or covers, mimicking a mini greenhouse effect. You’re letting cold, moisture, and daylight shifts tell seeds when it’s time.
It’s about as hands-off as seed starting gets.
How do I know if my seeds are good candidates for winter sowing?
Flip the seed packet over and look for phrases like these:
- Hardy seeds
- Seedlings can withstand frost
- Sow outdoors in late autumn or early winter
- Sow outdoors in early spring when nights are still cool
- Needs pre-chilling
- Requires stratification (cold, moist conditions)
Those phrases are your green light for winter sowing. Of course, your climate and gardening zone will play an important part in the success of winter sowing.
How deep do I sow my seeds?
The general rule of thumb is to plant twice the depth of the seed’s smallest dimension at the spacing indicated by your seed packet. Depth matters, but it’s not the only thing that affects germination. I go deeper into what makes seeds sprout (and what can stop them) if you want to understand the “why” behind it. Honestly, I don’t worry too much about proper spacing or depth with tiny seeds. I sprinkle them in and cover them with a light layer of soil. Once they start coming up in spring, I thin as needed.
What do I use if I don’t have enough milk cartons?
There are a lot of great upcycle container ideas out there. Basically, if light can get in, it’ll work. Some options I’ve used or seen work:
- Soda bottles
- Bakery containers
- Clear storage totes
- Deli chicken containers
- Travel tin foil containers
- Meat and cheese platters (for shallow-rooted seedlings)
- Juice cartons with the tops cut off and a baggie over the top (more suitable for southern locations)
Just be sure if you are using a container that doesn’t have a lid or cap, you drill in a few ventilation/moisture holes along the top.
What if I don’t have snow?
Winter is just a cooler season, not necessarily bitter cold and snow. Winter sowing is really just about getting a jump on spring, allowing nature to take care of everything. It’s like greenhouse gardening on a small scale.
When is the earliest I can start Winter Sowing?
The Winter Solstice seems to be a good starting point. The days are at their shortest, and typically, the temperatures are at their coldest. The concern with starting too early is that the seeds will begin to sprout while the temperatures are too low to support the plant. By planting in the “dead of winter,” you can be fairly confident that the seeds won’t start until spring is beginning.
What do I do come spring?
From here on out, they’re just normal seedlings. You’ll want to remove the lid during the daytime to harden them off and transplant them when the soil is warm enough.
What about watering?
Rain and snow usually take care of watering for you. By keeping the cover off your container or cutting ventilation holes, rain and snow will enter the top, and excess water will drain through the drainage holes. If you notice your soil is looking dry and crumbly, just dribble water along the edges of the soil. It won’t take much water, and you want to do it slowly so you don’t dislodge the seeds. Be sure to use cold water so you don’t shock your seeds.
Once spring arrives, keep an eye on your sprouting seeds. Most of the time, things balance themselves out. If you notice your containers seem soggy, try moving them to a sunnier location. If they seem to be drying out frequently, move them to an area that gets sunlight but not direct sunlight. If they need to be watered manually, use water at the same temperature as the outdoor temperature and gently water around the edges.
What to Winter Sow Each Month According to Your Gardening Zone
These are guides, not hard rules. Trial and error is the best way to determine when to grow what is in your zone but knowing your zones and frost dates is still useful. Click these links below to find out what zone you’re gardening in.
US Garden Zones | CAN Garden Zones | EUR Garden Zones | Other Zones
Also be sure to check out which seeds you should be planting in your growing zone.
Zone 3 Growing Guide
Zone 3 typically experiences extremely cold winters, with temperatures dropping as low as -40°F. With a considerably short frost-free period and harsh winter conditions, Zone 3 gardeners utilize winter sowing to gain an edge in the race against time.
February
February is the best time to start perennial flowers and hardy annuals in Zone 3.
- Bellflower
- Blanket Flower
- Butterfly Weed
- Canterbury Bells
- Coneflower
- Delphinium
- False Indigo
- Helleborus
- Hollyhock
- Hosta
- Lily-of-the-Valley
- Mountain Bluet
- Ox-Eye Daisy
- Pincushion Flower
- Pyrethrum
- Rudbeckia
- Veronica
- Yarrow
March
March is the best time to start most herbs and any plants that require stratification if you’re in Zone 3.
