Winter Sowing Milkweed Seeds Part 2: Prepare Your Containers

Now that you’ve gathered your containers and secured your milkweed seeds, it’s time to set your seeds to soil. Follow these 11 simple steps, and then patiently wait for Father Winter to take a Spring Break.

If you haven’t gathered your winter sowing supplies, take a couple minutes to Read Part 1 which discusses containers and other tools you will need to start.
How To Winter Sow Milkweed Seeds: 11 Simple Steps for getting Old Man Winter to Stratify your Seeds so they'll Sprout come Spring.

After researching containers from the last post, I’ve decided to use distilled water  jugs for containers. I chose this option because they are roomy, cheap, recyclable, and easy to cut through.

We are using more 2 Liter Soda Bottles and similar clear containers because the opaque milk jugs have had some issues with mold and moss in wet springs. The process for preparing the containers is the same…

You also won’t need to cut air/moisture holes in the top of these containers. Just throw away the cap and you’re set! Gallons of distilled water are widely available at many stores for less than a dollar.

If you’re using another container type you may need to make some minor adjustments. Let’s get sowing…


STEP 1: Rinse Your Containers

Thoroughly rinse out your containers of any remaining food or beverage.

STEP 2: Label Your Containers

Use a permanent marker intended for outdoor use so your label won’t smudge or rinse away. Mark on at least two sides.

STEP 3: Drill Your Holes

Remeber to put drainage holes on the bottom of winter sowing jugs so there is adequate drainage for germination and healthy seedlings.
Cut and Poke

Drill 4-8 holes (use a drill bit for plastics) on the bottom of your container for drainage. The holes should be approximately 1/4″ in diameter. Drill more if the holes are smaller.

We are doubling the number of holes in the opaque milk jugs and using a lighter seed starting mix to increase drainage. This will (hopefully) prevent future mold and moss issues.

No drill? Try using a box cutter/scissors/knife to puncture the plastic and then stick a phillips screwdriver head through each hole.

If you use containers with lids (e.g. plastic fruit containers), you will also need to cut a few holes in the lid.

STEP 4: Trace A Line

Use a marker to draw a line around the entire container. The line should be drawn at least 4″ from the bottom of the container.  Use a ruler if you need one.

STEP 5: Cut Your Container

11 Steps for Winter Sowing Milkweed Seeds- After tracing a line about 4 in. up from the bottom of your jug, use a box cutter to cut around 3 sides of the jug, leaving one side attached as your hinge. Don't include the jug handle as your hinge because it will make your container more difficult to tape shut. See the other 10 steps here...
Don’t Include Handle on the Attached Hinge

Use a box cutter or scissors to cut along the line you just drew. Cut just three sides, leaving the remaining side to act as a hinge when opening/closing the container.

Don’t use the ‘handle’ side of the jug as your hinge. It’s harder to keep the container open and to tape it shut.

If you’re using 2 liter soda bottles, leave about a 1″ hinge when cutting the container:

If you're using soda bottles for milkweed sowing containers, leave about a one-inch hinge when cutting the container. More info on winter sowing...
Soda Bottle Winter Sowing Container

STEP 6: Add Potting Soil

Use a regular potting mix that’s also intended for starting seeds. Do not use a moisture control mix that could negatively affect germination. Add at least 4″ of soil.

STEP 7: Wet The Soil

Wet your winter sowing container soil before planting your seeds
A Kitchen Sprinkling

Saturate the soil using a lighter sprinkler setting with a hose, watering can, or even the hose attachment on your kitchen sink. Using a high powered hose can compact your soil. Use trays or pot saucers to capture water coming through drainage holes.

Use an Outdoor Marker on a Plant Label INSIDE your Winter Sowing Containers . In spring, you can plant this label with your new milkweed patch.

Notice the plant label inside the container. When the lid is closed this fits up inside the handle. This is insurance in case your other labels get smudged beyond recognition.

You can also use the label when you plant your seedlings next spring. (Be sure to write on the label with your weatherproof marker!)

STEP 8: Sow Your Seeds

Winter Sowing Asclepias viridis seeds- you can broadcast seeds or plant in rows. If you have extra seeds, broadcasting will likely give you more plants to choose from.
Sowing the Seeds of Love

You can either place, sprinkle, or broadcast them depending on how many seeds you have. After they are sown, lightly press each seed into the wet soil so it stays in place.

