Native Maine Milkweeds to Grow for Monarchs and More

Native milkweeds are host plants for monarch caterpillars, but other pollinators love them too! Some gardeners dismiss milkweed plants as weeds and never consider intentionally growing milkweed as an ornamental. But milkweeds have a lot to offer, including an adaptable nature, low maintenance needs, and colorful, summer-blooming flowers. And, of course, milkweeds are the plants to grow if you want to see more monarch butterflies!

In North America, there are about 100 native species of milkweed, but here in Maine, we have just four. This guide will help you pick the best type of native milkweed for your Maine garden and provide you with planting and care tips so you can attract more monarchs with these classic native plants!

Milkweed and Monarchs

Adult monarch butterflies drink nectar from an assortment of native plants and wildflowers; however, monarchs are completely dependent on milkweed for reproduction. While some butterflies use different plants as hosts for their young, monarchs only lay their eggs on milkweed and developing monarch caterpillars only eat milkweed before they develop their wings!

Unfortunately, due to climate change and other factors, milkweed is becoming increasingly scarce in some areas, which directly affects monarchs, as well as other pollinators. Deliberately planting native milkweed is one of the best ways to help monarch butterflies make a comeback. But you can also help monarchs by avoiding pesticides and planting other nectar-filled flowers for adult butterflies!

Native Milkweeds to Grow in Maine

While most types of milkweed thrive in full sun, some milkweeds can also tolerate partial shade and waterlogged soil. When selecting milkweed varieties for your garden, consider how much light and water your flower beds receive, and think about how much space you’d like to dedicate to growing milkweed. You may find that your garden is best suited for a specific type of milkweed, or you may want to grow several types of milkweed at once for more variety!

Common Milkweed (Asclepias syriaca)

If you spot milkweed growing wild in meadows and along road verges, chances are you’ve found common milkweed! This highly adaptable milkweed grows best in full sun and dry soil and it produces tons of globe-shaped, pinkish-purple flower clusters in summer, which pollinators can’t resist. Compared to other milkweeds, common milkweed can grow aggressively, so you may want to keep it in pots or raised beds, or plant it in a wild section of your yard where its roaming rhizomes can spread out.

Swamp Milkweed (Asclepias incarnata)

Most milkweeds prefer well-draining soil, but swamp milkweed loves having wet feet! A prime candidate for rain gardens and other soggy spots, swamp milkweed doesn’t grow as wildly as common milkweed; it stays in a neat clump but plants can get a bit taller. When mature, you can expect swamp milkweed plants to grow about 3–4 feet tall, but it can stretch up to 5 feet high in shady conditions and produce purplish flowers that last from summer to early fall.

Butterfly Weed (Asclepias tuberosa)

Pink and purple flowers have their charms, but if you want to get even more color from your milkweed plants, try growing butterfly weed! This pint-sized milkweed only grows to about 2 feet high, but its bright orange blooms make a big impact in flower gardens. A top choice for container growing, butterfly weed can also be kept in larger beds as long as the soil is well draining and the plants get lots of light.

Poke Milkweed (Asclepias exaltata)

While poke milkweed’s pale, pinkish-purple flowers have a more subtle look than common milkweed, this delicate beauty looks becoming in native plant gardens and wildflower meadows. Wild poke milkweed plants typically grow in clusters along forest margins and roadways, and they bloom earlier in the season than other types of milkweed. Grow poke milkweed on its own, or pair it with common milkweed and butterfly weed—they have similar care needs!

Dogbanes (Apocynum cannabinum and Apocynum androsaemifolium)

Although dogbanes aren’t exactly milkweeds, milkweeds and dogbanes are closely related plants that have a similar look and feel and can be used in much the same way in landscape designs. Maine has two common types of native dogbane—Indian hemp and spreading dogbane—both of which can be grown as low maintenance, flowering plants in wild areas of your property to attract wildlife. Just keep in mind that while pollinators love dogbanes, these plants are quite toxic, especially to dogs and livestock!

Milkweed Companion Plants

If you want to attract more monarch butterflies, growing native milkweeds is a good place to start. But don’t forget to also plant some summer- and fall-blooming native plants to supply adult monarchs with food before they migrate south. These native plants can all be grown near milkweeds, and monarchs love them too!

7 Milkweed Growing Tips

Whether you grow swamp milkweed, butterfly weed, or another native milkweed variety, milkweed plants aren’t hard to keep as long as you provide them with the right balance of light, moisture, and care. Use these tips to keep your milkweed looking its best and make your plants even more appealing to pollinators!

Sow milkweed in groups. Known as “cluster” or “drift” planting, sowing ornamentals in groups of 3 or more gives planting arrangements a more natural look and makes it easier for pollinators to feed!
Grow milkweed in full sun. Although some milkweed plants can tolerate partial shade, most milkweeds flower best when they receive at least 6 hours of direct sun daily.
Keep milkweed in a sheltered spot. Butterflies will have an easier time feeding if you grow milkweed in an area where plants are protected from strong winds. While you’re at it, make sure to plant milkweed far away from bird feeders to shield monarch caterpillars from hungry songbirds!
Steer clear of pesticides. Pesticides can harm pollinators as well as pests, so don’t apply them near milkweed. If orange milkweed aphids invade your milkweed plants, don’t worry. These pests don’t do much damage to milkweed, and treatment isn’t needed.
Experiment with cold stratification. Milkweed and dogbane seeds germinate best when they are cold stratified. This can be accomplished by planting seeds outdoors in fall or stratifying seeds in your fridge for a few weeks prior to spring planting. If you forget to cold stratify, you will still get some germination when sown indoors in the spring with your vegetable seeds.
Wait for seed pods to open. If you collect your own milkweed seeds, only collect seeds when the seed pods are easy to open. It’s okay to collect seeds from green pods if the pods split open when you press on them with your fingers!
Plant plenty! According to the University of Minnesota, one milkweed plant will support one monarch caterpillar from egg to metamorphosis!