monarch butterfly Archives

Three Common types of Milkweed for Monarch Butterflies in Zone 6

by cherylfleishman | Jul 20, 2020 | Photography Tips

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.

When you break the stem or a leaf, a white sappy liquid emerges – Milkweed contains toxins (cardiac glycosides or cardenolides) that can be harmful to pets, livestock and people if consumed in large quantities. Another reminder to Wash Your Hands! After handling milkweed, clean up any spillage that may occur, before touching your pet (or your face!).

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.

Cuttings

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.

Image by James DeMers at Pixabay

Once it is well established, it very dependable and well behaved in the garden. Like many other Milkweeds, Asclepias tuberosa produces a strong taproot which is difficult to transplant but also tough and tolerant in dry conditions.

Bonus!

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.

The problem is that Tropical Milkweed is NOT NATIVE to the US. It has been naturalized in zones 9-11 (and possibly 8b) where it grows as a perennial. In these temperate zones, it does not die back in the winter. Therefore, parasites of the Monarch, “OE” (Ophryocystis elektroscirrha) can travel with Monarchs and the plants they visit. Newly hatched caterpillars eat these plants and ingest the OE. Lower migration success, stemming from developmental issues, are a result of high OE levels in adult Monarchs. Because Tropical Milkweed remains evergreen through winter, OE levels build on the plant over time. Therefore, future generations of monarch caterpillars feeding on the plant can be exposed to dangerous levels of OE.

Always plant NATIVE species to your zone, or grow as an annual.

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!