Milkweed Magic

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Butterflies Battle For Their Share

Growing up in New England, milkweed was one of my favorite plants. The smoky purple flowers smelled like vanilla and looked like velvety stars. Monarch butterfly caterpillars ate the leaves and hung their chrysalises on the stout stems. That was all good, but best of all were the lumpy-bumpy seedpods that split open to release zillions of seeds suspended on airy parachutes of enchantingly silky fluff. I loved to use milkweed floss like down to stuff little blankets woven from grasses and plump up pillows made by stitching leaves together. In school, I later learned that milkweed floss had traditionally been used like down wherever it flourished, throughout North America and Mexico.

Even as recently as WWII, school children were urged to gather milkweed floss to fill jackets and blankets and even life vests, since the “silk” has a waxy coating that repels water and insulates quite well if not as well as feather down. Indeed, after decades of mostly benign neglect, milkweeds are coming into vogue as green businesses are once again harnessing the bounty offered by this sturdy family. Today, milkweed floss fills high-end climber’s jackets, fills hypoallergenic quilts and sound baffles, acts as wall insulation, and absorbs spilled crude oil. But what about those butterflies?

Milkweed for Butterflies

Sadly, native milkweeds near croplands continue to be killed by pesticides, significantly reducing the Monarch populations to a fraction of their former splendor. A recent campaign to save them led to a large-scale movement to plant milkweed throughout the country. However, most of what got planted was the tropical species, Asclepias curassavica, a showy plant with vivid red and orange flowers. It’s easy to please in garden settings and Monarchs and other critters can and will eat it happily. In time, the butterflies came to rely on these new plantings and stopped voyaging to Mexico for the winter, since the pickings were becoming just as good in the Southern states. Unfortunately, a persistent parasite (OE, or Ophryocystis elektroscirrha) infects tropical milkweeds, which don’t go dormant in winter. The parasite weakens Monarchs that munch on infected plants and the problem is getting worse as more of the non-native milkweeds are grown.

Right Species, Right Butterfly

Why is it so important to plant the right species? Milkweeds attract plenty of pollinators, from native bees to wasps and insects, which appreciate their pollen and nectar. (European honeybees, however, aren’t adapted to the flower form and may die trying to escape.) Despite the sticky lactic sap, which is toxic in quantity, the foliage supports many moths, beetles and bugs as well as those magnificent Monarchs. So what kind should we plant? Happily, there are several lovely West Coast native milkweeds that will delight Monarchs and host the same range of other fodder seekers too.

Asclepias speciosa, or showy milkweed, is the most common West Coast species and thus an excellent choice to establish in gardens and pollinator meadows. This sturdy plant can reach 4 feet, and often self sows into colonies that will be swarming with Monarchs in season. In midsummer, the pink-to-white, flowers form starry clusters that dangle enticingly above the softly hairy stems and leaves. By autumn, the plump seedpods are frosted with fine hairs, splitting open when ripe to release clouds of silken puffs that carry the flat brown seeds on the wind.

Making Milkweed At Home

In nature, milkweeds are often found in open meadows, along roadsides, in open woodlands, and near streams and ponds. All commercially available milkweeds grow well in ordinary garden soils and a sunny spot. They need some supplemental summer water to get established, but are quite drought tolerant once they get their root system fully developed. West Coast gardeners can grow species from other parts of the country, such as swamp milkweed, Asclepias incarnata, which, not surprisingly, prefers regular moisture and doesn’t mind damp feet at the edge of a stream or bog. Common milkweed also grows mainly east of the Rocky Mountains in a wide range of habitats. A. tuberosa is another East Coaster with orange and yellow flowers that are popular with many pollinators as well as fodder-seeking critters.

Fun as it is to watch butterflies and bees cluster around the blooming plants, it’s vital to remember that milkweeds are the main fodder plant and nursery for Monarchs. If you see caterpillars crawling on the stems and chomping on the leaves, rejoice! DO NOT reach for some bug spray; these plants are born to nurture butterflies by providing juicy greens and a safe home. However, butterflies can be quite creative about selecting a home for their offspring. As you tidy the garden, remember to be both vigilant and gentle. Chrysalises have been found on lawn furniture, hanging baskets, house siding and hose guards as well as on a tremendous range of plants.

Transforming Treasures

As it happens, Monarch butterflies lead complicated lives. Thus, if you find something that looks a bit odd in or around the garden, don’t move it until you can figure out what it is. A Monarch chrysalis is usually green, though it may be light jade or brighter, almost grass green, and as the butterfly gets ready to hatch, you can see more of the wing pattern through the thinning case. When might you find them? Here’s the story: In Mexico, Monarchs hatch out in late winter, migrating into North America in a generally eastern direction. In spring, they lay hundreds of eggs, dotting the undersides of the hairy milkweed leaves with solitary ovoid ivory beads. A few days later, the eggs hatch into little caterpillars.

Elegantly striped in black, white, and yellow, the caterpillars mature in a few weeks. Now they find a safe spot, fasten themselves to a leaf or stem (or pretty much anything), and start shedding their skin from the bottom up. The chrysalis is already formed and hangs for a few weeks (or up to a month, depending on weather). As the inner butterfly matures, the wing colors start to show through the chrysalis. If you’re lucky enough to notice one at that stage, it’s worth hanging around to watch, as the actual emergence is usually quite fast.

But Wait, There’s More!

The warm season butterflies live for just a few weeks, long enough to lay more eggs. The spring cycle repeats twice more before the autumn-born fourth generation appear in September and October. These are the travelers, living for as much as 8 months and voyaging as far as Mexico. This still seems little short of magical to me. Years ago, my family spent summers on Cape Cod in an old artist’s studio. The windows were warping with age, and mine couldn’t quite shut, so a trumpet vine had wiggled its way into my bedroom. There was a chrysalis on one wandering arm and I was blessed and fascinated to watch a Monarch emerge in a matter of seconds from its little case. It flexed its wings, which expanded in the sunlight, then flew off through the open window, sparking a lifelong delight in the natural world.


This entry was posted in Easy Care Perennials, Garden Prep, Pollinators, Sustainable Gardening, Sustainable Living, Winterizing and tagged , , , . Bookmark the permalink.

One Response to Milkweed Magic

  1. Tom says:

    I read with interest your comments about pollenless sunflower. You correctly stated while pollenless, the new sunflowers are still an excellent source of nectar. It might just be that because of their pollenless traits garden sunflowers have become more popular. Hence there is more nectar now available. The millions being grown by professional growers would not be grown at all if they had pollen. So overall I would guess that the popularity created by pollenless sunflower has been a boon to pollinators as planted areas have increased and a lot more insects have gladly taken the sunflower nectar and just sourced pollen from other plants. It’s also a fact that a pollenless sunflower will have pollen on its flowers from many other plant species that insects have visited. The bees can collect that pollen.

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