Growing and Saving the Seeds Of Milkweed
A perennial native wildflower, milkweed is the sole food source of the monarch caterpillar. We offer a range of species within the Asclepias, aka milkweed, family. From Asclepias incarnata to A. speciosa and A. tuberosa, these different species will have mostly similar growing requirements, but it is important to plant the right kind of milkweed for your region. Asclepias tuberosa, also known as butterfly weed or Indian paintbrush, is native to eastern and southwestern North America, and it is a great choice to grow in the Northeast, Southeast, south central and Southwest. Asclepias incarnata, also known as swamp milkweed, is native to the majority of North America except the far western region, making it a great choice to grow in the Southeast, south central, Midwest and Northeast. Asclepias speciosa, also known as showy milkweed, is native to western North America, including the Pacific Northwest, California, the Southwest, and all of the western states.
Milkweed is native to North America. There are a number of species within the milkweed genus, with different species for different ranges across the map. See the "about" section to determine which to plant in your region. This plant family has historically held many uses in Native American medicine traditions. The soft, fluffy seed pods of milkweed were once used as stuffing for pillows and lifejackets.
- Sole host of the monarch butterfly caterpillar, the blooms also feed various useful pollinators
- Pollinator garden, wildflower plantings, native plantings, low-water gardens
Seeds germinate in 14-21 days.
Milkweed seed requires stratification, aka cold treatment, in order to germinate, Baker Creek milkweed seed comes pre-stratified, however, it is best to store your milkweed seed packs in the fridge or a cold location before planting. If you are using this growing guide to germinate hand-harvested seeds from milkweed pods, please follow the stratification steps below.
- Direct sow outdoors as soon as soil can be worked or early spring, alternatively, you can start seeds in trays indoors, 6-8 weeks before last frost date.
- Sow seeds 1/4 inch deep.
- Ideal germination temperature is 65-75 F.
- Be aware that milkweed seeds sprout a long taproot, and if they become potbound, the plants will suffer, so be sure to carefully transplant seedlings to larger pots to give the root systems space to grow. Carefully transplant out after all chance of frost has passed.
Stratification instructions for your own saved seed:
- Milkweed seeds require a cold period in order to germinate. You can direct sow your seeds in the fall or winter. The cold winter exposure will break the seeds' dormancy and they will easily germinate in spring. Alternatively, you can mimic winter's chill in your own home.
- Spread seeds on a moist (but not soaking wet) paper towel, then fold it in half and then half again.
- Place the quartered paper towel into a zip-top plastic bag and press to seal. You want the seeds to stay moist, so the bag must be sealed.
- Store in your fridge for 30-60 days. (30 days is sufficient for A. incarnata, A. tuberosa and A. speciosa.) Remove from fridge about 6 weeks before last frost and start indoors following the above guide.
- Prefers full sun.
- Provide well-drained soil. Swamp milkweed prefers moderately moist soil and can tolerate wet feet or grow in dry land.
- Plant spacing will vary depending on species of milkweed. Ascepias incarnata reaches 3-6 feet tall and can be spaced 2-3 feet apart. Asclepias speciosa reaches 3-6 feet in height and can be spaced 2-3 feet apart. Asclepias tuberosa reaches 1.5-2 feet in height and can be spaced 1-1.5 feet apart.
- Plants are fairly water-thrifty, especially after becoming established.
- Perennial plants may not bloom in first year from planting, however in the first year, non-blooming plants can still host monarch caterpillars and be useful to the monarch population even before blooming.
- A fairly pest-free plant.
- Please never spray milkweed with pesticides, as this plant is very attractive to a number of useful insects!
Saving sunflower seeds is very easy!
- Milkweed pods will be ready for harvest when they can be easily split with a light squeeze of the hand.
- Seeds are mature when they are dark brown in color.
- Gently squeeze pods to open and separate seeds from silks.
- Once seeds have been separated, dry them for about a day in a warm, dry location.
- Store seeds in a cool, dry place; ideally in a sealed bag in the fridge.
- Don't forget that saved seeds will need stratification in order to sprout. You can achieve this by fall/winter sowing seeds or following the stratification guidelines in the seed starting/germination section of this growing guide.