STEP 9: Scatter More Soil

A light coating of soil over your seeds will suffice, around 1/4″

STEP 10: Close The Container

Keep winter sowing containers secure all winter with, what else? Duct tape!
All The Way Around!

Make sure you secure the entire seam with duct tape. If the container is compromised your winter sowed milkweed could become an epic fail!

STEP 11: Set Your Container(s) Outside

Follow these 11 Easy Steps for Winter Sowing Milkweed Seeds and then patiently wait for Father Winter to take a Spring Break. Seedlings should sprout earlier than average protected by their mini-greenhouses.
Hibernating for Winter

Put containers in a spot that gets at least a few hours of sun, and won’t be disturbed by pesky animals or rambunctious kids. Leave the caps off your containers so the milkweed seeds get natural watering from mother nature.

Are They Secure? If your containers are in an area where they could blow over:

  • tie the handles to the fence with long cable ties or twine
  • put rocks, bricks, or pavers around the containers
  • put a plastic/metal stake through the handle into the ground
Place winter sowing containers in a secure area that gets plenty of sun. Use rocks or bricks to keep containers in place. 11 simple steps for winter sowing milkweed seeds.
Use Rocks or Bricks to Secure Containers


You won’t need to water over the winter. However, once your seedlings start growing in spring you should make sure there is visible condensation when looking at the jug. If not, lightly water through the open hole.

In spring, dig the container slightly into the soil. Then, water the soil so that water can come up through the bottom drainage holes.

What’s Next?

Barring disaster, when spring comes it will be time to remove the top half of your container. You may also need to move the container to a different spot for more/less sun exposure. Until then, enjoy your natural cold moist stratification!

See Comments Below about Winter Sowing Milkweed Seeds for more info…
Share the Joy of Butterflies

Similar Posts


  1. I winter sowed several milkweed varieties in containers and other wildflowers in February (2018), I live in Minnesota. We had a really cold and snowy spring, the wildflowers are just coming up but not much happening with the milkweed. Planted several milkweed varieties indoors a couple of weeks ago, having more success with those planted indoors. Anyone else from the upper midwest winter sow? What has been your experience this year?
    Best Wishes!

    1. Hi Ron, I’m in Minnesota too…we typically winter sow a few milkweed containers but did not this season. A lot of things are running late this spring, so I’d wait a bit longer before giving up. I’m glad you opted to expand your propagation methods…just in case! If your seedlings decide to make an appearance, here’s more info:

      Springing Your Winter Sown Seedlings

  2. We live in Virginia and I just saw this. Is it too late to sow these milkweed seeds now? If not, please advise for best results. Tia

    1. Hi Denise, 3-4 weeks of wintery weather should suffice…For your region, I would get them going as quickly as possible or try cold moist stratification in your refrigerator instead…or perhaps try both so you don’t put all your seeds in one basket…good luck!

  3. First time winter sowing, but on Sunday (Feb 04, 2018) I planted these milkweed varieties:
    Prairie Milkweed – Asclepias Sullivantii
    Common Milkweed – Asclepias Syriacas
    Tall Green Milkweed – Asclepias hirtella
    Whorled Milkweed – Asclepias verticillata
    Showy Milkweed – Asclepias speciosa
    Purple Milkweed – Asclepias purpurascens

    Also sowed these non-milkweed species:
    Wild Bergamot – Monarda fistulosa
    Cup Plant – Silphium perfoliatum
    Giant Hyssop – Agastache scrophulariifolia

    The purple milkweed seeds are expensive but from the pictures I see on line it looks like a beautiful plant.

  4. Hi Tony!

    Do you think it matters if the clear soda bottle is colorless, versus the transparent green color of, for instance, a ginger ale bottle, or any other colored but transparent bottle? Or does it need to be transparent AND without any color?

    Thanks for sharing your experience and insight with us!

    1. Hi Carolyn, I’ve used colored (green) bottles before and had success. I’ve had the most success with the clear bottles, but I’ve also had some success with the opaque jugs…we’ve had more success overall since using the lighter seed starting mix.

  5. It’s the day before the Super Bowl and since I’ve gotten a late start, the Swamp Milkweed seed has only been in the frig for a week, however the seed was in the freezer about three weeks prior. (I’m now rethinking that storage method). I was planning to start the seeds indoors and am wondering when I should do that (S. Central MO). Also, I’m confused about the Super Sow. Do the seeds still need a period in the frig before setting in the milk jugs or does this serve as a natural stratification? I have extra seeds and a milk jug so I can give the outside start a try. Really appreciate your help. Since I have to mow the pasture for the horse and mule, the milkweed has disappeared and would really like to get a designated spot growing again. Thanks!

