Still Here: Milkweed, food fit for monarchs

It’s about time I wrote about milkweed. Its scientific name is Asclepias syriaca, and its common name doesn’t do anything to describe just how important it is. Milkweeds are the only host plants for monarch butterfly larvae. Without milkweed, there are no monarchs. There are many types of milkweed, including swamp milkweed, butterfly milkweed, whorled milkweed, and poke milkweed, but common milkweed is the most prevalent.

If you’ve ever broken or cut any part of the common milkweed, you’ll understand why milk is in its moniker. A highly poisonous sap resembling Elmer’s Glue starts oozing out. This ooze, toxic to humans, is the elixir of life for monarch caterpillars. They munch the leaves and digest the toxins. If a bird or other predator consumes a monarch caterpillar, it would likely be the last one they eat — either because they’ll die or because they will remember the meal that made them violently ill.

If you look closely at a milkweed’s leaves you’ll see other critters lurking, like the aptly named milkweed beetles and milkweed bugs. You may also see earwigs tucked among its thick, broad leaves, or a horde of orange oleander aphids sucking juices from its stem. Multitudes of pollinators are attracted to its tennis ball-sized clusters of pastel pink flowers. A cluster of common milkweed flowers is like a firework frozen in time, but its form and scent are already so charismatic that it doesn’t need flashy colors or patterns. The flowers give way to unripe pods that look like stunted, warped and very anemic unripe avocados. A major difference between the two is that this pod oozes white poison when cut open.

I don’t know what magic the milkweed uses, but by fall, the ooze transforms and the pods, now leathery and brown, open of their own volition, releasing seeds with fluffy white tutu-like floss that help them dance in the wind.

If you see a stand of milkweed with lots of dried pods, grab one or two. You could immediately toss the seeds into the wind and see them take flight and imagine all the places they’ll go before they land. Or you could take the pods with you and find a place where common milkweed is not common. It thrives in sunny places, but as long as the plants have space, they are not picky. They’ll elbow their way through a monoculture of mugwort and through cracks in the sidewalk. They grow in the paved fenced-in no-man’s land behind the astroturf hillocks at the Sunset Park pool, where they seemingly grow straight out of the asphalt. If you don’t think asphalt is great real estate for a plant, keep in mind that the common milkweed and its ancestors could have been growing from that very same spot a thousand years ago. Only the substrate has changed.

In addition to spreading seed, common milkweed also clones itself with its rhizomatous roots. Instead of growing down, these roots run horizontally to the ground’s surface like tentacles, searching for openings — and possibly creating them. When an opening is found, another plant forms and reaches toward the light. The tenacity and prior ubiquity of milkweed is probably where the weed in its name comes from, and its moniker makes it difficult to convey its importance.

Sunset Park is lucky to have other stands of milkweed, but the no-man’s land by the pool is where it’s most protected, largely because this area is fortunately bereft of the kind of park maintenance that ends up destroying it. There are stands near the playground and the swing set, and some that are trying to grow on the grassy lawn behind the retaining wall on Fifth Avenue. Most of these were hacked by mowers last year.

A conversation with one of the mowers illustrated the difficulty of championing a plant with weed anywhere near its name. He allowed me to ramble about the reproductive cycle of monarch butterflies as I tried to convince him to spare a section of the lawn that was dense with milkweed. In the end he told me he had orders to cut it, because it was still a weed.

But this year the milkweed grew back with a vengeance, or with the vigor of a plant that knows it’s needed. If you’re ever by the playground, take a look. The plants are working on their buds, which are green now but should be ready to open in time for the Fourth of July.