Plant milkweed. If you care about the plight of the beloved monarch butterfly, try this simple act of kindness. Plant milkweed. There is no time better than the present to plant milkweed. Are you getting the idea?

Plant milkweed.

There is no subtlety needed here. Most of us know by now that the number of monarch butterflies has greatly declined. There are many reasons for the waning of this stunning species, from habitat destruction to weather, to chemicals and even the loss of, you guessed it, milkweed!

There is something that you can do. Plant milkweed, especially native varieties, to help provide food and a nursery for monarchs.

Monarch caterpillars are very picky eaters and will only dine on milkweed leaves. Female butterflies lay their eggs on the leaves of the milkweed to provide nourishment for the caterpillars that will emerge from their eggs (all 400 of them that one female can lay). As adults, milkweed flowers provide nutritious nectar, with 20 per cent needed sugars to help fuel those fabulous fliers on their long migrations.

On the Vineyard, there are six native varieties of milkweeds — wavy leaf milkweed, tall milkweed, downy swamp milkweed, purple milkweed, common milkweed and orange milkweed, more familiar to most as butterfly weed. And though the Island is naturally rich in this plant, it is declining here and elsewhere due to roadside mowing, habitat loss and alteration, and reduction of field habitat.

All of these milkweed plants are in the genus Asclepias. There are other varieties of nonnative milkweeds that also provide for the monarchs, but there is some scientific debate about whether they should be planted here.

A southern variety, Asclepia curassavica, engenders some concern. Commonly called tropical milkweed, this species can and will survive in our gardens, however, it can host a parasite that will negatively affect the monarchs. It will also stay green over the winter in more southern climes, and there have been studies that show that the monarch will continue to lay eggs on the greenery instead of migrating since there is a caterpillar food source year round. Here on the Island, our winters will knock down the tropical variety, but if it lingers beyond the surrounding foliage, do cut it back.     

The seeds of local milkweeds are coming into their own and can be harvested and planted in the fall. The seedpods are curvy and teardrop-shaped and will burst open to eject their windborne seeds attached to white floss. Some folks that want to harvest the seeds before they are expelled will put rubber bands around the pods to keep the seeds from being ejected. The seeds are ripe and ready when they are brown. Yellow, green or white seeds are not mature. Seeds can be sown in the fall and stratification will happen naturally over the winter.  Then you wait and hope for spring sprouts, as will those monarchs.

And if the saving of a species isn’t enough, consider the multitude of uses milkweeds can claim. Pioneers used the white sap (ergo the name) to cure warts. Native Americans used the floss to insulate their moccasins, and the dried seedpods were employed for decorations. 

More recently, the floss was used to fill life jackets during World War II. It was all the rage in the nationalistic sense to collect and supply this material. In one instance, students from Middleborough collected 109 sacks containing 87,200 pods that made 54 life vests! 

So whether your motivation is patriotic, botanical or just altruistic, I have two words for you.

Plant milkweed.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature.