Growing milk weed seeds

Fall Planting Milkweed Seeds: 10 Simple Steps!

If you’ve been thinking about planting fall milkweed this season, November is the best time for most of us to complete this simple garden task. It’s too warm for the ground to be frozen but too cold for seeds to sprout before winter sets in.

Fall planting is a great way to get your perennial milkweed varieties started, since the seeds will need cold stratification…and Father Winter takes care of this naturally! Consider planting milkweed varieties that are native to your region for best results.

Why is fall planting milkweed a good idea? Exposing seeds to cool temperatures before the warmer temps of spring will cause them to break their dormancy coaxing out your new spring seedlings. It also saves you the hassle of in-home stratification.

Warm weather milkweeds, which are annuals for most of us, do not require this cold treatment. These varieties include tropical milkweed, swan milkweed, goose plant, and giant milkweed.

If you still need to collect milkweed seeds from your garden or local milkweed patch, check out this article to how to harvest milkweed seeds.

If you are buying seeds from a vendor, they should have instructions telling you whether cold stratification is necessary. If not, search for specific milkweed pages on this site or consult with Mother Google.

10 Simple Steps for Fall Planting Milkweed

1. Put your seeds into a small bowl and bring out to planting area. Find seeds here if you still need to buy some.

2. Clear away any mulch or rocks from the area which could potentially block the growth of a small seedling.

3. Water the area thoroughly and let it saturate the soil.

4. Put on garden gloves and stick your index finger in the dirt up to your first knuckle.

5. Repeat this process for each seed you are planting.

Measuring between holes: Make the letter L with your thumb and forefinger. Use the distance between the tips of each digit for approximate spacing. Seeds can move over winter and some won’t germinate so exact spacing now is a waste of time.

6. Place a seed in each hole.

7. Cover the seeds with the already-moist soil. You can place a few inches of straw or leaf mulch over the area to keep the soil from drying out.

Be sure to use a weatherproof garden marker (intended for outdoor use) so your labels don’t rinse away over winter.

9. SQUIRRELS? Consider putting down chicken wire to deter squirrels or other pesky critters from digging up your new milkweed patch. You could also put off planting until just before the ground freezes or before your first major snowstorm.

10. Relax for the winter.

11. 1-2 months after your seedlings have sprouted next spring, pinch off extra plants (or consider transplanting) to achieve ideal spacing for your specific milkweed. The Ascelpias viridis (spider milkweed) plants will be spaced 1.5 to 2 feet apart.

If you miss the window of opportunity for fall planting, winter sowing milkweed seeds is also an option.

More Questions or Comments about fall planting milkweed seeds? Please read through the comment section below….

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Hi Tony, I planted a ton of milkweed seeds this past fall all over my 1 acre back yard. A lot of it. I used your technique above (along with several pods which I simply let fly wherever they wanted). But NONE of them have germinated or grown! The only plants are the ones that established themselves last year (3 or so). I am stumped. It’s currently May 21 — is it just too early, or is milkweed really this hard to grow?! Appreciate any thoughts you might have.
Love your site by the way. Thank you for all your teaching!

Hi Barbara, not sure where you’re located? Our Minnesota milkweed is running behind in some areas of our garden, but the rains we just received today should (hopefully) change that. seedlings typically take longer to emerge than returning perennials so hopefully you’ll start to see some progress soon…good luck!

Hello! I live in Michigan, and have a large patch of common milkweed in my
flower/vegetable garden that increases every year. If that area is rototilled lightly,
will it still come back ?
Thanks for all the wonderful information you give, and for inspiring me to raise

Hi Cindy, the taproot and rhizomes can go pretty deep so I wouldn’t expect that to be an issue.

Do I still have to cold stratify my butterfly milkweed seeds if I plant them in fall or winter?

Hi Vanessa, if you plant in fall/winter, they will get a natural cold moist stratification outdoors.

Hi Tony! I want to split my swamp milkweed plants, so I have plenty next summer. When is the best time to do that, fall or spring?
Thank you!

