Winter Sowing- General Questions

Dallas, TX(Zone 8a)

Hi all- I know what winter sowing is... I'll start out by saying that. I am just looking for some guidance as far as doing it in southern climates (I'm in zone 8). I am a little confused on the stratification thing. I mean I read they need a period of 90 days WARM weather first so stratification may be a problem... but I would think it would be a problem up north. Then I read that you are supposed to keep them cool for 90 days so in the south you may need to refridgerate them first, which makes more sense. Sooo, can someone tell me, in a nutshell (or a novel if you prefer!), what that means exactly? Secondly, what seeds work best for this in warmer climates? Any I should NOT try this with? And finally, when should I put the seeds out? Again, I understand how to do it as far as containers, covering them up, etc. and the concept behind it, I just don't know the specifics as mentioned. I didn't see a forum for this particular topic so I hope I put this in the right place. :) Thanks!!! Jamie

San Augustine, TX(Zone 8b)

Hmmmm Jamie...I'm waiting with you for answers! ;))

Dallas, TX(Zone 8a)

I really have looked online but all I can find is stuff that says "in southern climates you may have to...." but it's very vague. Surely someone on this website, from the south, winter sows. We KNOW you're out there guys.... COME ON AND HELP US!!! :)

I am from Z5 but I have enjoyed many successes with winter sowing. One of the rules of thumb is to let the deciduous trees in your area be your guide. When the last of the leaves has fallen, it is now time to prepare to winter sow. Around here, the last of the leaves are gone by the second week of November but that may not happen for you until the last week of December. Regardless of when the last leaf falls, I'm waiting until after the first of the year to start as it was too darn hectic starting before the holidays last year to prepare 200 trays. There is truly no time frame as to when you have to start and I continue winter sowing until at least February.

Seeds that are perennial and native to your area generally work best in my opinion. There are many sites that can help you determine which seeds to select. Any native plant organization in your area will most probably maintain lists of seeds that exist naturally within that range. I belong to Wild Ones and normally revert to their lists. I also rely upon the Illinois Native Plant Society's list. Each state will have some sort of list out there to help. If you do not have lists, look close at the seed packs as the descriptions will help you too. Just remember that many plants reseed and germinate outside in all zones so please don't get overwhelmed.

Don't get hung up on cold stratification. This is merely a chemical process that breaks the seed's dormancy. Were talking layers of soil, seed, then leaf. Add repeated frreze and thaw cycles and you've got stratification. Many seeds do not require stratification. The individual seed you choose to winter sow will dictate whether it requires stratification or not. Cold stratification to me is tricking Ma Nature. I take vermiculite and wet it so that it is damp, never moist. If it is too damp, I add more vermiculite. I then get a little Rubbermaid food storage container and label it with the date and the name of the seed. I mix the seed into the vermiculite and pop the mixture into the refrigerator for 30, or 60, or 90 days- depends on the seed. You can use paper towels and ziplocks. It really doesn't matter. Some seeds are what is referred to as double dormancy. This means you refrigerate them, take them out for a set period of time, cold stratify them again, and then take them out. White Fringe Tree as well as Solomon's Seal are two that require a double if not a triple cold stratification to break embryo dormancy.

There are some common practices to winter sowing but preparation will vary from seed to seed. Some seeds need light to germinate some seeds won't germinate in light. Some seeds need to be soaked for a few days with daily changes of water, some don't. Some seeds need to be scarified, some don't. These are things you will learn as you go when you ask questions.

