A couple of weeks ago, Carol Michel, my podcast cohost, told me about a lecture from the Horticultural Research Institute in their tHRIve – WEB SERIES presented by Dr. Daniel Potter, a recently retired urban landscape entomologist from the University of Kentucky.
Now, I’m writing a post about it.
Why? Because some of their research should change how we plant milkweed and which ones we choose to grow.
Here’s a quick recap of what we learned.
Plant more milkweed.
We need 2 billion more stems of milkweed. Urban and suburban gardens are more important than ever as there are fewer places where native milkweed grows in the wild. Everyone needs to plant milkweed in their landscapes and gardens.
Gardeners are the monarch butterflies’ last best hope. I’m not being dramatic here either. They are in serious decline, and we can help them.
Plant milkweed on the edge of the flower bed.
This was a huge surprise to me. I’d always been taught butterflies like messy gardens, but according to their research, Potter and his grad student discovered monarch butterflies visited milkweed plants more when they were planted at the outer edge of a garden bed, with the plants set off by mulch. Monarchs are visual searchers, and mulch helps them see the milkweed plants.
Plant milkweed with a North/South exposure.
Planting areas should have clear views of the milkweed from the north and the south, so monarchs see them as they migrate north in the spring and back south in the fall.
Plant tall milkweed.
Tall milkweed species received more visitors and caterpillars than shorter ones. In their studies, Asclepias incarnata (swamp milkweed), A. syriaca (common milkweed), and A. speciosa (showy milkweed) plants engaged four times as many monarchs as shorter milkweeds.
Note the researchers are from Kentucky. Oklahoma has several tall varieties of native milkweed you can plant in addition to the ones above, like A. viridis, green antelope horn milkweed. I see it in pastures, especially in spring. I planted it in my garden last year. Now, I need to move it to the front of the beds.
Avoid planting tropical milkweed.
In the recent past, I told you tropical milkweed is fine in Oklahoma because it dies completely, but new information from various sources, including the Xerces Society, shows it’s becoming a problem. I grew some this year, but I won’t in the future.
The good news? There is now more of a market for native milkweed now, along with showier cultivars of natives, sometimes called “nativars.”
Tropical milkweed can be bad for many reasons, including flowering longer, which may encourge monarchs to hang around too long missing their chance to overwinter in Mexico.
Monarchs can also become more susceptible to Ophryocystis elektroscirrha, called OE, because very few people, including me, can pronounce it.
Leave monarchs outside.
Unless you’re just trying to show the insects’ lifecycle to students, or you are an educator in some other fashion, experts are asking us to leave monarchs outside. Don’t try to raise monarchs indoors to release later, especially further south. The last generation of monarchs is called the Super Generation or Generation 5, which is larger and stronger than previous generations. Oklahoma and Texas are where that Super Generation is raised. It must be strong as monarchs migrate to their winter home in Mexico, and often indoor-raised monarchs aren’t strong enough.
Indoor raising may also mess up the monarchs’ directional cues from the circadian rhythm.
If you still want to raise monarch caterpillars, here’s how to do it outside.
Don’t just plant milkweed.
Butterflies and other pollinators need nectar plants too. I wrote a post about ten plants to attract hummingbirds, and honestly, many of these plants are also nectar and larval sources for other pollinators too. Attracting butterflies to your backyard isn’t hard. It just takes some planning. Email me about garden coaching if you read this information and feel overwhelmed. I help gardeners plan butterfly gardens all the time. It’s one of my favorite things to do.
Find native plants
Don’t know how to find out which native plants are best for your region? Check out this cool new interactive website from National Wildlife Federation called Garden for Wildlife with a link to Oklahoma’s native plants.
You can also grow many native plants from seed. I’ve used the Okies for Monarchs Central Oklahoma wildflower seed mix from the local Johnston Seed Company in my meadow for the past two years.
You can also buy native plants at various local plant sales. I’ve found native milkweed through High Country Gardens, including the named selection of A. incarnata (swamp milkweed) ‘Soulmate.’ Wherever you buy, ensure the plants are not treated with pesticides, including Bt.
Skip the cute butterfly houses and kill European paper wasps.
Don’t install those little butterfly houses with slits in them. In their studies, Dr. Potter and his graduate students found not only do butterflies not use them as shelter, but they are a haven for European paper wasps, an introduced predator of monarch caterpillars and many other caterpillars. European paper wasps are a voracious urban species and out-compete our native wasps for food. I have never seen one in my rural garden, thank goodness.
In addition to planting milkweed and nectar plants, you might consider making your garden a Monarch Waystation through Monarch Watch. At Journey North, you can also report monarch sightings, including eggs, caterpillars, and adults. Your citizen scientist reporting is a tremendous source of monarch information.
I hope this post was helpful. Some of the information was certainly new to me. Again, email me at email@example.com for a garden coaching session if it’s too much info. I’d love to help.