Hi Sue, I prefer doing this in fall when you know where everything is situated in the garden

Hi Tony I just received on(9/29) 50 Ice ballet swamp milkweed seeds that are stratified. I will be starting seedlings indoors this winter. Do I need to keep them in the refrigerator or since they are already stratified can they be kept at room temp until I plant them in 3 or 4 months? I will also plant a few outside in Nov like you said.

Hi Diane, I use refrigerator stratification 1-2 months before planting. It’s always a good idea to try a couple different propagation methods to see which one you have the most success with.

Last week I harvested 50 milkweed pods and dried out the seeds. (Manchester, NH) I’ve located another field with hundreds of milkweed plants that have lost their leaves but pods have not yet opened. But I am having replacement knee surgery Oct 10th so I won’t be planting any seeds this fall. However, Next Spring I will be teaching the children of several local elementary and middle schools how to make campus vegetable and flower gardens. Milkweed will be planted around the perimeter of the gardens . I have a Troybilt rototiller to do the difficult cultivating . the children will help compost the soil with ground maple leaves. I shred leaves and sift the result through 1/4 inch mesh. We then rototill and use hoes to work 8 inches of shredded leaves into the soil. I do that every year in my own garden. The children will also be making bird and butterfly houses to put in these gardens. …………….In reference to the milkweed seeds. Should I refrigerate or freeze my seeds for early Spring planting? Vegetables harvested in the school gardens will be served in the school cafeterias

Hi Francois, I keep our seeds in a cupboard and refrigerator stratify 1-2 months before planting:

I am going to try this in Nov! I am not new to gardening, but I’ve lived in an apartment the last 10+ years with little opportunity to plant anything. This year we bought a house with a big yard, so now I can plant the butterfly garden I’ve been wanting for the past few years! I actually got some milkweed seeds a couple years ago. I don’t know how well they will germinate, being somewhat old, but It won’t hurt to plant them and see what happens! I live near St. Paul, MN.

The milkweed plants are “exploding” their pods right now so it would be a good time to take a walk and collect some fresh ones.

I am new to this. I want to make a butterfly garden and live in northern oklahoma. When is the best time of year to plant butterfly milkweed?

Hi Leisa, I prefer fall planting perennial plants. This gives you a nice head start the following spring. For seeds you could also try winter sowing:

I’d like to plant milkweed (and other native wildflowers) in an area that is currently grass.

Can I just put the seeds right in the ground under the turf, or do I need to pull out or turn over the grass?

I’d like to leave the grass until the flowers get started so I can avoid all the weeds taking seed on the open dirt. At least that seems like a good idea. What do you advise?

Hi Holly, I would remove the grass, turn over the soil in case it’s compacted, and amend with compost if needed…what your proposing sounds like it could end up being more work in the long run if the seedlings/plants don’t thrive.

Thanks for the advice Tony!

I just milkweed seeds I never planted them before, but I’m not new to gardening but I must admit this is LEAVING me a little unnerved. I purchased milkweed that are sapose to be. Monarch butterflies favorite. I hope I did the right thing.

Hi Ellen, if the seeds are prerennial and you have monarchs in your region, fall planting milkweed is a great idea…good luck!

I have raised several dozen Monarchs since I was a child in Pennsylvania. Now I am in Norther Illinois and I have honeybees. It turns out that honeybees love milkweed flowers so I want to combine the two and am hoping to plant several acres of milkweed to help the Monarchs and the bees both. Any ideas on how to plant that many at one time?

Hi Bret, I just added some info about pollinator fields if you look at #7 under Assess Your Situation:

Is it possible to take the milkweed seeds that I have collected and am not going to plant and instead of cold stratifying them in the refrigerator put them in plastic bags outside but inside a plastic storage bench? I want to be able to give these out at my garden club’s plant sale in May to those who come to the sale.

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Hi Donna, if the temps inside are comparable, it should work…good luck!

