Garden PSA: “For the Monarch Butterfly, a Long Road Back”

Since we’ve discussed planting milkweed for monarch caterpillars in the Garden Chats, I was slighty perturbed by this article in the NYTimes:

Less than 20 years ago, a billion butterflies from east of the Rocky Mountains reached the oyamel firs, and more than a million western monarchs migrated to the California coast to winter among its firs and eucalypts. Since then, the numbers have dropped by more than 90 percent, hitting a record low in Mexico last year after a three-year tailspin.

Preliminary counts of migrants this fall are encouraging. “But we’re definitely not out of the woods,” said Ms. Satterfield, who studies human effects on migratory behavior. “One good year doesn’t mean we’ve recovered the migration.”

To make matters worse, she and her graduate adviser, Sonia Altizer, a disease ecologist at Georgia, fear that well-meaning efforts by butterfly lovers may be contributing to the monarch’s plight.

In recent years amateur conservationists have sought to replenish drastic declines in milkweed, the only plant female monarchs lay eggs on. But the most widely available milkweed for planting, the scientists say, is an exotic species called tropical milkweed — not the native species with which the butterflies evolved. That may lead to unseasonal breeding, putting monarchs at higher risk of disease and reproductive failure

Butterfly enthusiasts shouldn’t feel bad for planting tropical milkweed, monarch researchers say. But they should cut the plants back in fall and winter. Or even better, replace them with natives. There are native plant societies across the country that can offer advice…

Not all monarch experts worry about tropical milkweed. “Monarchs utilize an immense landscape in the Eastern U.S., and this plant constitutes a tiny, tiny portion of the milkweeds encountered by monarchs returning in the spring,” said Chip Taylor, an ecologist at the University of Kansas who directs the conservation group Monarch Watch. “Should they be there? Probably not. But will they do immense harm? Probably not.”…

More information (and gorgeous pictures) at the link.






10 replies
  1. 1
    tybee says:

    dang. what i’ve been watching the monarchs reproduce on in my garden is the tropical milkweed. and i’ve got lots of it. :(

  2. 2
    I'mNotSureWhoIWantToBeYet says:

    Interesting. I thought some of the weeds growing in a wild part of my backyard were a kind of milkweed, but on looking around now, I see I was wrong. It turns out they’re pokeweed. It seems some birds like the berries, so that’s probably how it spreads, but it’s generally poisonous otherwise…

    Cheers,
    Scott.

  3. 3
    Schlemazel says:

    We have been taking seeds from local milkweed and planting them. At least I assumed they were local . . . crap, now I have to go learn about milkweed species

    But really, if you know the plant is the local of anything it has to be better for the local wildlife than any import.

  4. 4
    max says:

    Since then, the numbers have dropped by more than 90 percent, hitting a record low in Mexico last year after a three-year tailspin.

    Yeah, I used to see Monarchs all the time before the last couple of years but I’m not seeing many butterflies at all.

    In recent years amateur conservationists have sought to replenish drastic declines in milkweed, the only plant female monarchs lay eggs on. But the most widely available milkweed for planting, the scientists say, is an exotic species called tropical milkweed — not the native species with which the butterflies evolved. That may lead to unseasonal breeding, putting monarchs at higher risk of disease and reproductive failure…

    My thinking was that I should plant more of my herbs (which I have) and let the butterflies of all species munch on that. Planting just the milkweed seemed fairly pointless. (Gotta feed the bees too.)

    max
    [‘But I will remember this for future reference.’]

  5. 5
    pat says:

    Monarch butterflies, polar bears, wild rhinos and African elephants…. Only a few of the species that will probably go the way of the Passenger Pigeon in the coming century.

    Glad I won’t be around to see it.

  6. 6
    Another Holocene Human says:

    @I’mNotSureWhoIWantToBeYet: Oh yeah, you see that stuff all up and down the East Coast. Poisonous, but not easily confused with non-poisonous berries at least.

  7. 7
    Another Holocene Human says:

    @Schlemazel: Yeah, when I was a child there was milkweed growing in the wayside. Doubt it was planted by anybody as we lived abutting the woods. Kind of surprised there is such a thing as tropical milkweed. Garden centers (aquarium outlets too) have a lot to answer for.

    Milkweed’s kinda an ugly, unloveable plant except for the monarch caterpillar thing.

    Did see invasive Devil’s Paintbrush every damn where in Upstate New York but on waysides … invasive-yep … ornamental – ayup … rich idiots with gardens – hell to the yep.

  8. 8

    I doubt the Milkweed we have here in North Central PA is of the tropical variety and we’ve been actively cultivating it for a few years now. We save the seeds and have, literally, thousands of seed from their pods.

    I’d be happy share some with you. All I need is your address. send it to dtomkin at hotmail.com

    PS, our yard is a certified Monarch Way Station.

    http://www.ecosystemgardening......ation.html

    We have some great pics at the link in my sig, but I like this animation a lot, it’s a Monarch emerging from it’s Chrysalis
    http://www.cardcreek.com/Birth.....mMr/Medium

  9. 9
    David in NY says:

    But the most widely available milkweed for planting, the scientists say, is an exotic species called tropical milkweed.

    Is this really true? I never heard of it, and I’ve followed this stuff pretty closely.

    @ max:

    My thinking was that I should plant more of my herbs (which I have) and let the butterflies of all species munch on that.

    The butterflies don’t agree with you. They all (or crucially, their larvae) won’t “munch on” your herbs. Many butterflies must lay their eggs on a particular plant (Monarchs, milkweed) because when their larvae hatch, they can only eat that particular plant, not your herbs. They’ve evolved in close connection with that particular plant and the larvae can digest only it. As adult butterflies, they can nectar on many flowers for food. But at the larval stage, if no milkweed, then no food for larvae (even if the adult female would lay eggs on some other plant), and no adult butterflies.

    Finally, the biggest threat to Monarchs may well be declining habitat for their winter homes in Mexico, though I don’t know the extent of that.

  10. 10
    David in NY says:

    I think that “most widely available,” about milkweed seeds, depends on what you mean. The tropical kind isn’t cold hardy and is only a question in the southern coastal areas. If you look around, say, Columbia County, NY, you’ll never see it. And if you want seeds there, all you have to do is find an old field and grab the seeds off milkweed pods growing there. I’ve got a bunch of those seeds in a dried flower floral display I made for Thanksgiving, and next week, I’ll pull them off, plant them in moist seed starting mix in a plastic shoe box, cover them, put them out on my porch, uncover them and let them germinate in late to mid-March. Give them light or sun and water, pot individuals up and fertilize when a few inches high, when bigger put transplant to the ground. They may flower the first year.

    This is not an enormous problem for most of the country. Betty Cracker might be concerned about what kind of milkweed she’s got in her yard, though.

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