Milkweed is the life-giving plant for Monarchs – it is their sole host plant. The female lays her eggs on it, the caterpillars feed on it and it also serves as a nectar plant for the Monarch and many other pollinators.
There are about 100 types of Milkweed that are native to the United States, but Monarchs will only utilize about 30 of them. Depending on where you live and your hardiness zone, there may be limited choices. Every state has more than one hardiness zone due to climate variations and conditions.
In Zone 6, which covers 38 states from New Jersey to Alaska, and Canada, there are several perennial varieties that are found naturally. Check your local garden center or online for more plants and Milkweed seeds. Be certain they are free from any pesticides and herbacides! Providing clean pesticide-free Milkweed is crucial to the Saving the Monarch Butterfly movement!
Here are three common varities plus a bonus!
1. Common Milkweed (Asclepias syriaca)
Common Milkweeed is what most people think of first; a tall variety with large and fragrant pink flower clusters. This species is best at colonizing; it can be found in fields and pastures, roadsides, ditches and marsh borders. I have found the most caterpillars on Common Milkweed.
Growing Common Milkweed
The root is a rhizome, a large taproot, that does not tolerate transplanting well. Therefore, it is best to grow from seed or some cases, very young plants. Call me lazy, but I have had success only by gathering seed pods (follicle) in the the late summer / early fall and planting the entire pod in the ground. By the following spring, over 50 plants have become well-established.
Good, Bad and Ugly
Many other insects are attracted to Common Milkweed, including the Bumble Bee (Bombus), Milkweed Beetle, other moths and butterflies. However, Aphids, (Oleander Aphids) are a Pest that left undisturbed, will destroy your milkweed, not to mention other plants. They are very common. Two of the best ways to get rid of them naturally is by killing – wear a plastic glove and squish them off the plant (don’t squish the plant!) and clean it with a burst of spray water. Ladybugs also feed on Aphids – you can order them online and they are super-fun to release!
Usually by August, they plant has suffered from insects and heat. It turns yellow (or worse!) and falls over – pretty ugly. At this stage, I begin to remove most of the plant – cut it down to ground-level. I have had no problem with plants re-emerging the following year!
2. Swamp Milkweed (Asclepias incarnata)
Swamp milkweed is a wetland plant but will grow well in medium moist conditions once established. It is an attractive plant with long-lasting pink blooms adored by many pollinators. It does not suffer from the same degree of Aphid infestation like the Common Milkweed, in my experience.
Growing Swamp Milkweed
It grows easily from seed – I have had success with this plant! I have sowed it outdoors in Fall / Winter by sowing the seeds in soil. Have also cold stratified (refrigerate over winter) before starting indoors in the Spring.
Swamp milkweed is well behaved in the garden – it is not invasive as some other milkweeds are. It does get quite large; some gentle support may be needed.
Swamp milkweed is a long-lasting cut flower, at least until it is munched up by caterpillars. It does not wilt as easily as Common and it is a highly recommended addition to your garden!
3. Butterfly weed (Asclepias tuberosa)
Butterfly weed is a cheery bright orange (or yellow) flower that blooms for about two weeks. In my experience, Monarchs prefer other milkweed plants first. It is a valuable nectar plant for Monarchs and other pollenators and is usually readily available at the garden center. They will use it to lay eggs and feed upon, just not as common in my experience.
Tropical Milkweed (Asclepias curassavica)
In Zone 6, Tropical milkweed is a beautiful multi-colored ANNUAL plant and may just be Monarch’s favorite milkweed. It grows and flowers quickly and easily all summer. It also dies at the end of the season.
In Summary, there are several types of milkweed that you can grow in your garden, get from your local garden center, or find it naturally at a park. Just make sure you have a steady supply as you find more caterpillars!
Want to learn more about Monarch Butterflies? Check out TOP TIPS for Raising Monarch Butterflies!