I live in Lancaster County PA. I had 100 Monarchs this year and had to pay about $300 to buy more milkweed from our 2 local vendors. This year I fall planted 500 Swamp Milkweed seeds(I always have good luck with Swamp Milkweeds). My question is-if I’ve covered seeds with leaves and burlap (and chicken wire)do I need to water them through the winter?
Martha Smiley

Hi Martha, is this so the seeds aren’t dug up? They should still get sufficient moisture through the winter for a cold moist stratification. I wouldn’t worry about watering, Tony

This is the first year I planted milkweed (native to northern Illinois) in my flowerbed. The plants in the fall are now about 18 inches tall, and though they did not bloom or produce seed pods this year, I found that the Monarchs were most likely to lay eggs on these tender new plants for their tiny little caterpillars to start out on. I raised 24 butterflies this year and have gathered lots of seed from other sources for myself and many friends that have become interested in at least helping to provide more habitat for the Monarchs.

Recently bought 2 swamp milkweeds, live in Montana plants are 2ft tall Have been keeping them inside, should they stay inside over winter or transplant outside and cut them back? Nubee in Montana Thanks for reply.

Hi Roy, I would plant them outside now, as they are cold hardy to zone 3.

The pods on both my milkweed and butterfly weed plants are beginning to open so I’ve gently tied them shut in order so the seeds won’t fly away. Is that advisable? Also, once they’ve split open, if I plan to plant them in Nov., in the meantime (between now and then) should I bring the seeds indoors or leave them inside the tied together pods outside? What would you advise?

Sheila in NJ

Hi Sheila, if the seed pods are opening on their own and you can see mature brown seeds, I would harvest them now before the fluff starts coming out.

Couple of questions;

– Does butterfly weed form a single stalk or multiple stalks? I’ve seen pictures where it looks bush like, and didn’t know if this was a single plant or multiple plants close together.

– Are there particular cultivars ( if there is such thing) of orange butterfly weed and if so is there one that stands out?

_ Any recommended online sites to buy seed?

Hi Devin, Asclepias tuberosa (butterfly weed) has many stalks. There is a cultivar that is supposed to grow better in clay, ‘gay butterflies’ which is supposed to be multi-colored…the only difference I’ve noticed is it blooms a little later. There’s also ‘hello yellow’ which has sunny yellow flowers. More Info and Seed resources:

You mentioned butterfly weed has ” many stalks”. What is a ballpark width of a mature plant or does it just continue to spread and get wider?

Hi Devlin, probably about 3 feet. Like many plants, if it has optimal growing conditions and room to grow, it will probably grow larger:

This is my first year to support the Monarch and other butterflies. I purchased the seed from a reputable garden store on line. Had a great crop(, the pods are growing and some have already popped open. I have ruberbanded them, )but will the seeds that have escaped grow again next year. I have harvested seed pods and they are in a paper bag. I had 5 worms this year. I also planted zinnias and parsley next to the milkweed. Attracted at least 6 monachs. We live north of Tulsa, very warm climate. The seeds are planted in raised garden plots due to clay soil. I condition the soil every year. Thanks for such a great and informative website. ?

Can I plant milkweed seeds directly outside in the spring? I’m in zone 4/5 in Ottawa Canada and had saved some seeds from last year.

Hi Maria, yes you can. If they are perennials, plant them as soon as you can get them in the soil. If they’re annual seeds, plant closer to your avg last frost.

Thank you for this helpful post. I planted in small pots that I covered with garden fabric and put in a sheltered spot in my garden in November. The seeds do not seem to be doing anything. When do you see the seedlings emerge? Thank you!

Hi Veronica, it depends on your location, where you planted, and spring spring weather. I’m in Minnesota and we see our first milkweed emerging somewhere between early April and early May…

I just bought the milkweed seed balls. Will those be ok to plant like this?
Or should I have the individual seeds?

Hi Jeri, I prefer planting regular seeds because you can space them out. If you plant seed balls, you’ll have to thin out seedlings or transplant in spring. If you’re going to do that, winter sowing is a better option because the seeds germinate faster in protective containers:

how deep tony? someone said no more than a pencil eraser, but alas i have not had good luck when i plant the seeds.

Hi Kim #4- Put on garden gloves and stick your index finger in the dirt up to your first knuckle. You don’t want to plant too shallow or the seeds could get “relocated” or washed away. good luck!