    1. Hi Ruth, the winter temps/precip provide a natural cold moist stratification for your seeds. good luck!

  6. Hi Tony, I had a tropical milkweed stem with roots in water last winter in a cold porch. I had a mother in laws tongue in with it, got too tall and fell over, hoped it would re-root. My 1st butterfly season ended on a tough note after collecting leaves I thought was safe. I was surprised when I saw it had sprouted leaves over the winter and replanted it in my garden in spring. It did well and bloomed late in the year.

    I think the decomposing m-i-law stem may have provided nutrients.

    I dug up more late last fall and have them in a couple water jugs in attempt to recreate. Note- the rooted stems are from my garden with no chemicals. I had a shortage, which was my reason for leaf collecting.

    I am in SE WI, any thoughts, concerns?

    Thank you!

    1. Hi Anita, my only concern would be that you’re thoroughly rinsing the plants if you’re reusing in case there is an issue with pathogens. good luck!

  7. Hi Tony,
    I planted about 100 milkweed seeds yesterday around my pool anchoring them to the fence.
    The neat thing is being new at this l have no idea what type of milkweed l planted .
    I’m sure most of it will be Ascpepias Syriaca as l live in Southern Ontario, Canada.
    And all the seeds were harvested locally be myself.
    I also have a few hundred seeds for spring planting. I also planted some in the fall.
    And I have bought 200 seeds of tropical milkweed for planting this spring.

    1. Hi Brian, it sounds like you will start growing a healthy crop next season…good luck with your new butterfly garden!

  8. Hi Tony,
    I enjoy the newsletter that comes to my email. I currently have 15 milk jugs on my deck that contain winter sowing, 3 of them contain milkweed seeds.

    I have been unsuccessful in my search for Red Ring Milkweed seeds. Can you please notify me if you find a source?

    Thanks in advance!

  9. I live in Minnesota. I collected common milkweed seeds last fall, dried them and have had them in a plastic baggie in the refrigerator since then. Rather than winter sowing the seeds, can’t I just plant them in seed starting pots and place the pots in a sunny window in early spring?

  10. Last year, I put seeds in Zip-lock snack bags with a damp paper towel and put them in the fridge for a month. (common MW, swamp MW, and honey vine) Then took them out and planted them in flats in a warm place under fluorescent lights and got very good germination in about a week. I use half-gallon milk cartons cut in half lengthwise for flats, until the seedlings are ready to move into little individual pots.

    I’m starting the little bags today for this year’s crop. Milkweeds and Joe Pye weed.
    Probably should have started a week ago…

    I like the clear pop bottle with the hinged top idea. I might do that for the Joe Pyes because the seeds are small.

  11. @Dana: (I can’t tell if the link to reply directly to your post is working) that Miracle Grow potting soil will work great if you mix some sand with it. About 1/3 sand and 2/3 potting soil, or maybe even more sand than that. I can’t give you and actual ratio because I just put handfuls in until it looks right 🙂 Good luck!

  12. Can you broadcast the seeds looking at doing a few acres

  13. I’m in So. Cal and some of the butterflies stayed here. I had 12 caterpillars in January. It took longer to firm the chrysalis and it took 14-15 for the butterflies to emerge. All 12 were released. No new caterpillars, but I have very little milkweed.

    Last year my milkweed seeds didn’t grow well. I bought seeds from a different source and the instructions said put the seeds in the refrigerator for 6 weeks. That’s where they are now. I hope i have better luck. It got hairy at the end of the season last year because I had very little milk weed left in the fall. I found that the caterpillars will eat butternut squash in the 5th instar stage. I’ll try that this year. I released close to 60 Monarchs last year, my first year.

    1. Hi Susan, because of the extra rain in many regions of California, you might find more success growing milkweed this season. If possible, it’s a good idea to focus on establishing a good milkweed supply before raising, but, I realize sometimes the monarchs have other plans. good luck!

