How to Grow Milkweed

If you want to learn how to grow milkweed seeds, you’ve come to the right place. Read on to learn how best to get your milkweed growing.

milkweed seed pod by HeungSoon from Pixabay

Image of milkweed seed pod by HeungSoon from Pixabay

Much like any other plant native to the Midwest, they go to seed in the fall, are exposed to cold and damp weather during the winter, and then germinate in the spring. However, if you want to start your milkweed in the spring, this is possible as well!

Milkweed plants go to seed in the milkweed pods. These pods will dry out, start to turn brown, and split at a seam that runs vertically. The seeds in the pod will be connected to the tell-tale white floss that helps the seeds to float in the wind and be seeded away from the parent plant.

If you’re collecting seed from a pod, make sure there are no milkweed bugs on the pod because these seeds won’t germinate due to the way the bugs eat. The best time to collect the seed is when the pod has just begun to split at the seam but before the floss has expanded. This will make it easier to clean by hand and the seeds will be matured. Another way to tell if the seeds are mature is the pod will open easily when gently squeezed. If you don’t want to miss when your seeds are mature, put a seed collection bag over the seed pod. A mesh bag will do best so the seeds get some wind to release the seeds when they’re ready.

Once you have the seeds, your planting area is free of weeds. Making sure the milkweed seeds get as much sunlight and rain as possible is important. Planting the seeds directly into the soil could work. According to the Xerces Society, “[d]irect seeding requires good soil preparation” with a smooth seedbed, “lightly packed surface, free of clumped sod and plant debris”.

Another way is to start your seeds in a greenhouse and then transplant the seedlings. To start seeds indoors, allow 4 – 8 weeks before planning to transplant them. This should line up to be after the average date of the last frost. An easy way to help the seeds germinate is to soak a paper towel in warm water, put the seeds on the paper towel, then put them in a plastic baggie. This will keep the seeds warm and encourage them to germinate. There are many other seeds you do this with as well so it’s no different.

According to the Monarch Watch website, the milkweed seeds “will germinate in 7 – 10 days if the flats are maintained at 75 degrees Fahrenheit”. Monarch Watch recommends planting the seeds in flats with a covering to keep the seeds from drying out. They also recommend keeping the seedlings moist but not too wet. Bottom watering would be a good way to do this and prevent fungal growth.

It’s also possible in some places to buy plugs, or already started seedlings, that are able to be transplanted soon after buying.

Once your seedlings are between 3 – 6 inches tall, they are almost ready to transplant. Like most plants that are moved from inside to outside, they need to be acclimated. The best way to do this is by putting them outside in a sheltered area during the day and then bringing them inside at night. This could be done for a few days then they can be planted outside. Plant them 6 – 24 inches apart, it will depend on the species of milkweed and how tall they will get.

Swamp Milkweed by NickyPe from Pixabay

Image of Swamp Milkweed by NickyPe from Pixabay

Germination of milkweed seeds is never a guarantee but trying some of these methods could get the results you’re looking for. Milkweed seedlings can be a bit temperamental but if you’re used to gardening or growing other plants, every plant is a bit temperamental. If it doesn’t work out on your first try, try again and keep trying. Milkweed is an essential plant for increasing the population of butterflies but especially monarch butterflies. To help create that habitat for them is a great way to beautify your landscaping and helping a species flourish.


Use our resources here:

Xerces Society: Native Milkweedsopens PDF file

Monarch Watch: Milkweed Propagation