Meet the Natives: Swamp Milkweed

ESSENTIAL FOR MONARCH BUTTERFLIES, plants in the milkweed family are such important additions to the wildlife garden that I cannot imagine being without mine.

Shown above with a visiting monarch, swamp milkweed (Asclepias incarnata) grows about four feet tall and bears flat heads of pink flowers in summer or even into early fall. A cultivar called "Ice Ballet" has white flowers, while the cultivars "Cinderella" and "Soulmate" are varying shades of pink. The flowers are followed by attractive seed heads in the fall.

As the name implies, this milkweed is a lover of wet places, making it a perfect addition for any wetland (or just plain wet) garden. Mine is growing in a drainage area that also serves to draw water away from my house. The photo below shows the rock-filled drainage ditch leading away from this mini-wetland, which was just scooped out of our clay-filled soil. As you can see from the photo, the flowers attract hordes of butterflies, and not just monarchs. (These are fritillaries.) Swamp milkweed also attracts hummingbirds, hummingbird moths, and certain beetles.


Milkweeds are essential for monarch butterflies because plants in this family are the only ones monarch caterpillars will eat. The milkweeds contain toxic chemicals (warning: toxic to humans though apparently only in large quantities) that cause the caterpillars to taste bad. This protects them from predators.

In Canada, swamp milkweed is native in Manitoba, Quebec, and Nova Scotia; in the United States, it is native to the Northeast; as far south as Georgia, Texas, and Louisiana; and as far west as North Dakota.

Plant swamp milkweed in a moist spot; heavy soil and/or occasional standing water are not a problem. The site should probably receive full sun, though some sources say that this plant can tolerate part shade. Because it has a long taproot, don't plan to move it after you've planted it. Swamp milkweed will spread slowly by rhizomes, and you can naturalize it by scattering the seeds.

The plant is said to attract aphids, but it's highly unlikely that these insects will kill the plant. If aphids gross you out, try to remember that birds take a different view--"bird ice cream," I call them--and will most likely control any aphid outbreak for you. If deer are a problem in your neighborhood, you'll be happy to hear that they don't like the taste of milkweeds.

For more information on milkweeds, I highly recommend the 10,000 Birds blog entry for July 20, 2007. Ten Thousand Birds is a great blog to follow if you're interested in birds, especially if you're a bird watcher.

For additional information on swamp milkweed specifically, check out "This Week at Hilton Pond" for July 15-21, 2001. While you're there, I hope you'll look around this website. The Hilton Pond Center for Piedmont Natural History sure sounds like a place I'd like to visit. The Lady Bird Johnson Wildflower Center also has good information on swamp milkweed.

Vanishing Birds

Photos: Top, populations of the rufous hummingbird have declined 58% since 1967, according to a new study just released by the Audubon Society. Left, populations of evening grosbeaks have declined 78%. Both photos courtesy the U.S. Fish and Wildlife Service, via the Wikipedia.

THE AUDUBON SOCIETY HAS JUST RELEASED an analysis of 40 years of reports on bird populations with the unhappy conclusion that many bird species are in decline: "Since 1967 the average population of the common birds in steepest decline has fallen by 68 percent; some individual species nose-dived as much as 80 percent. All 20 birds on the national Common Birds in Decline list lost at least half their populations in just four decades."

A surprising number of these species would be familiar to most gardeners. Among the popular "backyard birds" that made the list was one of my own favorites, the evening grosbeak. Populations of this large black and yellow bird, which has a distinctive bright yellow slash above its eye, are down an astonishing 78% since 1967. (The decline in this species is second only to the decline in populations of the northern bobwhite, down 82%.) If you live almost anywhere in the United States or southern Canada, you've probably hosted flocks of these birds at your feeders.

Another surprise is the decline in populations of the common grackle, a member of the Corvid (crow) family, that is often seen in urban areas and parks. Because it seems to get along well with humans, I wouldn't have expected this bird to be in decline--but it is, down 61%.

Populations of rufous hummingbirds, which are the hummingbirds most likely to be seen at feeders on the West Coast, are down 58%.

If you live in a rural area or area where there is still natural habitat left, you are likely to spot a lot more good friends on this list: The boreal chickadee (down 73%), eastern meadowlark (72%), field sparrow (68%), and ruffed grouse (54%) are just a few examples from the "top 20" list.

All of these declines can be attributed, one way or another, to loss of habitat. Farmland and meadow birds are suffering because of suburban sprawl, industrial development, and the replacement of old-fashioned farming methods with intensive agriculture. Other birds are in trouble because of climate change, deforestation, and loss of wetlands.