- Basil
- Broccoli
- Brussels Sprouts
- Hops
- Horseradish
- Kale
- Marshmallow
- Monkshood
- Onions
- Peas
- Spinach
- St. John’s Wort
- Swiss Chard
- Tarragon
- Wormwood
April
April is the best time to start frost-tolerant vegetables in Zone 3.
- .Beans
- Beets
- Bok Choy
- Lettuce
May
May is the best time to start tender plants in Zone 3.
- Corn
- Cucumbers
- Eggplant
- Peppers
- Pumpkins
- Sweet Potato Slips
- Tomatoes
Zone 4 Growing Guide
Zone 4 experiences cold winters with temperatures ranging between -30°F to -20°F. With a moderately short growing season and the ever-present risk of late spring frosts, Zone 4 gardeners turn to winter sowing to optimize their planting timelines.
January
January is the best time to start perennial flowers and hardy annuals in Zone 4.
- Asters
- Astilbe
- Balloon Flower
- Bee Balm
- Blazing Star
- Carnation
- Coreopsis
- Daylily
- English Daisy
- Helenium
- Iris
- Lamb’s Ear
- Lupine
- Phlox
- Poppies
- Violas
February
February is the best time to start most herbs and any plants that require stratification in Zone 4.
- Basil
- Bergamot
- Broccoli
- Brussels Sprouts
- Chives
- Chamomile
- Clary
- Comfrey
- Garlic
- Kale
- Mint
- Onions
- Peas
- Peppermint
- Spearmint
- Spinach
- Sweet Woodruff
- Swiss Chard
- Thyme
- Walking Onions
March
March is the best time to start frost-tolerant vegetables in Zone 4.
- Bok Choy
- Beets
- Beans
- Lettuce
April
April is the best time to start tender plants in Zone 4.
- Corn
- Cucumbers
- Eggplant
- Peppers
- Pumpkins
- Sweet Potato Slips
- Tomatoes
Zone 5 Growing Guide
In Zone 5, gardeners experience cold winters, typically falling between -10°F to -20°F. With Zone 5 characterized by a distinct winter chill and the potential for late spring frosts, winter sowing provides a reliable means to kickstart the growing season.
December/January
Late December and early January are the best times to start perennial flowers and hardy annuals in Zone 5.
- Blackberry Lily
- Catmint
- Chinese Lanterns
- Chrysanthemum
- Clematis
- Cupid’s Dart
- Evening Primrose
- Flax
- Heather
- Jack-in-the-Pulpit
- Primrose
- Shasta Daisy
January/February
Later January and early February are the best times to start herbs and plants requiring stratification in Zone 5.
- Agrimony
- Basil
- Broccoli
- Brussels Sprouts
- Garlic
- Kale
- Lavender
- Onions
- Oregano
- Peas
- Sage
- Spinach
- Swiss Chard
- Valerian
February/March
Late February and early March are the best times to start frost-tolerant vegetables in Zone 5.
- Beans
- Beets
- Bok Choy
- Lettuce
March/April
Late March and early April are the best times to start tender plants in Zone 5.
- Corn
- Cucumbers
- Eggplant
- Melons
- Peppers
- Pumpkins
- Sweet Potato Slips
- Tomatoes
Zone 6 Growing Guide
In Zone 6, gardeners typically experience moderate winters, with temperatures ranging from 0°F to -10°F. Where winters can be moderately cold, and springs are often unpredictable, winter sowing emerges as a strategic ally for gardeners in Zone 6 seeking a head start on the growing season.
December
December is the best time to start perennial flowers and hardy annuals in Zone 6.
- Broom Flower
- Fleabane
- Fountain Grass
- Lily-of-the-Nile
- Red Hot Poker
- Sea Pink
- Verbena
January
January is the best time to start most herbs and any plants that require stratification in Zone 6.
- Agrimony
- Basil
- Broccoli
- Brussels Sprouts
- Garlic
- Hyssop
- Kale
- Madder
- Onions
- Sage
- Spinach
- Swiss Chard
February
February is the best time to start frost-tolerant vegetables in Zone 6.
- Beans
- Beets
- Bok Choy
- Lettuce
March
March is the best time to start tender plants in Zone 6.
- Corn
- Cucumbers
- Eggplant
- Melons
- Peppers
- Pumpkins
- Sweet Potato Slips
- Tomatoes
Zone 7 Growing Guide
Typically experiencing mild winters and warm summers, Zone 7 can still winter sow. Where these mild winters and occasional frosts characterize the climate, gardeners can cultivate a diverse range of frost-tolerant vegetables.
