Gary Bachman: Attract Monarch butterflies with milkweed selections

September 12, 2020 7:34:21 PM

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Many of my gardening friends are already on the lookout for the annual migration of Monarch butterflies on their way to their Mexico wintering grounds. Witnessing this migration is awe-inspiring.

 

Last year towards the end of September, clouds of Monarchs made their way through Mississippi.

 

One of the hottest topics in landscaping is planting butterfly gardens to attract Monarch butterflies and provide forage for the caterpillars.

 

 

The various milkweeds (Asclepias spp.) and a few very closely related species are the exclusive forage of Monarch butterfly caterpillars, and these plants are required for their development. Also commonly called butterflyweed, milkweed is low maintenance, attracts a lot of butterflies in addition to Monarchs and is deer resistant.

 

One native that can be found in garden centers is Asclepias tuberosa, a plant that was chosen as a Mississippi Medallion native winner in 2012. This plant has an upright, clumping growth habit with clusters of tubular flowers. These blooms become prominent in late summer and early fall in various shades of orange.

 

This plant produces a deep tap root and doesn't tolerate transplanting to different places in the landscape.

 

There are 15 butterflyweed species native to Mississippi, and seed is available from various online seed companies. They are easy to start from seed in your own in containers until they are ready for transplant.

 

A fun forage plant that Monarch caterpillars love is Asclepias, which is related to Gomphocarpus physocarpus and commonly called balloon plant or hairy balls. This plant produces 2- to 3-inch, lime-green seed pods, and it really creates conversation in the landscape.

 

A species of butterfly weed that isn't native but blooms from spring through the fall is the tropical milkweed Asclepias curassavica. Many garden centers carry this plant, as it grows and flowers in late spring and provides early-season forage for caterpillars before the native species can take over.

 

Especially where tropical milkweed can overwinter, it's recommended to cut plants back to the ground in the fall so the Monarch butterflies will continue their migration to Mexico. This also helps hinder the spread of a protozoan parasite called OE (Ophryocystis elektroscirrha) that can harm the caterpillars.

 

Last year, I started growing a fun new selection of tropical milkweed called Monarch Promise. This is a colorful, variegated plant that is very attractive to both Monarchs and gardeners when grown in the garden.

 

The foliage margins are cream colored and have alternating highlights of red and blushing pink. Full sun certainly enhanced these colors on my plants.

 

The problem I've observed with the various milkweed species is that they are magnets for aphids. While unsightly, aphids don't seem to impact plant growth and flowering. I don't want to recommend the use of any pesticide to remedy the aphid problem, but blasting the plants every couple of days with the garden hose does knock off many of the aphids.

 

There's still plenty of time to plant these butterfly magnets, and many garden centers currently have Asclepias plants you can transplant into your landscape.

 

Gary Bachman is an Extension and research professor of horticulture at the Mississippi State University Coastal Research and Extension Center in Biloxi and hosts Southern Gardening television and radio programs. Contact him at [email protected]