The major benefits to winter sowing are that you toss out the need to refrigerate for all practical purposes. You will not need to "harden off" your seedlings as they are already used to the elements because they were germinated in them. You won't need an expensive light set up as your trays will go right outside into the elements. You do not need to allocate space inside your home as these trays could actually be tossed in snow bank. Your plants are hardier because they were germinated outside just like many professional growers do it... think about it- those hoop houses are really nothing more than big winter sowing containers. Your seeds that germinate will thrive out the gate because they will be hardy to what ever zone you winter sowed them in. You can use virtually any container to winter sow in to include milk jugs cut in half or shoe boxes lined with foil or rubbermaid shoe storage boxes. Lots of people use foil pie tins. Just drill a few holes in the bottom for drainage and cover it with shrink wrap that has a few vents in it and off you go. All you do is wait. Thanks to genetics, each seed will know when it is safe to begin germinating. You could have 20 trays and each tray will begin germinating at a different time. The seeds are programmed to know when to start shooting up the green. Last but not least, starting seeds inside is sort of unnatural. We are forcing them to germinate when we want them to germinate and not necessarily when they are ready to germinate. There are many airborn pathogens in a home that can destroy seeds sown indoor. Winter sowing reduces this substantially. Seeds that are winter sown are not nearly as likely to be plagued with fungi.

Couple of tricks-
To reduce soilborn pathogens, I take whatever medium I am going to plant the seeds in and pour boiling water on it then cover it. Spread it out somewhere to dry out before using it. Microwaving your planting medium works well too and I have even tossed it in the oven for a few hours at 200F. Big help if you are going to use compost as you won't get any surprise weeds. Lately I have been too lazy to do that so I went out and purchased Schultz moisture plus.

Fill your containers with your medium of choice. Place your seeds on top of this. Now cover with milled sphagnum moss or rinsed sand. This helps reduce the possibility of fungal infections too. I don't normally bother and just top mine off with the same planting medium unless it is a "touchy" seed such as that white fringe tree.

Donít let your trays dry out. Don't over water and keep your saran wrap in place until you see green. Then remove it so air can circulate better.

Winter sowing leaves one with extremely healthy seedlings as allowing Ma Nature to do what she does best virtually eliminates postemergence and pre-emergent damping-off diseases which affect all species of seeds and seedlings.

Let them mature and transfer them to their permanent location. Zone is pretty much irrelelvant in my opinion unless we're talking the tropics.

This site contains information on when to start what type of seed-

Here is an article written by the woman I contacted to help get me going-
She was very responsive and did a great job of holding my hand as I freaked out over placing hundreds of dollars of seed outside.

Does this help you Jamie? ;)

Tee he, don't ask me how to winter sow carnivorous plants. I need help myself. Time for me to go ask for help as I have a decent sized order of CP seed coming in.

Dallas, TX(Zone 8a)

Yes, that helps!!!! Thank you so much for taking the time to respond. That is my fear too- taking all the seeds I have collected, aquired, purchased, etc. and putting them outside, in the winter. Just seems "wrong" but like you said, it's more natural that what most of us do. Which is start seeds inside. Thanks again! I will research the seeds I plan on winter sowing- which I will do in January it looks like. :)

Oh Jamie, not only have you caught ponditis...
you have now succumbed to seeditis.

Kannapolis, NC(Zone 7b)

Equilibrium you are a wealth of information! This is not the first time I have learned from your threads. Thanks for posting so as to help me avoid some of the 'learning the hard way' learning..


San Augustine, TX(Zone 8b)

WOW! Great answer! Seems I'll be trying something new this winter.

Dallas, TX(Zone 8a)

Equilibrium- I can't do anything just a little bit. If I am going to garden I have to have all flowers, regardless of how they do in my zone, every type of garden, every obsession, every "collection," etc. My seeditis started first though. However, I think I may send DH over the edge if he sees containers of dirt in the fridge. I just got him over the whole tulip and daffodil bulbs in the fridge thing! So he bought me a mini-fridge for the garage. Wasn't that sweet?! :)

Kannapolis, NC(Zone 7b)

Gotta love those DH's!! I lucked out that we have our old one from when we moved. When that thing goes out.... ;0(

This is one of several threads I will be printing and re reading...

Ha fooled you ncgardenaddict... I take good notes. It doesn't hurt that I have actually done this before and have made more than my fair of mistakes though.