  14. Hi Tony, Us southern climate zone (8b) folks have to rework the winter sow rules with our short winters. I was scheduled to present Milkweed/Winter sowing for our Master Gardener group the first of January and wanted to have some sprouted plants on hand so I got them ready in October. Milk jugs, soil, seeds, tape and the whole deal and deposited them in our daughters spare refrigerator. I took them out Christmas Day and they were sprouted in three days. Of course we had a warm spell of 70s that helped. The seeds I used were the varieties that need stratifying so it worked out perfectly for me this time. I have since put out some asclepias tuberosa, and asclepias tuberosa gay butterflies without stratifying and they sprouted quickly in their safe little jugs. I donated most of the plants to the Botanical Gardens pollinator garden, and they were thrilled to get them.

    1. Hi Alice, cold moist stratification increases the germination rate of many milkweed species, but the viability of the seeds is more important…I’m glad to hear of your seed success, even if things got started a little early for you.

      I’m in Minnesota so while much of the information I provide is relevant, it must be adjusted to fit your southern climate. Good luck with your garden…

  15. I am a retired teacher/volunteer/Green School Coordinator at St. Mary School in Mt. Clemens, MI. I help two school teachers at St. Mary School with the monthly Ecology Club meetings. I am excited to help the teachers with winter sowing common milkweed seeds Monday, Feb. 6. Kids will plant the seeds in 2 liter bottes, two students to one bottle. Then we will place the bottles outside in one of many school gardens. We have several swamp milkweed plants in school gardens, but this is the first time we are planting in bottles and using common milkweed seeds. I collected milkweed seeds in a local park a few days ago so the seeds have had some cold stratification already. I am hoping the seeds sprout and that the kids can successfully plant the plants in a deep raised bed I hope to have a volunteer build for the school. Thanks for the awesome tips. I am so excited to do this.

    1. A fantastic school project idea, Regina! When spring planting, I would suggest giving the common milkweed its own section in the garden. It spreads through underground rhizomes, but swamp milkweed does not. Good luck with the school butterfly garden!

      1. We have a swamp milkweed bed already, i plan on finding a volunteer to build two deep raised beds for the common milkweed. We will line the beds with landscape fabric and plant the common milkweed plants. Hoping it will work without spreading rhizomes everywhere.

          1. This is so cool! I, too live in Mt. Clemens, Mi & did the winter sow suggested here for Butterfly Weed since I’d been stupid all these years & just broadcast Milkweed seeds all over my gardens. I had none left & It never worked until last year,

            I finally got one(Milkweed)! I was really excited but it’s growing in my front garden in an azalea bush & nothing is nearly as tall! Lol. I was just so happy to finally get one, I left it alone…

            I began mine 1/29/17. We didn’t have much of a February like we usually do, but it seemed like it was cold enough to get the job done. Well, here it is April 9th & I have zero germination! Again! I used all clear bottles as suggested with just one milk jug. I saw moisture collecting on the sides of the bottles & everything was looking great.

            Now, the weather is warming, shouldn’t there have been 1 plant? I have 6 jugs of 5-6 per jug. They aren’t steamed up anymore- should I begin watering myself?

            Judi Gambaro

  16. Hi Tony. Just planted six different mw seeds in different gal. jugs. My main concern is the sun. Does it matter during the winter months if they get sun light all day ?? I live in NE Indiana. Also, it will be in the thirties this coming week , can I still go out and start some in my garden ?? Thanks

    1. Hi Ernie, I’m not sure that it matters. You do want to make sure they have more light in the spring so they germinate and grow. Also, if you can dig into the soil, you can still plant seeds in your garden. good luck!

      1. Hello Tony. Can you start to stratificate the seeds in January in New Mexico? Also, I didn’t do the stratification process this winter here so I was wondering, could I just stick them in the refrigerator, and how do I do so? Thanks

  17. Hi Tony,
    Just curious…if the swamp milkweed are planted in the plastic containers with only 4 inches of soil. Do they stay in those containers all summer?

    What happens when they really get going? The roots are the long ones which like to go deep, I think, correct? Does being in a shallow container stunt their growth or do you transplant them come warmer weather?

    Thanks, Marilynn

    1. Hi Marilynn, you don’t have to worry about taproots with seedlings….it’s the mature plants that would cause issues. Swamp milkweed (A. incarnata) does not have a tap root and doesn’t spread aggressively like common milkweed can. Swamp milkweed makes a good container plant, but any species with underground rhizomes are better for direct planting:

      Growing Milkweed in Containers

  18. Hi Tony,

    I’m curious…and always looking to experiment. What would happen if I cold moist stratified just a couple butterfly weed seeds for a month or so then planted them inside, letting them grow over the winter in here and planting them in the garden in the spring (I live in New Jersey). I’m not joking…just inexperienced and experimenting.


