01 July 2013

Mothering Milkweeds for Monarchs

Asclepias tuberosa, or "butterfly weed," growing in Wisconsin.
In my opinion, native milkweeds (Asclepias) are completely underutilized in the gardens of Texas. We have several species that are just beautiful plants, including Antelope horns, green milkweed, swamp milkweed, butterfly weed, and milkweed vine. Here's a list of milkweeds for Central Texas. Here's another one. And another.

In the Midwest, butterfly weed, Asclepias tuberosa, is actually pretty widely used in garden. It is a prairie milkweed that is native all the way down to Texas. It's bright orange flowers (pictured above) and mounding form are perfect for flower gardens. And though butterfly weed is native to Texas, I rarely see it used here, or even growing anywhere on the roadside.

The one exception I've seen anywhere is actually right around the corner from me, where enterprising neighbors have a small patch of A. tuberosa they planted a few years ago. Here's a photo of one of them:

Antelope horns, Asclepias aperula, is a prime candidate for flower gardens, in terms of form. It requires very low water, has a beautiful mounding habit, gorgeous architectural flowers and very interesting horn-like seedpods that would look great in the winter garden.

Young A. asperula planted in our neighborhood flower garden. I think I got this transplant from the LBJ Wildflower Center years ago.

I've recently been learning why I don't see our native milkweeds in more gardens: they are extremely difficult to grow.

A couple of years ago, I bought some butterfly weed seeds from Native American Seed, and threw them in the ground. A couple actually sprouted and then they quickly died. I'm pretty sure it was snails.

Well, this year, I picked up one of NAM's new "Sustain the Migration" kits with three species of native milkweed seeds and everything you need to try to grow them. It all came in a nice package...

The most important thing to do, they say, is to cold stratify the seeds. This simulates winter, and loosens up the seed husk so the tiny plant embryos and break through and grow.

To cold stratify the seeds, I placed them in small ball jars with some vermiculite (in the package) and water and left them in the fridge for four weeks. (I'm trying to grow rattlesnake master too. It's another beautiful native that seems near impossible to grow.)

After four weeks, I planted the seeds in potting soil and put them outside. Watering them every day, they sprouted and grew to about 3 inches tall over a 4-6 week period.

But now it is put up or shut up time. It's hotter than hell out there, and the worst time to plant anything, but these little suckers had to get in the ground. I planted them today. I will try to baby them through the summer, and hope that the snails, heat, dryness, and whatever else out there doesn't get to them first.

Why all this fuss anyway? Well, as I've said, the milkweeds are beautiful, but they are also extremely important to monarch butterflies, which host exclusively on milkweeds.

And the monarchs, they need our help. As most folks know, monarchs migrate south to Mexico to overwinter in pine forests there. This year the monarch populations had a record low in Mexico (Though they do fluctuate. Check that out here.)
Monarchs migrating to Mexico roosting for the night in West Texas.

It's not clear exactly what is causing the decline in monarchs, as far as I can tell, but it is likely a number of things, from fire ants to climate change. There is a documented decrease in the milkweed. As more land is cleared and more herbicides are applied to roadsides and fields, the milkweed populations go down, and the monarch caterpillars then have fewer plants to grow on.

I've got a little personal mission to get more milkweed around these parts to help these incredible creatures out.

If you don't have the patience for all this milkweed mothering nonsense, but want to support monarchs, plant tropical milkweed. Asclepias curassavica is a native to Mexico that is widely planted around Texas, and it is a great host for butterflies. The monarchs and queens love it. It's a pretty and easy plant to grow, and available in most nurseries. It requires a good amount of water though, from my experience, so just beware of that. Also beware that it's often called "butterfly weed" in the nursery, but it isn't. That's A. tuberosa.

Here are a few links related to all this stuff that have more links for all your learning needs:

Milkweeds of Texas from the Texas Butterfly Ranch
Texas Monarch Watch
Milkweeds of Texas from Mike Quinn

In the meantime, I'm going to mother (or is it father?) my little weeds and hope for some growth and regrowth next spring...


Misti said...

Interesting, I didn't know about the cold stratification. I had collected some antelope horn from a field in Fort Worth and have tried sowing the seeds multiple times...now I know.

In Florida I grew curassavica and it spread readily by seed without me doing anything. It was quite common to grow it and other species around Florida.

Currently I'm growing the yellow version of tuberosa but I'm all about diversifying.

Heather said...

I had A. curassavica in my garden but it didn't survive our winter. My A. speciosa is going like gangbusters. This is a wonderful project and I'm so happy you're spreading the word!

Nancy said...

I love Antelope Horn milkweed. It's one of my favorite flowers. Such a lovely and unusual paler green maroon combination that is just lovely. I wish they would offer more of the milkweeds for gardening. Thanks for sharing!

Heather/xericstyle said...

Excellent info - thank you for sharing milkweed daddy!

Deaton said...

Timely post. I'm trying to grow milkweed and a friend is working on the seeds for us both. Please keep posting about this saga so that we may all learn from this.

Thank you. Deaton

Judi Gustafson said...

I too thank you for your posts. I grow the curassavica as an annual here in southern mountains of NC, but I'm having trouble domesticating the others. I will keep working, though, because I once saw those monarchs hanging in clusters on patches of common milkweed on the BlueRidge Parkway and I fell in love.