First knuckle? Technically that’s the largest knuckle.
You’re talking about the one by the fingernail right?

yes Sharon, technically speaking it would be the distal phalanx…

The milkweed I have that is native to my area is asclepias tuberosa. I have been told it is hard to grow from seed and want to try to do it and also share seed with friends. I want to be as successful as possible, so is there anything specific to my variety that I need to do?

Hi Patricia, tuberosa is just one milkweed that is native to your region. You can check the resources age for more natives/perennials or annuals:

Follow the steps on this post for fall planting. you can also winter sow tuberosa seeds. Here’s more info:

This is my first year trying to regrow milkweed. I bought the plant in a garden center and it has shed its fluffy seeds once already. Now new pods are coming out again I have it in a pot and have put it in my garage for the winter.
Can I still plant the seeds in the ground I live in Maryland?
My plant had long green leaves and orange/yellow small flowers it is about 3 1/2 feed tall..

Hi Carol, November is a great time to plant seeds. Before the ground freezes or before your first big snowstorm. good luck!

I have many milkweed plants in my garden which seem to naturally increase each year. This year I have noticed many of the stems have tiny orange aphid-like insects on them. What are my options for getting rid of these insects? I have been cutting the stems down and tossing the insect covered stems in the trash. I wonder if the insects would eventually decimate my milkweed plants. Perhaps this is why milkweeds in my little seaside community are decreasing? I live in coastal CT.

Hi Morgan, here is a post you might find useful in your war against the aphids…good luck!

I had a ton of aphids and used soapy water on them let it dry and washed off with a hose did this two times and they were gone after that..

Hi. I live in MA and have a lot of milkweed seed I was planning on scattering this fall. We are about to have a cold snap 34-28 degrees over the next few days. Seeds have been de-fluffed. Is it still safe to scatter them, or should I wait until the cold snap passes?

Hi Jessica, I would plant closer to November. That way squirrels and other critters are less likely to dig up the seeds…definitely before the ground freezes and before the first big snowstorm. If you wanted to plant now, you could put chicken wire over the area and remove when it gets colder….good luck!

I gathered seeds from our area in Roanoke, VA and I want to try planting them. We have a small hill on the side of my driveway and three milkweed plants grew there. Only one plant got one pod! But I saved the seeds and we found more not far from us. I have no idea what kind they are and never saw any flowers on them. MY QUESTION: our soil is heavy with clay and was previously a pine tree forest. I thought I would scrap up areas on this hills side where the other three grew and see if I can get more to grow next year. I’ve never done this before or even knew to do it! SHOULD I PLANT MID NOVEMBER, late or early November? I’m lost. I’m afraid planting them on the flat at top of hill will have poor results if any due to the soil and lack of good drainage there. Help!

Hi Yvonne, I try to plant before the ground freezes or before the first big snowstorm. It can vary from year to year. You could always try planting in a couple different places to see if one area yields better results…good luck!

One thing that is very important: the seeds and plants need to be in a location that gets a lot of sun.
Also, the seeds do not have to be buried. They are not buried in nature–they just float through the air and land on the ground.

I have sprinkled common milkweed seeds on top of the soil in a large planter, and unknowingly spilled seeds on the ground. They were outside all winter and both resulted in many healthy plants. No birds, squirrels, chipmunks or other critters bothered them.

some milkweed varieties (like swamp and poke) do very well in partial shade. Yes, some milkweed will seed if you just let it fly, but you won’t know where it’s going to end up, and the germination rate will be much lower than if you actually plant it. Also, any area dug up in autumn is prime real estate for critter exploration and digging…glad you have been lucky.

I’m getting some milkweed pods from a friend this week so I can plant some in my yard. Do I have to remove the fluff from the seeds or can I leave it on? I will be sowing the seeds this fall.

