Milkweed In Your Garden

Should I plant milkweed?

There are a couple of reasons to consider planting in your landscape. Vibrant blooms are certainly one of them; as they will add a wonderful pop of color to gardens with clusters of flowers that range from hot pink to bright orange to soft white. But there’s another reason so many people are planting it now.

You may have heard that milkweed is important for monarch butterflies. While it is a source of nectar for them, it’s more than that, it is actually a necessary host plant for them. This is because the monarch butterfly caterpillar only eats milkweed, and this is why mature butterflies only lay their eggs on them. Without these host plants, the caterpillars will starve. Planting milkweed is such a simple way to help the monarch butterfly population!

Where to plant?

Different varieties of milkweed thrive in different conditions. Common milkweed, for instance, will thrive in most gardens and enjoys average soil. Swamp Milkweed, on the other hand, will thrive in moist soil and would be perfect in a rain garden. It’s important to research each variety before planting to know if it will work well with your zone and planting conditions.

Once you’ve determined what conditions your plant needs to thrive, plant them somewhere you (and butterflies) can enjoy them! Since they do grow quickly, they may overwhelm more formal gardens, so it is best to plant them in more naturalistic settings, such as meadows.

Isn’t milkweed toxic?

Milkweed secretes a milky sap (hence its name). This sap can be harmful to humans, pets, livestock, and other animals—but only if it is consumed in very large quantities. Fortunately, the sap tastes so foul that most critters (monarch caterpillars excluded!) are more than happy to leave the entire plant alone.

Is milkweed invasive?

Milkweed is often seen as an invasive weed. Truthfully, although “weed” is in the name, it is not a weed at all, and over 100 varieties are native to the US! While it is not a weed, it does grow very quickly, so you’ll want to maintain it to make sure it doesn’t quickly outgrow the planting spot you’ve chosen. Be prepared though, as caterpillars will readily handle pruning if present.

Caring For Milkweed

Milkweed is very adaptable and self-sustaining. Many varieties are hardy from zones 3 to 9 and are happy in any type of soil without fertilization. Younger plants will enjoy lots of sun as they start to grow, but multiple varieties can tolerate almost any conditions once they are well-established.

How should I prune?

Milkweed does not need to be pruned or trimmed. You can deadhead (remove dead flowers) them to prolong their blooming period and remove the dandelion-like seed pods to prevent excessive spreading. Also, keep in mind that caterpillars will likely strip the leaves from your plants, so you may want to cut them back to about six inches above the ground to encourage quick growth.

How do I water?

For many varieties, you don’t really need to! As long as your area is not prone to drought, you can leave your plants alone and they will do just fine. For swamp milkweed varieties, you will need to regularly water them or make sure they are planted in a moist environment.

How do I care for milkweed over winter?

While select varieties, such as butterfly weed, will enjoy the protection of a little mulch during colder months, most varieties require very little winter care. Once the plants start to die back in the fall, you can trim them all the way down and wait for them to re-emerge in spring.

Common Milkweed Problems

They are quite resistant to disease. However, they may occasionally be prone to a few pests, and some varieties (common milkweed, for instance) may get crown rot if soil is too moist.

Dealing with aphids and other pests

Aphids (often very small and bright orange-gold in color) suck sap from plants. To deal with a severe infestation of aphids, spray plants with cold water (but be careful not to harm any monarch butterfly eggs in the process). Cold water should be sufficient in removing aphids; if it does not solve the problem, you can spray affected plants with insecticidal soap. This should only be done if absolutely necessary.

These plants are also extremely attractive to slugs, which will eat holes in the leaves and badly damage flowers. If you see large holes in your plants’ foliage, check for slugs in the evenings. Dropping slugs into a bucket of water mixed with dish soap is an effective and mess-free way to remove these pests from your garden.