December
December is the best time to start perennial flowers, hardy annuals, and plants that require stratification in Zone 7.
- Blue Beard
- Broccoli
- Brussels Sprouts
- Garlic
- Kale
- Leadwort
- Onions
- Pampas Grass
- Persian Buttercup
- Peruvian Lily
- Spinach
- Swiss Chard
January
January is the best time to start most herbs and frost-tolerant vegetables in Zone 7.
- Arnica
- Basil
- Beets
- Bok Choy
- Collard Greens
- Lettuce
- Turnips
February
February is the best time to start tender plants in Zone 7.
- Corn
- Cucumbers
- Eggplant
- Melons
- Peppers
- Pumpkins
- Sweet Potato Slips
- Tomatoes
I walk through ways to garden in cold climates with short seasons if spring always feels late and fall comes too fast.
Still Wondering About Winter Sowing?
If you’re about to try this, you’re probably wondering…
Pin this for an easy, zone-by-zone winter sowing reference you can come back to every year.
This works whether winter is brutal or just kind of annoying. You don’t have to overthink it or get everything perfect. Set the seeds up, let winter do what it does, and see what shows up in spring. That’s half the fun of winter sowing anyway.
What’s your favorite thing to start this way? Be sure to share in the comments below!
Is there a schedule like this for flower seeds per zone?
I pinned it, btw 🙂
Any guidance for what to start sowing and what and when for zone 8 b?
Thank you so much for this list of seeds to sow and when. It is hard to decipher which ones at what time from any site that I have seen about Winter sowing. I am in zone 3 northern Wisconsin and have great luck with Winter sowing and I am just starting now on March 1st. I feel like I’m a bit late but we have long cold Winters and I am excited to see how it will work out this year. After a long winter it is difficult to keep from purchasing tons of plants-winter sowing is the economical ticket!
Do you have anything listed for zone 8?
Hi Jessica: Thank you for posting this guide. I live at USDA Zone 6b/7a, Philadelphia suburbs. Any idea whether I can winter-sow some daikon radish seeds? When is a good time. Thanks.
Not Jessica but I’ve grown daikon in 7a and planted in August to grow through winter so you could probably start them in December or even now. I’ve never transplanted radishes of any kind though so I don’t know how they do with that.
Thank you for breaking it up by zone. Trying this for the first time and started some perennials. Was wondering when/if to start tender things. Zone 4 so will be ready to do in April.
The guide stopped at zone 7. Please let me know what it is for zone 8a. Thanks
Me, too! Zone 8, but long drawn out wet cold winter along pacific coast …no way we can set out squash, tomatoes, etc until mid may; other veggies late april early may, peppers late may/early June. So I too am interested in this for zone 8 because starts are just getting too expensive!!
This guide is specifically for the winter sowing technique of sowing in jugs which create a mini-greenhouse. It doesn’t refer to putting out plants or starting seeds in the winter without protection.
nice information
It is early March now and I am in a zone 6.
I totally forgot about winter sowing– I had read about it last year–
Can I still plant some hardy perennials using this technique or is it too late for this?
Thank you!
Rose
Hi. I think you may still be able to plant. There is a winter sowing group on FB by Sheryl Mann.
Hello Jessica!
This planting system looks so exciting. My husband just lives for fresh grown tomatoes. I am going to try this. Being in western KY, zone 7, I figure to plant my tomatoes and some green peppers in February.
How many tomato seeds to sow in a gallon milk jug without being overcrowded? Or would a taller container be better?
We have been buying plants from Wal Mart and they don’t seem to last too long, we get one batch of tomatoes then the plant starts to die from the bottom up. We figure they are sick with something when we bought them. So the next garden will be in a new location with home grown plants, I am saving jugs! I am excited to start my flowers too!
Hi, I’m in Wisconsin and am trying this for the first time. When should seedlings start to germinate? I put tomatoes out late February but nothing has sprouted yet. Please let me know what you think. Thank you and Happy Easter!
Fairly new at gardening. What is the best way to water them? I would think just pouring in water would not be good.
I like to dribble it along the edges of the container.
Newbie gardener here. Since the Guide only goes up to Zone 7, am I to take that to mean that attempting Winter Sowing in Zone 8A would not work? Thanks.
