Milkweed is an important food source for monarch and other caterpillars. It comes in many varieties and can be grown nearly everywhere. In this short International Butterfly Breeders Association post by Bonnie McInturf, we show you how to collect milkweed seeds. How to Plant Butterfly Weed Seeds. Sometimes called pleurisy root, butterfly weed (Asclepias tuberosa) is a perennial wildflower grown for its showy, reddish-orange flower clusters and textured, lanceolate leaves. It thrives throughout U.S. Department of Agriculture plant hardiness zones 4 to 10, where it is … How do I germinate butterfly weed seeds? Harvest the seed pods of butterfly weed when the pods begin to split. Seeds can be sown directly outdoors in late fall or started indoors. When sowing
A Simple Method for Collecting Milkweed Seeds
There are many reasons to collect and grow seeds from your garden, especially milkweed seeds.
Maybe you have a milkweed plant that you or a neighbor really liked last season, and you want to continue growing it next year. Sometimes there is local variation within a plant variety, and this plant is especially well-adapted to your area, as evidenced by last year’s success. It is worthwhile trying to get seeds or starts from the area in which you will be growing it.
Get an Earlier Start
Nurseries plan for demand, and depending on where you live, they might not offer milkweed plants as early in the season as you would like. Sometimes you can get a head start on the butterfly season by using a sheltered area such as a porch or balcony, and growing your own milkweed will allow you to get set up earlier.
More Milkweed Varieties
Usually the more popular types of milkweed seedlings are offered by nurseries or online, but a much wider range of options is available when you start your own from seeds. Since the concentrations of cardenolides vary between species of milkweed, it is always good to have a range of options in your garden.
Avoid Pests from Nurseries
So, don’t let this one alarm you! As conscientious as nurseries are, there is always the chance of soil-born diseases coming into your garden, and commercial growers sometimes have outbreaks of mealybugs, etc. The more you can grow yourself, the better.
If your plants from last year have rewarded your efforts with large numbers of seeds, you now have a free source you can use yourself and share with friends.
Teach Kids about Plant Life Cycles
Starting seeds is fun and addictive – it’s a great way to get kids involved and let them learn about nature.
When to Collect the Pods
Here is a collection method that requires no special equipment and is quick and easy. Grab your safety glasses* and let’s get started!
Pods can be collected at various times throughout the year, either before or after winter. In the fall is best, as the pods will not have split open as much, allowing moisture to get in. The problem with moisture is that mold can form. When collecting in the fall, it is handy to get the pods before they actually pop open too much, releasing seeds attached to parachutes of fibrous floss (called coma). That can make a mess.
Secure Pods Before They Pop Open
If you have access to the pods while they are ripening, secure them with paper strips sometime in the summer before they pop open. Cut up strips of heavy brown paper (from paper bags or heavy craft paper) and secure the strips around the pods with masking tape. Some people use rubber bands for this, but those often break down in heat and sun. You know those old rubber bands you find in the back of the drawer that are sticky?
Collect seeds before pods look like this.
IBBA (Asclepias curassavica) Milkweed Seed
How to Tell When Pods are Mature
When you have taped up all the pods, keep an eye on them and look for when they start to turn brown. There are several things you can check on to make sure the seeds are mature:
- The seed pod has started to turn slightly yellow
- The seed pod has begun to split open or will split along a seam with a gentle squeeze
- The seeds inside have turned a relatively dark color, not white or cream colored
Never pick pods that are completely green. If a pod cracks open with a gentle squeeze and it’s slightly yellow, it’s ready!
Removing the Seeds
Go ahead and pick the pods and get them to a table with a clean bowl and a paper bag. Many people do this outdoors in case the floss starts floating around.
- Take a pod in your hands, holding the stem side in one hand and the end in another. Strip off the covering of the pod so that you have a cone-shaped arrangement of seeds attached to the floss.
- Holding the end of the pod that is mostly floss with one hand, pull the seeds off with the other, putting them in the bowl as you go.
- Place the seeds in a paper bag to continue drying and label it with the date collected and type of seeds.
Don’t forget to wash your hands before taking off your glasses, and you’re done! Time to start preparing for the next season!
IBBA Tropical Milk Weed Seed
Before Planting Your Seeds
Unless your seeds are tropical milkweed (Asclepias curassavica) place them between layers of damp paper towels in plastic bags or closed containers in the refrigerator for 30 days before planting.
This simulates the cold and moisture that they would experience in nature to help break down the outer layer of the seed casings to allow germination. This process is called cold stratification. Many species of milkweed require cold stratification, but tropical milkweed seeds do not.
IBBA Monarch on Plant
Thanks to Darlene Loo-McDowell of Sharing the Butterfly Experience and Connie Hodsdon of Flutterby Gardens for providing information used in this post!
Milkweed Sap Warning
*Milkweed sap is an eye and skin irritant. Many people get sap on their hands and then rub their eyes. Milkweed sap in the eyes is a medical emergency, and who has time for a trip to the emergency room? Tip: If you don’t want to wear gloves, at least wear safety glasses. It would be difficult to rub your eyes with glasses in the way, so the safety glasses being on your face will be a reminder that you still need to wash your hands.