Hi Mia, the seeds can get moldy in pods with fluff attached. It’s best to separate them right away, let the seeds dry, then store for the winter or plant:

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Hi Tony, thank you for being so accessible. I live in SW Connecticut and will go get a hand ful of Milkweed seeds from a local sanctuary, I plan to plant them this November with some pre schoolers. I will follow your directions outlined above. So, to prep the seeds, I should separate them from the fluff and then shake the seeds in a bag with some course sand for scarification, right? Then they will be ready for planting,?Should I add anything to the soil? It’s just been lawn up to when I start digging. Should I water as I would a normal garden? Thanks so much, Nina.

Hi Nina, the only treatment native milkweed seeds need is cold moist stratification, which they should get naturally through a cold, snowy northeastern winter. Otherwise they can also be stratified indoors:

You might also want to try winter sowing in containers as a winter school project. We had a lot of success using 2-liter soda bottles doing this last season:

For soil amending, you can always mix in a little compost before planting. You don’t need to worry about watering until the seeds germinate next spring. Good luck!

Thanks for your website. You are so informative. I have never done this but I ordered seeds and plan on planting outside in November since I live in Hugo, MN. I will be so excited to see them pop up in spring. I was going to plant against the garage on east side. Is that OK?

Also, I read other comments and see I might have to transplant the seedlings when they come up in spring…Can’t I leave them where they come up?

Hi Janis, you only have to transplant if your seedlings are competing for space and crowding each other out. You can also just pinch off the seedlings you don’t want, which is easier. You can also plant plants in late summer, early fall for much bigger plants next season. Good luck with your garden!

You might try planting in a couple different area to see where the plants thrive. It sounds like your plants will be getting morning sun and afternoon shade? That typically works for most varieties…

Same technique for planting native plant seeds in containers (which will be left outdoors through the winter)?

Hi Rae, I typically put out winter sowing containers at the end of December or in January. Here’s more info:

When I was young, I saw a story about where all monarch butterflies went to during winter in the ‘states’, which was amazing! Then I heard monarch butterflies could only eat milkweed, then I heard their ‘ranks’ were dwindling…. So I always took care of any milkweeds that ‘appeared in my yard. As well as got the seed pods that appeared later. As far as ‘planting’ goes, I would pull the stalks out by the base, they usually didn’t take up much root, and collected all these ‘fronds of seed-pods and go around all the empty lots around my house and wave them around spreading those ‘parachutes’ willy nilly! Just trying to do my part! I also found that the flowers smelled like ‘lilacs! Who Knew!

I would like to plant milkweed. I’m in Great Falls Montana. Will milkweed grow here? Anymore suggestions..I’m a rookie.
Thank You!

Hi Shelly, yes milkweed will grow in Montana. Check out my milkweed resource page to find milkweeds native to your region, and what milkweed species will be a perennial/annual in your zone.

I live in SoCal, and just got 7 more caterpillars within the last week. I put them in a screened 2′ tall cage with milkweed, and 5 have formed a chrysalis .
What would be nice is hearing about raising Monarchs in other parts of the country, too.

Hello Nancy, thankfully most raising practices are universal. The main differences in warm weather regions are that you have a longer season and some different milkweed options. As I get more of the core site pages/posts finished, I will definitely post more about issues specific to other regions. Congrats on all your new monarchs….enjoy your extended season!

There is lots of milkweed in the wild, but maybe I should plant some in my garden. Where do I buy the seeds?

there are many different species of milkweed you can plant in your garden both native, and non-native. In fall it’s best to sow native milkweed seeds, or at least varieties that can be grown perennially in your region. Here are some options. Click on the orange links to find seeds…htere are seed vendors I purchase from at the bottom of the page. Hope this helps:


Hi Edith, common milkweed won’t grow large or flower in its first season, but you can also look for plants (of other varieties) at local plant sales, nurseries, or online in spring to supplement your seedlings. Tropical milkweed is a non-native that will flower its first season if you start seeds indoors or plant cuttings/plants. These are some of your milkweed options:

going to try to plant some seeds today have lots and lots of seeds, i already put some in the ground the ? i show long does it take once they are in the ground? i heard that the butterflies lay their eggs mostly in november we will see i have about 5 catepillars that i know of right now

Hi Kim, you must be pretty far south for November eggs…in a place with a year-round population? If you plant seeds now, they will be ready to support monarchs until next season. You would need to find plants from a local nursery that doesn’t use pesticides.

i have someone in the neighborhood that sells milkweed and is a habitat if the monarchs, i live in southern california where it never rains, tee hee yet we got 1/2″ yesterday but don’t know when we will get any rain again. most of my plants are filled with the dreaded yellow aphids and the multiply like nothing. can’t get rid of them fast enough.