Hi Carol! You might be able to winter sow, but your climate may make it so you don’t really need to. I’m not familiar with gardening in such a warm climate. I’d ask locals in your area for advice.
I live in central FL, zone 9a/b. While it isn’t totally necessary to winter sow here, it is beneficial. It helps to protect from pests and helps prolong length of time between watering. Sure, we don’t get freezing temps too often, but having the jugs does make it easier to protect when we do gave them. The key is to not start too early. No earlier than late Dec, but mid to late Jan worked best for me. It’s very difficult to wait, what with temps in 60-80. But if you start too early, the seedlings will need to be transplanted, long before the last chance of frost. You can also sow your seeds in jugs during the warmer months, for a jump start on the next cycle of planting. I just suggest you keep the jugs in the shade, and regularly check for need to water.
Thanks for the info for us southern gardeners?
thank you! from North Texas!
Dear Jessica, Quick question – after winter sowing, in the spring, do you transplant from milk containers into the ground?? Can I do that so that the crop has more room to grow, more nutrients, etc. How has this gone for you if you’ve done this before? Thanks! Kate
Yes, once the soil and air temperatures are appropriate, you’ll want to harden them off and transplant them into the garden.
They don’t require hardening off if winter sown ? No?
i have just purchased almost 4 acres in northeatern ga. moving from TEXAS to get out of the insane world cities provide. my only gardening to this point is tomatos from seed. thanks for your site. look forward to using your milk jug starter kit…lol, why didnt i think of that?
thanks
Can cabbage be planted the same time as Broccoli? I don’t see cabbage mentioned.
Yes, Shaela, you can. It’s not an all-inclusive list because I haven’t gardened in every zone.
I have no green thumb whatsoever. I kill everything but would like to g8ve.it.to this a shot. I cannot find my zone. We live in NW Pennsylvania. My father seems to think that they will freeze and die if you put them outside because of the snow/frost. He’s skeptical but I’d still like to try. Though he does have me wonder how they do not freeze??
Can u help me find my zone?
There is a lot of variation of zones in NW Pennsylvania, but if you go here, you can pop in your zip code and it will tell you which one you are in.
As far as the freezing, the seeds won’t be hurt by freeze cycles, only the seedlings will. The seedlings won’t begin to sprout until nature gives them the cue that it’s time. The mini-greenhouse created by the milk jug protects them from the temperature fluctuations we often see in spring.
I dont even know what zone am i? I am in Glendale Arizona border of Phoenix and Glendale.I started winter sowing 1/15/16 in milk carton, i try to watch them closely, im not sure how often to water them, its been warm here lately 70’s this week
For your area (I’m assuming you don’t have a freeze if it’s in the 70’s in January), I would water just enough to keep them moist. If they are drying out quickly, you can move them to an area where they are getting dappled sun instead of full sun.
I used to live in the desert climate for more than 30+ years. This young lady is in the 7 to 8B or even possibly a 9 growing zone. Weather is unpredictable this time of year and she could be looking at 70 to 75 degree days and still have 35 to 55 degree nights. What is chilly to us and chilly to the desert regions is completely different. She should check sites like Mother Earth or Farmers Almanac to find her exact zone…. this advice is from someone who survived zone 11, but loves her zone 5.
This is awesome! Looking forward to trying this method. Thank you!
Great information,I’m going to give winter sowing a try.
It would be nice if you had all the growing zones, where are 8-11? I’m new to growing in Zone 8B and still learning when to start seeds or direct sow.
Winter sowing is best suited for areas that have sustaining frosts. I’m not too familiar with gardening in warmer climates, but I think you can follow the standard seed packet directions. I encourage you to check out SchneiderPeeps. She is a great source for southern gardening.
thanks… i’ll let you know how it goes.
I am in zone 7… central mountains of Arizona… we have had an unusual warm spell and many of my jugs have started sprouting …. now they are predicting a cold storm this weekend…. should I cover the jugs or just pray?
If you have sprouts and/or greenery beginning to show, I would cover them when there is risk of frost. Under the soil they are protected, but once they emerge, they are exposed to the elements.
Is there a guide to find your zone?
Hi Sharon!
I just updated the post to include the US, Canadian, and European growing zone charts. I also included an additional link for those who don’t have a zone map so they can figure out what zone they would be based on annual temperatures. I hope that helps.
Thank you
You are so welcome Sharon.