Wow! Very informative and neatly presented. I have not seen another article like this anywhere. I didn’t know about the cold stratification for natives or the sap issue. Maybe that explains why some of my seeds did not sprout. Thanks
Thanks, Russ! Now I’m experimenting with propagation from cuttings. There is so much to learn! What type of seeds were you trying to sprout?
How to Plant Butterfly Weed Seeds
Sometimes called pleurisy root, butterfly weed (Asclepias tuberosa) is a perennial wildflower grown for its showy, reddish-orange flower clusters and textured, lanceolate leaves. A member of the milkweed family, it thrives throughout U.S. Department of Agriculture plant hardiness zones 3 to 9, where it is frequently added to butterfly gardens and native plant landscaping.
Butterfly weed and milkweed seed pods may be harvested and planted to support Monarch butterfly caterpillars. Butterfly weed grows well from seeds, which must be harvested in late summer and either sown immediately in the garden, or started in spring after a lengthy chilling process. The seeds are viable and will germinate with little care, although they must be planted at the appropriate depth to ensure successful sprouting.
Gather the butterfly weed seeds in late summer or autumn, once the pods dry to a light, rosy-beige color, but before they split open. Put on rubber gloves before handling the pods to protect your hands from the mildly toxic sap.
Before you begin to harvest the butterfly weed pods, sterilize your cutting tools. Dip the blades into a full-strength household cleanser, such as Lysol or Pine-Sol. Repeat between cuts to prevent the spread of diseases.
Snip off the pod using pruning shears. Slice lengthwise along the edge using a utility knife. Pry open the seed pods. Scoop out the seeds and fluffy matter inside and place it in a bucket.
Leave the bucket outdoors for two or three days to let the fluff blow away. Stir the seeds occasionally to loosen more fluff. Do not worry if some of the fluff remains, since it won’t inhibit the germination process.
Place the butterfly weed seeds in a plastic bag filled with 1 cup of moistened perlite. Store the bag inside the refrigerator for three months. Mist the perlite with water every few days to keep it from drying out completely.
Prepare peat or other biodegradable pots before removing the butterfly weed seeds from the refrigerator. Fill 3-inch starter pots with a mixture of half seed-starting compost and half coarse sand. Moisten the mix and press it firm.
Make a 1/4-inch-deep planting hole in the center of compost mixture. Drop one butterfly weed seed in the planting hole. Cover it with a loose layer of compost. Mist the compost to settle it.
Arrange the starter pots on a propagation mat near a source of bright, indirect light such as near a partly shaded south-facing window. Set the temperature on the propagation mat to 86 F during the day. Turn it off at night.
Water the butterfly weed seeds whenever the compost feels barely damp when pressed. Apply the water by the spoonful or use a spray bottle to keep from dislodging the seeds.
Watch for germination in two to three weeks. Turn off the propagation mat one week after the seeds sprout. Move the pots into a cold frame outdoors or against a south-facing wall with noonday shade.
Transplant the butterfly weed into a permanent bed in spring just after the last frost. If planting butterfly weed in clay soil, dig in 2 to 4 inches of compost to lighten the soil, or consider building raised beds to increase drainage.
Spread a 1-inch-thick layer of mulch around each plant. Water weekly to a 2-inch depth during their first summer, then cease supplemental irrigation.
How do I germinate butterfly weed seeds?
Harvest the seed pods of butterfly weed when the pods begin to split. Seeds can be sown directly outdoors in late fall or started indoors.
When sowing seeds outdoors, work up the soil in a protected location in early to mid-November. Scatter the seeds over the prepared seed bed and then cover the seeds with approximately 1/4 inch of soil. The cold, moist conditions over winter improve seed germination. Seedlings should emerge in spring. Carefully transplant the seedlings to their permanent locations when the seedlings are 3 to 4 inches tall.
To start seeds indoors, fill a flat with a commercial germination medium (such as Jiffy Mix). Moisten the medium. Scatter the seeds over the surface of the germination medium and lightly press the seeds into the material. Cover the seeds with an additional 1/4 inch of the germination mix. Carefully moisten the additional material. Slide the flat in a plastic bag and place the bagged flat in the refrigerator. Leave the flat in the refrigerator for 4 to 6 weeks. After 4 to 6 weeks, remove the flat from the refrigerator and place it in an area with a temperature of 70 to 75 degrees Fahrenheit. Seeds should begin to germinate in 3 to 4 weeks. (If no seedlings appear after 4 weeks, place the flat back in the refrigerator for another 4 to 6 weeks and repeat the process.) Take the flat out of the plastic bag as soon as seedlings appear and place the flat under fluorescent lights in a 60 to 65 degree Fahrenheit location. Transplant the seedlings into individual pots when the seedlings are 1 to 2 inches tall. Continue to grow the seedlings indoors under fluorescent lights for several more weeks. Prior to planting outdoors, place the seedlings outdoors in a shady, protected location and then gradually expose the seedlings to longer periods of direct sun. Plant the seedlings in their permanent locations after they have hardened outdoors for 10 to 14 days.