Aphids are a problem for butterfly gardeners everywhere. Here’s a post that discusses how to stop them from taking over your milkweed….good luck!

thanks have used the finger and hose method. will try anything at this point no pestisides though.

Hi Sharen, if it works it’s not a mistake. By mulch, I was referring to wood mulches that a seed might get lodged under when planting. Putting straw or leaf mulch over the seeds after planting is a great idea.

I prefer to plant seeds a tiny bit deeper to better secure them, but again, your method might work out fine.

Hi Tony,
You mentioned clearing away any mulch & using your knuckle to plant seeds at a good depth. Some of the directions on my seeds said to surface sow barely putting any soil on top of the seeds. I followed those guidelines then sprinkled straw over the area to prevent them from drying out or blowing away. Was that a mistake?

I have used plastic containers to winter sow milkweed seeds with a lot of success. That way in the spring after they sprout I can place them in the gardens exactly where I want them. Just be sure to poke holes in the containers so excess water can drain off. I use any type of container that food comes in, muffins, salad from any fast food restaurant etc. Poke the holes, fill with potting soil (damp) place the lid on tight so the wind won’t blow it off, you can tape it on if you need to or use a rock to hold in place and place outdoors in a wind protected area. The seeds know when to sprout in spring. Hope this helps give an idea of another way to start Milkweed seeds.

Thanks Cindi, we also winter sow seeds. I never like to put all our milkweed seeds in one basket. Here is what we did last season:

Winter Sowing Milkweed Seeds

Tony, I will be planting milkweed seeds for the first time, and have swamp and tropical milkweed seeds. I think the swamp variety needs the cold stratification, and if so, I’m not sure when to plant them. I live in Raleigh, NC (zone 7). Thanks!

Hi Bonnie, November is a great time to plant your swamp seeds…they will get natural cold stratification over the winter.

I am trying something new with a large surplus of milkweed seeds – planting them on top of pots of spring bulbs that will be left in a cold stairwell for about three months, then brought indoors to bloom during the late winter. If it works, the milkweed will have a head start but not require separate handling.

Thanks for sharing this Mary…please let us know how your experiment works out!

I live in Northern Illinois and have some property with areas available for milkweed planting. Bad knees make planting as you illustrate it quite difficult for me. How likely is it that seed bombing in these areas (which vary from dry to semi-swampy and are covered with wild growth) will succeed?
Thank you

Hi Austin, it’s definitely an option if you aren’t able to tend a garden. It might take a little for plants to spread, but after a few seasons of seeding (from the milkweed pods) it could fill out quite nicely. I would try to speak with someone in your region that has actually used milkweed seed bombs before, to see how effective they are. It’s not a method I have used in our garden. However, if you’re not doing anything with the property, it can’t hurt to try. Good luck!

This will be my 1st time planting milkweed as a host for monarchs, swallowtails, etc. I live in Long Beach, NY. All our plants are native plants and the butterflies just love the dwarf butterfly bushes and coneflowers. My question is, since most of our plants are either in large containers or 4 x 2 boxes, can the milkweed be planted in a large container? I was thinking of swamp milkweed and/or tropical milkweed. Thank you!

Hi Robin, both swamp and tropical milkweed grow very well in pots. I grew both types in 10″ pots this season. Tropical will overwinter indoors easily. For swamp, I just dig up extra plants from the garden and pot them in spring.

Hey, I know you! Thanks for that question…I’m looking to plant some this year..

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This is the first year harvesting milkweed seeds for replanting. I plan to make a special Monarch garden in the Spring. The Milkweed I have is just what is native to the area, and are annuals. So my question is would I get better results planting now (in late November) or wait until the Spring?