    1. Hi Sheila, you can always try, but I’m not sure how that will affect the growth cycle during the season. Tropical milkweed doesn’t matter as much because it’s a continuous blooming plant. If you like to experiment, see what someone in our community did with the butterfly weed seeds at the bottom of this page….it works!

      An alternative way to start Asclepias tuberosa seeds (scroll down to the bottom of the page)

  19. I live in Iowa if I get my seeds sowed by November is that soon enough or too early?

  20. Hi Tony. I have several containers outside using the winter sowing technique, which was very successful in 2015. I just acquired some other milkweed seeds that need stratification. Given the strange weather here in SW Michigan, I’m wondering if it is too late to winter sow. Should I stratify in frig or freezer for 30 days, then plant in the jugs, or trust that if I plant them today they will have enough cold weather for the stratification. We have 10 inches of new snow today, but temp will rise to 40’s this weekend. The temps have been so up and down this winter. Does stratification need to be below freezing for 30 days, or just cold like a frig around 40 degrees?
    Thank you for all your info. Mary Ellen

  21. Tony,
    The stratified butterfly weed seeds planted on Feb 4th are germinated and growing still waiting on the white and pink swamp milkweed seeds to germinate. Just a little late with the supersow sunday sowing but did get 10 asclepias asperula and asclepias viridis seeds planted today with your expert tips.
    Thanks for all you do for the Monarch movement.

    1. Hi Brian, as long as the seeds are cold treated for at least a month they should be good. Seed quality is more important than a prolonged cold treatment…good luck with your winter sowed seeds and indoor seedlings!

  22. I grew milkweed up in New Hampshire. But I have now moved to The west coast of Florida. What kind of milkweed should I use down here. Do you know where I can get the seeds or plants. Last year while visiting down here I brought a plant from a butter fly estate. It had one egg and then a monarch visited and I ended up with 20 eggs. When is the good time to sow seeds or get plants. It was so neat watching them grow and then fly away. Thank you for your help.

    1. Hi Joan, here’s a resource with plant ideas for your region:

      South Florida Butterfly Plants

      you can also check out my milkweed resources page, which lists that native and perennial regions for each milkweed species:

      Milkweed Resources Page

      For Florida gardening specifics, I would visit a local nursery or contact the master gardeners extension program in your region. good luck!

  23. Is it to late to throw seeds out in a feild? I have 2 places that I wanted to try to seed, but I am not going to be able to dig or transplant do to physical limitations.

  24. I still haven’t been able to find any milkweed seeds to buy…..I’ve tried various websites but since I don’t want to buy thousands (not yet anyway)….no response… Any suggestions?

    1. I found a seed company just a few miles from me in St. Louis, MO called Seed Geeks. Bought a packet of Swamp Milkweed seeds. I plan to sow them in the swamp garden next to the pond next weekend (Feb 20) since it’s supposed to warm up to near 70 degrees. Hoping to see some sprouts in May.

  25. Hi Tony, I believe Holli sent me some Harry Ball MIlkweed Seeds, when would IPlant them ?

    1. Hi Judy, G. physocarpus doesn’t require cold treatment. I only soak the seeds in warm water 24 hours before planting to increase germination speed. I start the seeds indoors about 2 months before avg last frost…here’s more info on balloon plant:

      Balloon Plant Milkweed

  26. When spring comes & it’s time to transplant these guys –milkweed–after winter sowing how do you move them to their new site. Do the roots stick to the milk container or are they pretty solid? About when do you move them to their new sites. I have to ask these questions because I live in area 7 & regrettable by the time you get your pictures & e-mails out our season is a few weeks ahead of yours.
    As always thank you for the your articles to inspire us to help bring back the Monarchs. While I don’t get out much my facebook friends are getting informed about Monarchs from my posts.

    1. Hi Nancy, I am adding more to part 3 this season, but if you look at the third photo down on the linked page, I let the seedlings grow about a couple inches more before removing:

      Winter Sowing Seeds Results

      I waited because I generously scattered the seeds, and didn’t want to remove seedlings until most of the seeds had germinated.

