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The Monday Garden
Great Americans: The Monarch's Milkweed

Issue No. 167 - June 5, 2005
by Sue Sweeney

How about contributing to the monarch butterfly survival fund? Itís easy: plant a milkweed today.

To grow our native milkweeds, you need at least half-day sun. Also, many varieties prefer their roots a bit damp. What's in it for you? Dramatic flowers, interesting foliage, great seedpods, and nectar-seeking butterflies. If you're really lucky, you'll also be delighted by holes in the leaves and ragged edges, the sure-fire sign of baby monarchs. Look for fat caterpillars resembling tiny, horned tigers.

Picture: Common milkweed in part-shade in my motherís garden. The first plant probably came from a wind-borne seed but in the garden, it spreads by underground runners. I half-heartedly tried to pull it up once or twice but it wanted to stay, so Iíve been leaving it alone. No bugs yet but perhaps weíll get lucky this year. Design-wise, I think the height, shape, and foliage make it a useful contrast plant.
The curious thing about milkweed is not that monarchs are crazy about it and won't eat anything else; it's that practically no one else can stand it. So, if someone's munching on your milkweed, you can be pretty certain that you've hit the monarch jackpot. HOwever, according to The Monday Garden reader, and awesome prairie planter and photographer, M.J. Hatfield, you might also get milkweed tussock moth larvae and milkweed bugs, (pop-up pictures courtesy of MJ Hatfield) which strangely enough have also adopted a striking orange and black color scheme Ė may be the food does it?

Other animals, regardless of species, think milkweed tastes awful and get sick from eating it. It is life threatening in large quantities but tastes so bad that you have to be starving to eat that much of it. Native Americans did eat the young asparagus-like shoots but had to boil them twice to get out the bad juices. Technically, the bad juices are said to be cardiac-active steroids (whatever they are). In many parts of the Americas, milkweeds are (very carefully) used for medicinal purposes.


Pictures: common milkweed flower, green seed pod and opened seed pod.
Downtown Stamford CT and the Mill River at Scalzi Park 2004.

Monarchs, as you've probably read, also taste bad. In fact, so bad that once a bird has tried one, it will shun the species for life. And as you've probably also read, viceroy butterflies look like monarchs to fool birds into thinking that they taste bad too. Viceroys, though, get the best of both worlds: defense against birds and something tastier to eat. The monarchs, of course, get the bad taste by storing the yukky cardiac-active steroids in their bodies.

It is said that there are about 200 native milkweeds, about 100 of them from North America, and countless garden hybrids. Most milkweed nectar will attract humming birds as well as butterflies. Around where I live, we have several native varieties. The most common three are the North American "common" milkweed (Asclepias syriaca), the orange butterfly weed (Asclepias tuberose) which is often seen as a gardenerís hybrid, and the swamp milkweed (Asclepias incarnate). We also have two nasty invader milkweed vines: pale swallowwort (Cynanchum rossicum a/k/a Vincetoxicum rossicum) and black swallowwort (Cynanchum louiseae a/k/a Cynanchum nigrum, Vincetoxicum nigrum).


Pictures: left: orange milkweed (Bartlett Arboretum 2004); right: pale swallowwort, downtown Stamford, 2004.


Pictures: swamp milkweed about to bloom and in fall (Bartlett Arboretum 2004).

If you want to foster baby monarchs (a very good thing, indeed), note that monarchs only like some milkweeds. Web sites on butterflies tend to recommend the common milkweed and the swamp milkweed, both perennial North American natives. If you really want to roll out the red carpet, monarchs' all-time favorites are reported to be certain tropical milkweed hybrids which youíd have to grow as annuals.
Picture: Common milkweed pod, bursting with seeds. The Mill River at Scalzi Park Fall 2004
The fluffy milkweed seeds are good for stuffing things like pillows and floatation devices. The seedpods, which are silky inside like seashells, look wonderful in the garden and in dried arrangements. The milkweed stems contain fiber which can be used like hemp or flax.
Picture: young common milkweed plants in Hoyt Street Alley, May 2005
Picture: Common milkweed spring shoots. The Mill River at Scalzi Park Spring 2004
Picture: Common milkweed in late summer (same scene as above) The Mill River at Scalzi Park July 2003
Picture: same as above, mid-summer 2004
From The Monday Garden. Copyright © by Sue Sweeney. Reproduced with permission. 

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