Monarch butterfly on purple coneflower

The monarchs are coming…plant butterfly weed now

Whenever I write this column, I hum “On the way to Cape May.” As a child I remember many day trips to Cape May with my family. I was always a wild flower enthusiast and always noticed the butterfly weed and other wildflowers along the road. Milkweed and other monarch butterfly plants in the asclepias family of plants thrive in the sunny, well drained southern New Jersey fields. The orange butterfly weed, we all love so much, is sometimes called “Railroad Annie” since it grows along tracks and in vacant lots.

What can be prettier than a beautiful summer day filled with garden flowers, fragrance and butterflies? It is not too late to add plants to the garden for butterflies. At the top of the list is butterfly weed or Asclepias tuberosa, which is a form of milkweed.

Butterfly weed is a beautiful fiery orange plant that is now blooming all over southern New Jersey. It has always been one of my very favorite wild flowers. It is known by many different nicknames, but most old timers call it “Railroad Annie” because it often grows along railroad tracks or in vacant fields. Butterfly enthusiasts call it butterfly weed because its colorful blooms attract butterflies. Botanists call it Asclepias tuberosa, which shows how by family name it is related to common milkweed. One can see that the seedpods look similar to the common milkweed, Asclepias syriaca.

Butterfly weed

Some gardeners grow both butterfly weed and common milkweed, which is the host or food plant for the caterpillars of several species of butterflies including the North American Monarch butterfly. It is interesting to know that Monarch butterflies larvae accumulate bitter cardiac glycosides contained in the milkweed plants upon which they feed. Although these are not toxic to the larvae or the butterflies they provide a chemical defense for the larvae, the pupae, and the adult butterflies since they are unpalatable to birds.

Asclepias tuberosa (butterfly weed) has an awesome orange flower, which attracts butterflies to the back boarder around my kitchen garden. Here the plant thrives in the native, sandy soil and readily reseeds among the poppies, gaillardia, potentillia and portulaca since they all grow in sandy, well drained soils. I just added six new plants to this area yesterday. Since it is really sandy I try to water them at least once a week when I water the vegetables in the garden. More than that might rot the plants in most soils that are not sandy

It is easily grown in average, dry to medium moist, well-drained soils in full sun. Drought tolerant it does well in poor, dry soils as well. Plants tends to emerge very late in the spring when the soil warms. Plants are easily grown from seed, but are somewhat slow to establish and may take two to three years to produce flowers. Mature plants may freely self-seed in the landscape if seedpods are not removed prior to splitting open. Butterfly weed should not be dug up as it does not transplant well due to its deep taproot. Buy small nursery grown plants and let them reseed in your garden.

Several other Asclepias species are worth growing for their unusual flowers or decorative seedpods. Swamp milkweed is one that can take moist areas in which to grow. It is identified botanically as Asclepias incarnata, so be sure that you purchase the correct plant for your site and always check the botanical name. This one has a dusty rose flower.

Its common name indicates its preference for a wetland habitat, but this can be a bit misleading as swamps are by definition-wooded wetlands and this plant does best in the sun or at most part sun. It works well for homeowners who have lawn irrigation that makes their gardens too wet for butterfly weed. It will thrive in a sunny butterfly garden that is watered well. It attracts a profusion of butterflies and is an excellent addition to the butterfly garden, as it is both a nectar source and host plant for the Monarch Butterfly.

Butterfly weed

Although aphids sometimes attack it, both in the wild and in the garden (typically on the stem) these are generally not harmful to the plant. They can be removed with a hard stream of water or sprayed with insecticidal soap, or simply left alone. There is always the chance of killing butterfly larvae so I say, let them be. Plant the swamp milkweed toward the rear of garden if you prefer to view the flowers without seeing the aphids.

There are also many tropical plants in this family that are available in the trade. Tropical milkweed, Asclepias curassavica grows to about four feet in height. Two different colors of flowers are available. One is all orange, while part of the flowers of the other type is red. Tropical milkweed is a host plant for Monarch butterflies. Monarch butterflies use milkweed, and only milkweed, as a host plant. Since tropical Milkweed has a high concentration of the poisons that make Monarchs more resistant to predators, they tend to be very attracted to it. Although it is not native to much of the US, many butterfly gardeners like to grow it since the Monarchs like it so much. These often bloom in red, yellow or orange and are often called Mexican or Texas milkweed. Sometimes they will reseed in the garden. Last year I had left over pots of it sitting on my walk way and low and behold the monarch larvae appears and soon made cocoons.

I love all milkweeds, but my favorite is the bright orange tuberosa and I will continue to keep trying to get it growing all over our sandy property. It already grew along the creek and in a few other wild places. Remember butterfly weed is one of our showiest native wildflowers and all members of its family reseed readily if the seeds are allowed to pop open and fall where they may. Nature takes its course, as the old saying goes.

However other plants with daisy-like blooms or tubular flowers also provide nectar. Another native plant that is an aggressive spreader, but one that is often covered with butterflies in fall is the Joe Pye weed or Eupatorium , which is often found growing wild in fields throughout the area. And don’t forget the Buddleia or fragrant butterfly bush (this purple ,white or pink bush is different from butterfly weed or Asclepias) to attract Monarchs and other butterflies. Cut dead blooms off of it often and it will bloom relentlessly. This will also keep it from spreading by seed.

Stop by Triple Oaks or send a self-addressed stamped envelope for common milkweed seeds when they are ready. (Mail to Lorraine Kiefer, c/o Triple Oaks Nursery, PO box 385, Franklinville NJ 08322).