Milkweed Propagation
Why Milkweed? Monarch caterpillars feed exclusively on the leaves of milkweed, the only
host plant for this iconic butterfly species. As such, milkweed is critical for the survival of
monarchs. Without it, they cannot complete their life cycle and their populations decline.
Milkweed Loss. Indeed, eradication of milkweed both in agricultural areas as well as in urban and suburban
landscapes is one of the primary reasons that monarchs are in trouble today.
Plant Milkweed. The good news is that planting milkweed is one of the easiest ways
that each of us can make a difference for monarchs. There are several dozen species of this
wildflower native to North America, so no matter where you live, there is at least one milkweed
species naturally found in your area.
Fall is a great time to collect your Milkweed seeds and there are many things you can do with your
harvested seeds. You can save them for next year, give them to friends and family, share with your
community or donate them to your favorite Monarch conservation organization!
You can collect Milkweed pods from your own garden, on private lands (with permission), public
right-of-ways and road sides.
The rule of thumb for harvesting wild plants is to leave at least 2/3rds of the plant to ensure that
the wild population will continue to thrive.
The perfect time to harvest the pods is when they are just starting to pop at the sutures and the seeds
are brown. If the pod is brown and has already popped open releasing their silky fluff, also called 'coma',
you know that they are ready and you can harvest them and remove the fluff later.
If you want to avoid the fluff and be able to take the seeds off neatly and easily, here is a little trick. Look
for green seed pods and the first thing I do is squeeze the seed pod. If I hear a gentle pop and see that
the pod has split at the suture, then I look inside. If the seeds are a nice toffee brown then I know they are
mature and I can collect the pod. However, If the seeds are white or tan, I don’t collect them and let them
continue to mature on the plant.
Milkweed seeds can mold easily so use a breathable paper bag or cardboard box when you are out
collecting.
This is a fun and relaxing activity. Let them sit for about 2 weeks so they are dry and easy to remove.
Squeeze the pod until it pops open at the suture and grab the narrow end of the pod. Gently pull until
the seed follicle comes out of the pod. Rake your finger nail along the seed follicle, going WITH the
grain of the seeds. They should pop right out!
After you remove the seeds, you’ll want to let them dry out for 3 days to a week. Let them dry on cardboard
in a well-ventilated area. A porch, mudroom, barn, or shed works well for this. If you are harvesting in the
Spring, you can most likely skip this part unless it is after a rain.
Once they have dried out, store them in small manila envelopes and date them. Do not store them in
plastic bags because this will often cause them to mold since it is not a breathable material.
After you have dried your seeds, you can place them in a cold, dry place for the winter so they can go
through a cold stratification period. This will increase their germination rates. Another option is to sow
them in the ground in the late fall so they naturally go through a stratification period.
All milkweeds are perennials and some can be grown from cuttings. Summer is a prime time to
take native milkweed cuttings for a few compelling reasons:
Native milkweed plants still have herbaceous, viable stems
Mid-summer cuttings will grow roots in plenty of time for fall planting
You can keep the cuttings containers outdoors
Cuttings provide a way producing new plants in a relatively short time and it avoids some of
the; difficulties of starting plants from seeds. Cuttings can usually be transplanted in 6-10 weeks.
Survival is best when cuttings are made from green stems (⅓- inch diameter) obtained from
plants fertilized two weeks earlier.
Use organic peat or all-purpose potting soil in pots. An alternative idea is to place
cuttings in 2 liter soda bottles to give each cutting optimal growing conditions in their
own mini-greenhouse.
Mix in perlite or coarse sand to allow more air to reach the newly forming roots.
Water soil thoroughly.
Insert chopstick/pencil in soil to make holes for placing cuttings.
Use a sharp hand pruner to take cuttings and cut the stems under water.
Take a cutting that has between 3-5 leaf nodes (or is about 4″ long).
Pinch off all but the top two pairs of leaves from your cuttings so that water doesn’t
evaporate through the leaves.
Scrape the bottom third of the cutting with a sharp knife.
Coat the bottom of the stem with a strong rooting hormone.
Place cuttings in holes and secure soil around them.
Keep cuttings in an area that receives light, but minimal direct sunlight.
Spray soil and leaves daily.
Plant native milkweed cuttings in an 80/20 mix of perlite to peat moss, which is a more
traditional mix for starting stem cuttings than starting them in soil. Adding sand and/or
vermiculite to the mix could also increase your success rate for milkweed cuttings.
Alternatively, you could direct planting your cuttings in regular garden soil using rooting
hormone powder.
Butterflyweed, Asclepias tuberosa
Common Milkweed, Asclepias syriaca
Showy Milkweed, Asclepias speciosa
Sullivants Milkweed, Asclepias sullivantii
Swamp Milkweed, Asclepias incarnata
Whorled Milkweed, Asclepias verticillata