And Dear Sweet Jamie, it is so nice to know that I am not alone suffering from gardening oc disorder. Pssst... my husband got so sick and tired of finding everything but food in our frig that he bought me an entire refrigerator to stock as I so desire.

Dallas, TX(Zone 8a)

I'm sure I'll graduate to having a subzero fridge in the garage before too long. HA!

Thata girl!

Taylor, TX(Zone 8b)

I've been here a few years and finally figured out last year that winter sowing is the ticket. It gets warm so fast here the weeds take over. Last year I threw down some leftover seeds...snapdragon, arugula, some other things. When spring came there were new "weeds" everywhere. The I realized what they were. If you sow in the spring or summer it gets hot too quick. Also I looked at some local info for dates to sow. I poked some nasturtium in the grownd last December and they all came up, too. The only things I waited on was pumpkins, watermelons, sunflowers. maybe I should've tossed them out, too. The one thing I remember happening last year was I tried "fall sowing" about this time, then it got hot again. I hate watering, so that didn't help. The ones I gave up on and tossed that actually grew... was about the end of October/early November. This year I have a plan...till it up, then spray with roundup. Then...thanks to the rain stuff is popping up (dormant weed seeds). Spray again. Then...wait til about Hallowenn and toss my seeds. This year I'll use sand since I had random clumps of stuff last year. I think it'll work out great.

Kannapolis, NC(Zone 7b)

Witch - that makes perfect sense to me!!

Dallas, TX(Zone 8a)

I thought you had to wait awhile to plant anything after you spray Roundup? Also, I have issues as far as how to identify a weed from a seedling! Unless it is an obvious weed, I'm cluess! I overseed w/ fescue in the fall and always hit the edges of my beds. Well, right now I have little sprigs of what I think is fescue popping up in one of my beds, but I am also a big offender of just randomly tossing seeds now and then so I can't be 100% certain. Because of the pattern of sprouts, I am pretty sure it's grass though...
So are you saying you don't do the whole routine of putting them in covered containers and all that? You just toss them directly on the dirt in your garden and leave them? Is there anything that DIDN'T come up that you tossed out? I was thinking about doing my morning glories, touch-me-nots, forget-me-nots, and maybe datura that way. Any thoughts on those seeds in particular?

Yes, what Witch does is called broadcast. I love it and it can work really well! I am sometimes hesitant to do that though around here in my area as we are inundated with English House Sparrows and European Starlings. The European Starlings seem to flock and decimate whatever I have tossed to the wind and then other critters come in to scavenge what remains. Was very depressing to me the first few times I tried to broadcast nodding wild onion and a few others. I had to stand there and watch them pick the ground clean just like they do when we reseed the lawn in fall.

Hi Witch, are you sure you want to use RoundUp twice? If it rains really good, are any of those weeds coming up the type that would pull up easily? If they are coming up that fast, they may have very shallow roots and might just slide out of the ground easily after a nice rain. RU is a short life chemical but there are some issues with repeated use and corresponding runoff.

Kannapolis, NC(Zone 7b)

Hey Equilibrium - I heard something else about Roundup - this is second hand info from an MG I met that has a landscaping business. She said that round up does not break down in cool temps (under 70 degrees I believe) and goes directly into the groundwater.

Do you know anything about that?

I usually use it as a last resort myself but I do use it.

Bingo! Not exactly 70F though. The threshhold is slightly lower than that but at this time of year, the odds of it breaking down are not that great. It is a product that was designed to be used under certain conditions.

There are other issues with the use of it at this time of year that are sort of complex. Best to hand pull even if you have to get out there in a rain poncho.

