hile modern agriculture and industry are, in large part, responsible for monarch habitat loss, simply having a garden or lawn which is mowed down, tidy, and weed-free, can have an outsized negative impact. To benefit monarch butterflies and other threatened pollinators, we need to allow more weediness and wildness back into the garden.
Working with artist Nancy Blum
, we've created two Art Packs dedicated to the genus Asclepius,
a vital food source for monarch butterflies: Milkweed
) and Butterfly Weed
). This year, we've also added vanilla-scented Swamp Milkweed
to our collection. Each of these varieties can be seamlessly incorporated into a perennial bed or wildflower patch to support monarchs and other butterflies.
Monarch butterflies lay their eggs exclusively on members of the Asclepias genus. These plants serve as the sole source of food for the larvae. The bitterness of milkweed is from the glycosides present in the milky latex, which are the compounds that make monarch butterflies and larvae toxic to predators. (These compounds are toxic to humans too, so please don't munch them or rub the sap into your eyes.)
When someone says "milkweed" most people will picture Common Milkweed (shown above). Common Milkweed
is native to the Eastern US, and is the best milkweed to plant in the eastern states. But orange Butterfly Weed
is also in the Asclepius
genus and shares the same growing instructions.
Members of the Milkweed family are an important nectar and food source for larval and adult monarchs. Butterfly Weed blooms (left) provide nectar after butterflies emerge from the chrysalis. Butterfly Weed is visited by bees and wasps, as well as, milkweed tussock moth and dogbane tiger moth. Common Milkweed is host to many insects, as well, and you will often see red milkweed beetles feeding alongside monarch larvae.
The seeds from the milkweed flower disperse in the fall. Attached to pappi, the silky threads that catch the wind, they disperse from the pods and travel in the wind before landing on the ground. The winter temperatures, snow, and freeze-thaw cycle "plant" the milkweed, and break the seed down enough to allow it to germinate in the spring.
When starting seed from a native plant purposefully, it's always a good idea to mimic how it would germinate in its native habitat. There are 2 methods, each can be done in the the fall or in the spring.
Method 1: Fall-sowing in containers
Pros: By keeping the milkweed contained, the milkweed seedlings are able to grow big and healthy before transplanting. In order to get well established and come back year after year, the plant should grow to about 24" high, allowing it to form a healthy rhizome, which it needs to overwinter. (If the leaves get munched off by caterpillars while still small, the plant won't be able to establish a healthy root system and might not survive the winter.)
Cons: The added time in caring for plants in containers, plus the transplanting time in the early summer.
How to start: Fill 4-6" plastic pots with a well-drained potting mix. Sow 5-10 seeds per pot, spacing them evenly, about 1/4 inch deep. Press in, and water well. Place the pots outdoors, on a porch or at the side of a house is ideal, and leave them there to weather the winter. In the spring, as the temperatures warm, the pots should be moved into full sun to a protected spot and allowed to germinate.
Method 2: In Fall--Direct sowing into a prepared garden plot
Pros: The ease of this method is the most attractive! It is also the most similar to how milkweed is propagated in its natural habitat.
Cons: To execute this method, you will need to plan out the location of your patch in the fall, when most garden chores have ended. The seedlings will also be susceptible to pests and perhaps even hungry caterpillars, which can keep them from establishing themselves to survive over the winter.
Method 3: In Spring--Sowing in containers
This method is almost identical to method 1, except you will need to vernalize the seeds. Eight weeks prior to your last spring frost, start seeds in pots as directed. Water them in well, then, cover with plastic wrap and place in a refrigerator for 2-4 weeks. Then, proceed as above. (You can also start the seeds in cell trays, but this method in larger pots is preferable because the root systems have the room to develop.)
Method 4: In Spring--Direct sowing into prepared garden plot
This method is almost identical to Method 2, except you will sow the seeds in early spring, when night time temperatures are still in the 30s. The seeds can be sown later, though you might see decreased germination as the weather warms.
For more information about which varieties of milkweed are best for your region, consult these regional guides
provided by Xerces.org.