None of these species is on the verge of extinction, at least not yet. But such huge declines are very worrisome. What can we, as wildlife-friendly gardeners, do? Here are Audubon's recommendations, with my comments:

• Protect local habitat. This would include gardening and landscaping in a wildlife-friendly way, as well protecting natural areas where they still exist in your neighborhood. You can also support organizations, such as the Nature Conservancy, that protect critical habitat areas.


• Support sustainable forests. One good way to do this is to buy wood products certified by the Forest Stewardship Council, which is the toughest of the certification programs. The Audubon Society notes that this would be especially helpful to our friends the evening grosbeaks, as they are dependent on boreal forests as breeding grounds.


• Promote sound agricultural policy. Agriculture has a tremendous impact on wildlife, and our shopping and eating choices have a tremendous impact on agriculture. Once you've made your own property wildlife friendly, it seems to me that the natural "next step" is to support farmers who manage their land in a wildlife-friendly way. You can do this by shopping for organic, locally grown, seasonal foods and getting to know your local food producers. Let them know that you care about wildlife-friendly farming practices.


• Protect wetlands. If you have wet areas on your own land, large or small, value them, plant them with native plants, and protect them. They are essential not only for many birds but also for other animals, particularly amphibians.


• Fight global warming. There are lots of ways to do this, but as gardeners we can avoid using tools that are powered by gasoline or electricity, plant trees, landscape in such a way that we reduce heating and cooling costs in the home, improve soil quality, grow our own vegetables ... and probably quite a few other things as well.


• Combat invasive species. This recommendation is particularly relevant to gardeners, as sadly we have been responsible for the introduction of far too many species that have caused degradation of wildlife habitat. The easiest way to avoid planting invasive species and help wildlife at the same time is to garden with native plants.

Each of these recommendations would be helpful not just to birds but to all native wildlife, to say nothing of human health and quality of life! They deserve more discussion than I can give them in a single post. Where they're relevant to gardening and landscaping, I'll be coming back to them in future installments.

Garden Planning vs. Plant Collecting

DO YOU BUY PLANTS WITHOUT KNOWING WHERE YOU'RE GOING TO PUT THEM? If so, welcome to my club: Like me, you're probably more of a plant collector than a garden planner.

Now the odd thing about my being a plant collector is that, when I talk to other people about gardening, I encourage them to be garden planners.

This is the standard advice given to gardeners: Take some time (preferably in the off-season), sit down with a map of your property (preferably to scale), and plan what you want to do where.

This is not only standard advice but also good advice, definitely the way to proceed if you want to use your money and time efficiently and avoid having to undo sudden inspirations that later turn out to have been mistakes. It also helps to ensure that you will have planting sites that are suitable for the plants you want to grow. And perhaps most important of all, this is a more natural approach to gardening. When you plan your garden, you are treating it as a plant community rather than as a collection of individual plants. This is how nature does it, too.

Make no mistake: This is a good thing to do. I encourage it. People have even paid me, on occasion, to create garden plans for them, for precisely this reason.

And yet when it comes to my own garden, I barely plan at all. I have a general idea of where I'm headed (e.g., "front yard = woodland garden"), and I do devote some time to figuring out where to put whatever trees I want to include in my design. But most other planting decisions are driven by what I purchase. And what I purchase is driven by a combination of what's available with the kind of have-to-have-it-right-now craving that is known only to the hardened collector. If you're a collector, you know what I talking about. If you're not, you'll never understand.

If you're a plant collector, you may also do what I end up doing: Namely, I buy plants because I have-to-have-them, even though I don't know where I'm going to put them. I see that Jane is selling a Dodecatheon, for example, and I buy it even though my forlorn front yard isn't ready for this woodland plant yet. The photo above shows Jane's Dodecatheon in a pot on my deck, which is the only spot I could think of for it, along with Jane's Erythronium and one of Jodi's Podophyllums. They'll live there, happily I hope, until my woodland garden is ready for them.

In the meantime, I consider myself lucky to be a native plant enthusiast. Limiting myself to native or "nearly native" plants helps to curb my appetite for plants, much as specializing in Wedgewood humidors might restrain the pottery enthusiast's purchases of expensive breakables.

Being a native plant fan also helps to create the illusion that I am a good garden planner. As long as I stick to natives and nearly-natives, and as long as I do eventually create good sites for them, the plants I'm buying so impulsively probably will be able to form a community. That's because so many of them probably were part of the same, or similar, communities in nature.

Nature can be very kind -- even to her plant collectors.