      Because they were growing outside, the stems grew sturdy in the spring breeze. I let the containers dry out (slightly) before removing the entire mound of dirt from the container. It was surprisingly easy to separate the plants at soil level. The soil was almost fibrous was all the root growth

      If plants are growing on top of each other, you can try to unravel the roots or just pinch one plant off at the base.

      Again, I will be adding more tips to these articles as I start winter sowing process this season…

  27. Could I just direct sow during warm fall and cover bed for wintering??? Bed has good drainage and good afternoon/evening sun for a few hours. I’m in zone 5b and its 70 this week but drops next week.

  28. I live near wooded wetlands in Virginia; can I directly
    plant the seeds now?


  29. Hi Tony,

    I did try to order species that allegedly might grow well in the Midwest. I have things winterizing outside in cartons, and in the refrigerator on damp paper towels.

    Ascelepias speciosa – Showy?
    Oxypetaum caeruleum – Tweedy?
    Ascepias Incarnata (Can’t read the label now) SWAMP
    and Asclepias Cinderella.

    I ordered them from Georgia Vines
    I also just received two Butterfly bushes from Arkansas, and we are getting a grow light for anything that needs protection.

    We are NO WAY clear of winter in Illinois (Chicago area) yet.

    I will study the other info you sent.

    My husband is SO hoping we are able to get this going. He also puts out preying mantis cocoons every year.


    1. Hi Denny, I’m not sure how tweedia will respond to cold stratification, but it doesn’t hurt to try.

      The other two varieties should respond well to the stratification.

      Keep in mind, mantises eat butterflies so I wouldn’t release masses of them into your garden. Good luck!

  30. OK all of you experts! This is our first year trying to raise milkweeds. We ordered more exotic kinds because the so-called Landscapers in our complex seem to recognize common milkweed and despite our little fences and signs, rip it out of our tiny garden.
    Perhaps if we can get other varieties started we can trick them into viewing them as flowers.

    I have seeds in the fridge, and seeds outside in milk cartons. I went half and half on winterizing seeds. Looks from your website like the ones outside just follow their own course. Should I take the refrigerated ones out and plant them inside with a grow light? Looks like that might be our next step. They have been in the fridge for almost a month.

    We had exactly ONE observed monarch butterfly in the yard last year but hoping to attract more.

    We live in N. Illinois where it is definitely NOT yet spring.

  31. I have been winter sowing flowers and herbs for several years. I wondered if milkweed would successfully winter sow, but could not find any information. Thank you for the article.

    1. Hi Barbara, most milkweed varieties need cold stratification so winter sowing is a great option for many. Good luck with your seeds!

  32. Hi Tony,
    What a clever and great idea. I have hand sown some seeds and have some chilling in the fridge and am going to give this one a try also. Do you think it would work if I used the 6 packs from annuals for winter sowing? Would I need to cover them?

    1. Hi Chris,

      yes, you would need to cover them. You could even try covering with a plastic baggie if you put some slits in it…or attach an upside down plastic cup on top of a right side up one. There are lots of makeshift ideas you can try as long as the containers can get moisture and the eventual seedlings are protected from extreme cold.

  33. I really like the idea of Super Sow Sunday. I’m in Zone 7, so hopefully this will still present enough of a cold season to stratify my seeds.

    1. That should be fine Erica. I’m not sure who decided seeds should be stratified for 3 months. I only cold stratify 1-2 months at most, and that’s worked well for me.

  34. Hi Tony:
    Great information about Winter sowing. My questions are…….1. If using a plastic milk gallon as a container, how many seeds would you recommend sowing in that space? I ask this because I don’t want to disturb roots/rhizomes when transplanting. My seeds are from the Monarch Waystation. I have Butterfly, Swamp and Common. 2. I believe that placing the containers on the deck which receives morning Eastern light should be alright?

    1. Hi Susan, I actually plant my seeds intentionally, but other people just broadcast them over the soil and then thin them out later…that might be the smarter way if you have extra seeds…that should guarantee more seedlings and you can thin them out later by pinching off unwanted seedlings (not pulling them). As for lighting, they might grow a little faster if they were in more sun, but most milkweed doesn’t won’t fully mature the first year anyway. In partial shade, you don’t have to worry about accidentally frying them…

  35. Tony,
    I have a ton of tropical milkweed growing here in NW Florida, I am thinking about now is the time to prune and root it. Does that sound about right? Cheryl

    1. Hi Cheryl, since you have an abbreviated off-season in North Florida, I think now sounds like a great time to cut back your tropical milkweed and also start new cuttings.

