Weeds for the Win

Come spring, seasoned green thumbs and novice gardeners alike dust off their trowels and prepare to get their hands dirty. Rich soil and green seedlings, sunshine and a soft breeze—these are the things that lure many of us outside.

But did you know you can have fun in the garden while also helping one of the most eye-catching creatures in the country? Monarch butterflies, with their lovely orange-and-black wings, are a delicate harbinger of spring, and yet their numbers are dwindling. Last year, U.S. Fish & Wildlife Service proposed adding them to the endangered species list given that their populations have decreased by as much as 95 percent in the past few decades.

The problem is the loss of milkweed, a flowering plant that once grew abundantly on the margins of farms and woodlands throughout the United States. The rise in herbicide use across the Midwest has all but wiped out milkweed — –the only plant on which monarchs lay their eggs (monarch caterpillars eat nothing else). No milkweed, no eggs. No eggs, no monarchs. Insecticides and climate change are also contributing to monarch declines.

The good news: You can help the monarch population from your own backyard, school, or local community garden. How? Plant some milkweed. It’s a beautiful, hardy perennial, and it’s crucial for struggling populations of monarch butterflies and other pollinators. The nonprofit Monarch Watch has tips on creating “monarch waystations” on private land. In fact, thousands of Americans have registered waystations ranging in size from one hundred square feet to several acres.

To get started, find out what types of milkweed thrive in your area. This map from Monarch Watch divides the country into four eco-regions. At the Milkweed Market shop, you can enter your zip code and see which milkweed species to consider. In the Northeast, common milkweed, swamp milkweed, and butterfly milkweed all do well, while in the West, showy milkweed and antelope horn milkweed are good options.

Here are some simple steps:

1. If you start with seeds, you’ll need to put them in the refrigerator for 30 to 60 days, a process known as cold stratification. Then plant the seeds in peat pots or seed trays in a sunny window before transferring the seedlings to the yard after the last frost. Or you can buy plugs or starts (tiny plants ordered online) or purchase a larger plant from a local nursery.
2. Varieties of milkweed range in color from deep pink to lemon yellow, and most prefer full to partial sun. If you are planting more than one, space the milkweed about 18 inches apart. This gives the tap roots plenty of elbow room. The planting hole should be double the width of the root ball. Now start digging. Milkweed like well-drained soil, so feel free to sprinkle some peat moss and/or compost into the hole.
3. If your root ball is tight, you can “score” it by making vertical slices with a sharp knife or you can simply pull the outer layer of roots free. (The idea is to make it easier for the packed roots to integrate with the soil.) Now gently place the plant in the ground and spread the displaced soil back around your milkweed so that it’s snug. Press the soil around the plant down firmly.
4. Finally, water your milkweed generously. If you chose a variety that is well suited to your region of the country, you shouldn’t have to worry about watering the plant after it gets established. But check the seed packet or nursery pot for water requirements. Milkweed is remarkably low -maintenance in general, which is probably why it’s called a weed! No need to stake, fertilize, mulch, or prune.

In addition to laying their eggs on the leaves of the milkweed plant, monarchs drink nectar from its flowers to help fuel their long migrations, which stretch from Mexico to the northern United States or Canada — –and back. For their return trip to Mexico in the fall, butterflies rely on other nectar sources, so plant some late bloomers in your yard or school garden as well. Asters, goldenrod, coreopsis, and Joe-Pye weed are all good choices.