Hi Tina, if the milkweed is native to your area than it should be a perennial plant. Perennials die back for the winter but the root system survives to produce new plants in spring.

What city, state are you located in? Can you describe what the milkweed looks like when it’s blooming?

Growing milk weed seeds

Milkweeds can be propagated from seeds, cuttings, and, in some cases, from root divisions. This account will deal with storage, treatment and planting of milkweeds seeds and will briefly touch on propagation from cuttings.

Milkweed seeds can be planted in prepared beds outdoors or started indoors in flats. We recommend the latter approach since germination rates are generally higher indoors and it is easier to establish your milkweeds with transplanted seedlings that are well-rooted and therefore more resistant to weather extremes and pests.

Germinating, Growing and Transplanting
Milkweed seedlings can be started indoors in a greenhouse or under artificial lighting and then transplanted outdoors after the average date of last frost. If seeds are started indoors, allow 4-8 weeks growing time before transplanting. Plastic flats can be used to start the seeds. Fill the flats with a soil mix suitable for seedlings (most potting mixes are), thoroughly soak the soil, and let the excess water drain. Sow the seeds by scattering them on the soil surface 1/4-1/2 inch apart, and then cover with about 1/4 inch of additional soil mix. Gently mist the soil surface with water to dampen the additional soil mix that has been added. In an effort to improve germination rates, many gardeners place the seeds in packets made from paper towels and soak them in warm water for 24 hours prior to planting. This method seems to work especially well for seeds of species that require stratification.

After the seeds are sown in the flats, cover each flat with a clear plastic cover or a plastic bag to keep the seeds from drying out while germinating. Then, place the flat under grow lights, in a warm sunny window, or in a greenhouse. Most seeds will germinate in 7-10 days if the flats are maintained at 75˚F. After the seeds have germinated, remove the plastic covering from the flats. Once the seedlings have emerged, the soil should be kept moist by watering the flat from the bottom. You can water from the bottom by placing the flat in a sink or a larger flat filled with 2 inches of water until moisture appears on the soil surface. The soil should be kept moist but some care is needed to keep the seedlings from getting too wet – such conditions contribute to fungal growth that can kill the young seedlings (“damping off”). Thinning (see below) can reduce damping off.

The plants are ready to be transplanted when they are about 3-6 inches in height. Before transplanting, acclimate the plants to outdoor conditions for a few days by placing them in a sheltered location during the day and then bringing them indoors at night. The seedlings should be planted 6-24 inches apart depending on the species (check the back of your seed packets for information). Newly transplanted plants should be watered frequently. Add mulch around the seedlings soon after planting. The mulch holds in the moisture and minimizes the growth of competing weeds. The seedlings should be fertilized 2-3 times during the growing season if using water-soluble fertilizer or once a season if you utilize a granulated time-release formulation.

When small seeds are sown, they are often mixed with sand or fine soil to have better seed distribution. However, this method does not completely prevent crowding of seedlings and thinning will be necessary. Thinning provides more space between plants, increasing the amount of light reaching the plants and the air circulation around them. Seedlings may need to be thinned several times beginning 1-2 weeks after germination. Without proper thinning, you will end up with weaker plants.

When to Plant
Milkweed seeds can be sown outdoors after the danger of frost has passed. Refer to the seed packets for special instructions on sowing the seeds. Keep in mind that seeds have a range of soil temperatures at which they will germinate. Also, remember that under sunny conditions the soil temperatures can be much higher in the daytime than the ambient air temperatures you experience. Plant the seeds early since those planted late in the season may not germinate because of high temperatures. In addition, new seedlings from late plantings can “dry off” before they are even noticed. Asclepias incarnata (swamp milkweed) and A. syriaca (common milkweed) germinate poorly at high temperatures (>85˚F). However, other species such as A. curassavica (tropical milkweed) and Cynanchum laeve (blue vine) germinate well at these temperatures. Germination outdoors depends on soil moisture and temperature and could take several weeks if conditions are not ideal.