Dallas, TX(Zone 8a)

I don't really have out of control weeds. It's mainly grass- but my bed w/ the fescue doesn't have that issue (with the Burmuda grass that is) b/c there is a sidewalk between it and the lawn. But we had to clear out a bunch of overgrown [deleted] when we first moved in and remenants still come up. Namely pecan and oak saplings that were allowed to grow beyond simple sapling status so it was pretty much like removing small trees. The bane of my existence is wild morning glory. I don't know if that's the real name, but that's what everyone around here calls it. It comes up like ivy- will grow as groundcover, up a fence, into trees, whatever. Red berries form on it if you leave it alone. But the vine part grows off these really thick root like things that grow horizontally in the ground. If you pull them out, they rip along the soil line and pull up any plant in their path. So, I do spray those with horticultural grade vinegar. Even that doesn't work 100%, but I don't know what else to do! The only seeds I broadcast is the fescue and I use Pennington. Supposedly that coating on the seeds keeps birds away. Seems to work in my yard...


Kannapolis, NC(Zone 7b)

Ohhh Jamie - hope I don't make any enemies with this but b/c of the wild version I hate morning glories!! I am with you there.. They are EVERYWHERE in my yard, garden, grass, pots, I'm surprised they aren't in my house! I will tell you a story - last year I had one that snuck up one of my outdoor torches. I cut it at the base and left the vine part on the torch. That sucker keep blooming for 2 WEEKS with no roots! I couldn't believe it myself so I kept checking it... Scary stuff!


Dallas, TX(Zone 8a)

Nicole- I can relate!!! I have to spray it with LOTS of vinegar and it only works if the vine is in full sun and it's really hot outside. I normally dig down to where the main root is and cut it off (rather than pull it 25 feet horizontally across my beds) as deep as I can. If it's cutt off pretty far below the soil level then it seems to stay away. As for the vines themselves, well, they like to twine up my wrought iron fence. I have cut them off before at ground level but didn't untwine the vines until they died back, since it's easier then. Well 3 weeks later they were still green and holding tight, complete with the red berries all over them. I do like regular MG though. Except I planted some in shade before I knew better and of course it didn't bloom. Try as I might, I dig up that vine everytime I see a sprout but 2 and a half years later it still comes up. Of course the area that I moved it to (the big mass of roots I tried to transplant) wouldn't come back. For me that dispelled the theory that MGs must reseed to get a plant again the next year. Mine never did bloom to even produce seeds and that darn vine just keeps on coming back!

Kannapolis, NC(Zone 7b)

Hee - and to think of all the things that won't live no matter what! NOT fair!

Dallas, TX(Zone 8a)

Not to get way off topic, but my mom is a prime example of this. We had beautiful red tulips in our flowerbed at our house in New Mexico when I was a little kid. Every spring, like clock work, they came up like little green soldiers with red hats, in a nice row. They bloomed for a long time too- in dry NM heat mind you. So when I bought my house and started gardening I asked her how she got those tulips to grow like that In hot climates the bulbs themselves normally have had it after 2 or 3 seasons, much less come back year after year and look wonderful. Her response? "You mean I was supposed to 'do something' with them?" No, she never fertilized, dug up and replanted, nothing. No mulch, no water, just left them! I guess God likes to keep us in check- reminds us that we aren't running the show as much as we think we are! Jamie

Hi Jamie, get a sponge bottle tipped stamp licker bottle from Office Depot or from Office Max. Locate some BrushBGon. Not the concentrated form just regular strength. Pull the vine down and lay it on an el cheapo tarp and dab the undersides of the leaves with the product. Leave it be for 10 days as you want the chemical to go down into the roots. At about 14 days, go ahead and dig up your nasty. Some vines require a second treatment. I have had to go at Porcelain Berry Vine 2x. One thing, don't bother applying the chemical unless your temps are going to be over 60F but no higher than about 85F. Plants go dormant at lower temps and will not intake the chemical. At higher temps, most plants shut down to conserve energy and will therefore not suck down the "happy juice". You really want to try to go for them around noon when they are photosynthesizing their little hearts out. You can always wait until spring to get it if outside temps aren't in that range.

