The Homeowners Column

The Homeowners Column

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Planting Milkweeds for Monarchs

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Sandra Mason
State Master Gardener Coordinator
slmason@illinois.edu

Ok, so let me get this straight. You want me to buy a plant with the explicit goal that it will be eaten down to a stub by caterpillars. This act of wanton herbivory goes against everything I was taught about horticulture. In gardening plants are the goal. Right? Well, maybe not. Monarch caterpillars are the perfect gateway bug to the world of habitat gardening. The purposeful act of planting milkweeds in our gardens conveys the courage of our conviction to help monarch butterflies continue.

Luckily many milkweed species exist as good options for our gardens. The name milkweed refers to plants in the genus Asclepias. Milk in milkweed refers to the milky sap exuded if stems or leaves are broken. Monarch butterflies must have milkweed plants to serve as buffet and nursery for their caterpillars. Despite their porky appearance, monarch caterpillars are picky eaters and only feed on milkweed leaves.

A couple caveats in regards to planting areas for milkweeds and monarchs: lots of sun and space. Few milkweeds tolerate shade and large areas help to draw in the monarchs and supply plenty of leaves for caterpillars and flower nectar for butterflies. Chat with your neighbor to plant contiguous areas of milkweeds and butterfly nectar plants such as sedums or asters.

Here in ag country milkweed may conjure up nightmares of an overpowering weed. In open areas common milkweed, Asclepias syriaca, can spread by rhizomes to form large patches. Common milkweed needs disturbed areas so ag fields were once prime territory. In my garden where it has to share space with other perennials it seldom spreads. At 3-5 feet tall the large balls of fragrant pink flowers are perfect in the back of the flower garden.

Prairie milkweed, Asclepias sullivantii, appears similar to common milkweed but is more upright with larger flowers. It is native to moist prairies and river floodplains.

A fabulous milkweed with "knock your socks off" Illini orange flowers in summer is butterfly weed, Asclepias tuberosa. As a perennial native to sandy, rocky areas butterfly weed needs well-drained soil and full sun. At 2 feet tall and wide it is a very usable size in the garden. Butterfly weed is slow to establish and slow to emerge in sprlng so don't give up on it. I wish it would reseed and become a "weed" in my garden. In Sandy's world it's "Monarch Magic".

Swamp milkweed, Asclepias incarnata, is another great garden plant. Monarchs love this milkweed and its rosy pink flowers on 3-4 foot tall stems. Swamp milkweed does best near lakes, ponds or ditches that flood periodically and is fabulous in rain gardens. Swamp milkweed does not like shade, drought or competition. Its claustrophobic nature translates into a need for shoulder room and tends to falter as areas dry out or fill with other plants.

In shadier yards purple milkweed, Asclepias purpurascens, may be a great choice. In its native areas it grows where prairies meet open woodland; therefore, it grows well in moist, partial sun areas. Purple milkweed and swamp milkweed may need watering when plants are young.

Many munching monarch caterpillars appear on my tropical milkweed called bloodflower, Asclepias curassavica. Bloodflower reaches 2-3 feet tall and bears red, orange or yellow flowers. As a tropical it is not winter hardy, but starts easily from seed. Develop your own habitat garden with milkweeds and monarchs. Check out my Habitual Gardener blog for more about milkweeds and habitat gardens.

Join us Monday, September 15, 2014 from 6:30-8:30PM for the film "Plight of the Monarch" and discussion by fine art photographers Kirby and Cindy Pringle at University of Illinois Extension auditorium, 801 N. Country Fair Drive, Champaign. Also hear how The Pringles raise monarch caterpillars and release butterflies. No fees but please register https://web.extension.illinois.edu/registration/?RegistrationID=10804 or PH: 217-333-7672.

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