Preparation of the Seedbed
If you are gardening for the first time, it is wise to consult with your local county extension agent to see if your soil needs to be enhanced (amended) with soil additives before planting the seeds.

A smooth, clump-free, weeded soil bed will virtually guarantee a successful start for germination and seedling establishment. If vegetation exists in the future habitat location, it can be removed by using a tiller or by hoeing the area. To reduce clumping, do not work the soil when it is wet. The soil should be worked to a fine consistency to ensure good soil to seed contact.

The seedbed should be kept moist until germination. As the seedlings become established, it is important to avoid watering too much or too little. A light watering each day until roots are well established (7-10 days), preferably in the morning, should be sufficient.

Growing Milkweeds from Cuttings
All milkweeds are perennials and some can be grown from cuttings. Cuttings provide a way producing new plants in a relatively short time and it avoids some of the difficulties of starting plants from seeds. To start cuttings, cut the stems underwater, then coat the bottom of the stem with a strong rooting hormone. The stems should be placed in sand, vermiculite, or potting soil that is kept continuously moist. Cuttings can usually be transplanted in 6-10 weeks. Survival is best when cuttings are made from green stems (1/3 inch diameter) obtained from plants fertilized two weeks earlier.

Soil Types
If you have a choice, light soils are better than those with heavy clay. Well-drained soils are generally best but there are some species, e.g. A. incarnata (swamp milkweed) and A. sullivantii, which do well in saturated conditions.

Where to Plant
Most milkweed species evolved in open areas where they were exposed to full sunlight and they will do best if they are planted in the sunniest areas of your gardens. A few species, such as A. purpurascens, appear to require partial shade.

Harvest and Storage of Milkweed Seeds
The timing of the collection of milkweed pods or seeds is critical. Mature pods are those that are within a day or two of opening. If you squeeze the pods and they don’t open easily, they usually do not contain mature brown seeds. Seeds well into the process of browning and hardening will germinate when planted the next season. Pale or white seeds should be not collected. Freshly collected pods dry should be dried in an open area with good air circulation. Once the pods are thoroughly dry, the seeds can be separated from the coma, or silk-like ballooning material, by hand. Separation of seeds can also be accomplished by stripping the seeds and coma from the pods into a paper bag. Shake the contents of the bag vigorously to separate the seeds from the coma and then cut a small hole in a corner of the bottom of the bag and shake out the seeds. Store dried seeds in a cool, dry place protected from mice and insects – a plastic bag (reclosable) or other container in the refrigerator works well.

Seeds of most temperate plants need to be stratified, which is a fancy way of saying that they need cold treatment. To stratify seeds, place them in cold, moist potting soil (sterilized soil is best but is not required) in a dark place for several weeks or months. Since most people prefer not to place potting soil in their refrigerators, an alternative is to place the seeds between moist paper towels in a plastic bag. This procedure works well, in part because there are fewer fungi and bacteria available to attack the seeds. After a stratification period of 3-6 weeks, the seeds can be planted in warm (70˚F), moist soil. Without stratification, the percentage of seeds that germinate is usually low. Seeds from the tropical milkweed, Asclepias curassavica (and other tropical milkweed species) do not require this treatment. “Shocking” seeds that have been refrigerated by soaking them in warm water for 24 hours also seems to improve germination rates.

Heat Shocking
If you have the time, cold treatment is the way to go but if you are short on time, heat shocking the seeds is another (though typically less reliable) method to increase germination rates of milkweed seeds. To heat shock the seeds, soak them in hot (120-130F) tap water for 12 hours, then drain and repeat three (3) times. Place the seeds in a plastic bag wrapped in a warm, damp paper towel for 24 hours.

Even after stratification, seeds of many plant species will not germinate. In these cases, the seed coats appear to require action by physical or chemical agents to break down or abrade the seed coat. “Scarification” with some type of physical abrasion that breaks the seed coat usually works and can be accomplished by placing the seeds in a container with coarse sand and shaking the container for a 30 seconds or so. Scarification may be required for some milkweeds (e.g., A. viridiflora and A. latifolia) and might improve the germination rates of other species.

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