1. Choose Milkweed Native to Your Region

There are dozens of milkweed species that are native to various regions of North America. “You are seldom more than 50 miles away from a naturally occurring milkweed in the United States,” says Bradfor Grimm from "Grow Milkweed Plants." "Find out what has grown in your region for hundreds of years and grow more of them. The advantage of growing your region’s local milkweed is its incredible ability to grow well with your soil’s makeup, sunlight hours, and annual precipitation.”

The Xerces Society recommends planting milkweed that evolved in your area because they support other levels of the ecosystem, from soil organisms to insects and birds.2 Also, planting introduced species can actually disrupt the monarch’s traditional feeding cycle and contribute to pests and disease.

“By choosing native milkweeds, you’re not just planting a garden—you’re restoring a piece of your local ecosystem,” says Grimm. “It’s a small act that makes a big difference for pollinators and monarchs.” For example, by planting milkweed, you’re also nurturing the milkweed tussock moth and milkweed beetle, whose larvae feed on its leaves like monarchs, and pollinators, including other butterflies, birds, and bees that feed on the flower's nectar.

The National Wildlife Federation recommends the following three species that will work in most regions of the U.S.: Common milkweed (Asclepias syriaca), swamp milkweed (Asclepias incarnata), and butterfly weed (Asclepias tuberosa).

2. Avoid Non-Native Milkweed

Planting introduced species, notably the tropical milkweed (Asclepias curassavica), also known as blood flower, is not recommended2. It can disrupt the monarch’s traditional feeding cycle, leaving them vulnerable to winter frosts. Its striking, long-blooming flowers also foster the spread of a parasitic, contagious pest of the butterflies. Non-natives can also out-compete native plants that support the local ecosystem.

Plus, Grimm says he’s noticed that non-natives tend to be shorter-lived than natives in the garden, perhaps because they aren’t adapted to local conditions.

3. Site Milkweeds Carefully

Don’t be put off because the plant's name has “weed” in it. While some species may grow quickly, there are no milkweeds on the noxious weed list, according to the U.S. Fish and Wildlife Service.3 However, it’s smart to understand how a particular species grows and spreads in deciding where to plant it. Rampant species might be relegated to raised beds, for example.

Milkweed plants need a full sun location. "A minimum of eight hours of direct sunlight in the summer is ideal," says Grimm.

4. Consider Your Growing Space

“Common milkweed (A. syriaca) is by far the most frequently sown seed,” says Grimm. “The low cost and abundance of the seed make it a great choice for planting out in large areas of the Midwest.” He notes that common milkweed needs room to roam, while in residential gardens, he recommends swamp milkweed (A. incarnata) and butterfly weed (A. tuberosa).

“The clumping growth habit and ease to start from seeds make them a powerful duo for butterfly gardeners seeking a quickly flowering nectar source and host plant for monarch butterflies this summer.”

5. Don't Sow Too Deeply

“Milkweed seeds are simple to sow because they prefer to be near the soil's surface,” Grimm says. “In fact, planting the seeds too deeply is the most common reason the seeds don't grow." He suggests covering the seeds to a depth equal to their width, or just sowing them right on the surface. Grimm also recommends raking or lightly tilling the soil in your planting area first because "the settling soil will hug the seed for successful germination."

6. Expose Seeds to a Cold Period If Needed

Swamp milkweed or butterfly weed, unlike common milkweed, do not need a period of cold stratification to break dormancy. Common milkweed and some other species, on the other hand, need to be planted outside in a prepared seedbed in the fall to accomplish this naturally, as the seeds will bide their time through the winter cold and germinate in spring.

To plant in late winter or spring, mimic outdoor conditions and store your seeds in your refrigerator, wrapped in a damp paper towel inside a labeled zipper bag. Place it in a low-traffic spot in your fridge for three to six weeks, then plant it in pots or a prepared seedbed.

Because their roots are sensitive to transplant shock, planting milkweed seeds directly outside or using biodegradable pots works best.

7. Be Careful with Sap

Milkweeds get their name from the white sap the stalks exude when cut. It does contain toxins that could be dangerous to animals in very large quantities, but it also tastes very bitter, so it is rarely eaten by wildlife. The U.S. Fish and Wildlife Service recommends wearing gloves, supervising children, and keeping it out of livestock’s hay or grazing area.3