If you want to cut the vine at the base, you can do this too. You would just need to paint the area exposed with BrushBGon. Just in case you don't kill the vine the first time around, only cut it down to about a foot. That way you can go back and "hack at it" a second time and have surface area to be able to reapply the chemical. This time you can and probably should use the concentrated form of BrushBGon.

Kannapolis, NC(Zone 7b)

That's hilarous! I agree, I know I can get a little 'lordish' with my plants as to who lives and who dies! It's good to have a reminder of whose really in charge!

Dallas, TX(Zone 8a)

Yep Nicole, I think I reign supreme in my yard! :)

Thanks for the tip Equ- I will add that to my arsenal!

Monticello 4, IA(Zone 4a)

I am really dense sometimes so forgive me please? In your posting Eqi - you said " Donít let your trays dry out. Don't over water and keep your saran wrap in place until you see green. Then remove it so air can circulate better."

I just wanted to confirm that you get the tray, put holes on the bottom, spread your medium, put the seeds on it, put the saran wrap over all and then stick it outside in your garden until next spring? Am I right? I have some Baptista seeds that would benefit from this method if only I can get over my panic :)

God bless!


Hi Mindy, sounds like you'll be just fine. Now remember not to be too hard on yourself if it doesn't germinate as there are many variables. Children and pets come to mind. Overall, I'm thinking this is the best way to go. Now your seed isn't Baptista though. You've got Baptisia. If you were trying to do a search to get information the misspelling would throw you off. Great native plant. If it doesn't germinate for you, get back to me next year and I will get more seed for you to try again. I have both the white and the blue flowering but not the cream.

One thing... you need to put a rubber band around the outside to hold the cellophane in place for at least the coldest of the months. They will go boing after a month or so. Add another one. That one will probably go boing too. After a few go boing enough, it'll be spring and soon thereafter you should see sprouts.

Also too, don't forget to cook your planting medium.

Have fun and go get a few more seeds to play with!

waukesha, WI(Zone 5a)

What a great thread! I'm going to try this this winter. I have NO success at starting from seed indoors, and this will be a fabulous way to use all those seeds that have been stuck in a kitchen drawer all summer. What have I got to lose? Plant 'em, plop them out in the garden beds along the house, and let nature take it's course. I'm actually excited to try this. WOOHOO!!

Hi weezersfive! Let me know if you have any issues too. This really does work! Have fun!

Kannapolis, NC(Zone 7b)

Ok E (can I call you E? :-) I have been wondering if something would work.... How about sewing in my garage? I have a table and a window and grow lights. Would it be too cold for say - tomatoes and annuals? I know the 2 of us are in vastly different zones.. I start my tomatoes no earlier than 6 weeks before last frost.

Anyway, it would be nice to have all that stuff out of the house b/c it's messy and takes up so much room!

I think I already know the answer you are going to give though :-(..


Hi Nicole! I do not know the answer as I have never winter sown annuals. A garage is perfectly fine normally for many activities though. Try it and you tell me how it goes! Better yet, isn't there a vegetable forum here somewhere? What about posting over there? Gosh, this sounds like the possibilities are endless! I'm really thinking you shoud definitely try this! Bye for now, Lauren

CREZIERES, France(Zone 8a)

I think that Equilibrium's original post is just great, and a really useful guide.
However, going back to the original question, the point about whether seeds need warm before cold is one that might be commented upon.
In this regard, the best way of figuring the best way to sow is to think about how the plant fares in nature. If the plant in the wild sets and drops its seed before the onset of winter, it is a good idea to give the seeds some time in the warm before chilling them. It shouldn't normally be necessary to give them the full 90 days if you know that they do not germinate in the warm. I reckon a month in the warm will help most (but not all) winter germinators.
The second thing worth mentioning is that one should always consider the possibility that light is a necessary condition for germination, and fluctuating temperatures may also be necessary.
A very good site is this one from the Ontario Rock Garden Society which integrates the great work of Prof N Deno with the experience of their members.

Oh great link for Alpine plants! I am bookmarking that! Thank you!

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