  36. I have several varieties of milkweed. Only tropical is in greenhouse for germination.
    The rest I planted in black 4inch plastic pots and some are bigger. I have them outside, not covered. I am in east tx. zone 7a. Do I need to do this differently?

    1. hi Judith, my concern would be that soil could easily dry out in 4″ pots. Leaving the pots uncovered will make them dry our even faster. Since you already started, you might as well keep going. Just keep a close eye on the water situation so your soil doesn’t get bone dry…good luck!

  37. I am new to planting milkweed as well and have 2 questions I hope you can answer. I saved some common milkweed seeds from the fall but I may have wasted those precious seeds because I stored them in the freezer rather than the crisper, did I ruin them? I also scattered some seeds rather than planted them. I read an article that said that does not work well, did I waste them as well. Thank you for your help.

    1. Hi Janet, I’ve never stored seeds in the freezer, but I think the seeds should still be viable. It gets colder outside then it does in the freezer and plenty of those seeds still germinate. If you stored a warm weather variety like tropical in the freezer, I would suggest getting new seeds. If they’re perennial seeds in cold regions, you should be fine. Keep us posted!

  38. Ok. Got it. Done. Now what? When do I plant??? Average date of last frost??? When seedlings are a certain height??? Help a first – timer!

    1. Hi Jessica,

      I’m posting this series in real-time….we just had a few inches of snow yesterday so the next article might be awhile. Once the seedlings start to sprout make sure the soil doesn’t dry out. Has the inside soil turned light brown(dried out)? If so, it’s definitely time to water. As they grow and temperatures moderate, you can cut a hole on the side of the jug so there’s better air circulation and more sun exposure. If temperatures go below freezing put a towel over the jug to cover the side hole. Once the threat of frost is over, you can remove duct tape from the jug and remove the entire top half giving your plants full spring exposure. They are ready to plant at that point, but if you’re worried about seedling damage from kids/animals you can keep them in the container for longer. I’ll be posting about this in detail later…

      1. Thanks! I’ve got some seedlings from the seed packets I ordered from Monarch Watch but the ones from seed pods haven’t sprouted. Is there a different way to deal with dried seed pods? Or maybe it was just those containers didn’t work as well . . .

        1. hi Jessica, did you collect the seeds after the seed pods opened or were they still shut. Are you currently winter sowing? If so, where are you located?

  39. Tony,
    Another germination from Super Sow Monday. One of the Antelope Horn seeds germinated and am so excited. Yes, I am using a heating mat. We finally made it above freezing two days this week how nice. I found that the perennial milkweed seeds that I stratified are germinating better than fresh tropical milkweed seeds are this year. Take care and may you have had your last cold and snowy blast. Thanks for all the great ideas that you have to help the monarchs.

    1. Hi Brian, just one seed? It’s my understanding the germination rate on those is lower. I winter sowed mine and direct planted a few last fall. Hopefully more will germinate!

      As for tropical, the germination rate on those is usually pretty high if you soak them in water overnight and use the heated seedling mat. A couple of theories 1. My worst germination rate for tropical was when I harvested seeds from aphid-infested plants 2. Soil temp might not be warm enough yet

    1. Hi Malcolm, I have never had used antifungal or rooting hormone on seeds. Our seeds have always had high germination rates. Is there a particular species you are having an issue with?

  40. Tony,
    Have a purple milkweed seedling growing in the basement hope a few more seedlings appear soon it was from the sowing of the Monday after Superbowl sowing. There were 6 seeds from Georgia Vines so I am hoping for at least 2 more seedlings. I really love the color and bloom of the purple milkweed. Am afraid I may have over stratified the antelope horn seeds but will keep and have a few of the tropical milkweed seeds also germinating. Looking for a week finally with above freezing temps it has been too long. Yeah rah Feb is now half over also..
    Brian from Ossian

    1. Hi Brian, thanks for your updates!

      What do you mean you overstratified the antelope horn seeds? I had a horrible time starting purple milkweed seeds last year. I started them indoors and their soil was too moist (I think). I ended up taking them from the container and direct sowing in spring…two of them germinated so I’m hoping for at least two plants this spring. They are pretty close to our common milkweed patch so I’m wondering if they will hybridize…

      Too bad you only have 6 seeds…would be interesting to do an experiment between winter sowing purpurascens outdoors and starting seeds inside. Keep us posted…

      PS Are you using a heated seedling mat? That usually speeds up germination.

  41. Tony,
    Great idea for Super Sow Sunday. I did the sowing today instead of yesterday and planted the seeds of A. purpurascens and antelope horns that I had in the refrigerator for the past 2 months and planted some of the Tropical seeds from my cousin in FLA. Since I had pretreated the perennial seeds I just planted them in pots and put them down in the basement under growth lights and also giving one set of pots the small amount of warmth from a tiny seed tray warmer.

    The October planted tropical ones are looking good and about 4-5 inches tall now and added some of the natural sea weed tonic to see if they would perk up some. Sorry to hear that the monarch population is still down 44%. Have you heard if any of the Monarchs that you tagged have made it there or not? Brian in Ossian

    1. sounds like you have a great head start on 2014 garden season. If your tropical plants are getting leggy, try putting a small fan on them to simulate the natural breeze it would receive outdoors…this strengthens stems and keeps seedlings from leaning.

      Brian, I did not tag this past season but plan on doing it in Fall 2014 for Raise the Migration 2… BTW- the population is down ANOTHER 44% from last year. Yikes!

  42. I start all seeds in clear plastic jugs and cut them the same way. This will be the first time I do this in February and put them in the snow. Does anyone know if the opaque jug is better for this seed?

    1. Hi Barb, I think you will probably be fine with the clear containers. I am using the milk jugs because it seemed like the majority of people I’ve talked to (and from researching online) have preferred using the gallon water/milk jugs because they are the easiest to set up. If you have extra seeds, why not try both and see if you notice a difference in your results? Please keep us posted on your progress!

    1. Hi Carol, I will be posting more about this in ‘real time’ so I’m able to show you the results and next steps. Most milkweed varieties have rhizomes that spread to some extent. The only two that I regularly hear people complaining about are Asclepias syriaca (common milkweed) and Cynanchum laeve (honeyvine milkweed). Can you think of others?

      Showy Milkweed and Purple Milkweed both spread through rhizomes but are a good ‘replacement’ option for common because they are more manageable in a garden setting. I’ve got showy, common, and purple milkweed all within feet of each other. I wonder what strange hybrids will evolve in the coming years 🙂

  43. where would be the best place to get some milkweed seeds, all I have are the wild ones and I would like to have some that do not grow so large and heavy that they have to be staked.

    1. Hi Ethel, on my resource page I have info and purchase links to around 15 varieties(and more coming soon)…if you scroll to the bottom of the page there are also milkweed stores that I personally buy from:

      Milkweed Resource Page

  44. This is my first year wintersowing. I just read your “Wintersowing Milkweed Seeds Part 2…” When I read this, “Do not use a moisture control mix that could negatively effect germination.” my heart sank. I used Miracle Grow Moisture Control. What does “negatively effect germination” mean exactly? Will these seeds not germinate? Thanks for your help.

    1. Hi Dana,

      many milkweed varieties will have lower germination rates if the soil stays too wet. (Swamp milkweed would be an exception.) You still have plenty of time to make a course correction before monarch season begins.

      The biggest issue I’ve heard regarding moisture control soil is that it doesn’t drain very well, which can be a problem if you have above average precip.. You could try putting more holes in the bottom of the container. However, if you have extra seeds I would also add some new containers with a regular potting soil. I hope this helps…

    1. Hi Wilma, winter sowing will work with any milkweed species that requires cold stratification (which is most milkweed varieties). It is not necessary for warm weather varieties including tropical, swan, or giant milkweed.

        1. Hi Kali, I don’t see any reason why winter sowing your “garage” seeds would be a problem…were you planning on starting them another way?

    2. If by “regular milkweed,” you mean Common Milkweed, it does not require cold moist stratification. You can sow seeds outdoors after the threat of frost has past, or get a head start by germinating them indoors earlier and transplanting small plants outside when frost is past.

      1. Hi Donna, I’m sure some common milkweed seeds will germinate without stratification, but the germination rate will increase with cold stratification. However, I don’t use paper towels or sand to moisten the seeds….dry seeds in a plastic baggie inside another container.

  45. Thanks! Great ideas. Now I know what I will be doing this week!

Comments are closed.