Downy Yellow Violet
Warm weather brings incredible insect activity. Armies of ants march to and fro around patio doors, Carpenter Bees drill holes in house siding, Cabbage White caterpillars devour newly planted broccoli.
In the face of so much potential insect damage, it is important to remember that butterflies are also insects, which can be harmed by indiscriminate use of household pesticides. Consider using non-pesticide methods for insect control around the house and garden when possible. If non-pesticide methods are not available, use highly specific pesticides applied directly to the targeted pest or its location. Netting can protect broccoli, Carpenter Bees can be managed with traps and localized treatment of their entry holes, and the legion of ants might surrender with bait applied directly to their nest or trail.
While ants can be a problem inside a house, outside they play an important role in spreading seeds of many beautiful flowering plants, some of which benefit butterflies. Mary Ann Borge explains in “A Carpet of Spring Beauty, Woven by … Ants!” how as many as thirty percent of spring flowering plants in the forests of eastern North American may have their seeds distributed by ants.
Violets, which are a caterpillar food plant of Fritillaries, are just one of the many spring flowering plants that are spread by ants. Violets do spread (by ants!) throughout the garden but are easily managed with a hoe and a bit of patience.
Northern Spicebush Flowers
It is Spicebush season in the butterfly garden. In the spring, Northern Spicebush is one of the first native shrubs to bloom. The flowers of Northern Spicebush are numerous, pale yellow, lightly fragrant, and, under the right weather conditions, can bloom for up to two weeks.
Fitting Northern Spicebush into a garden is easy. Shrubby by nature, it can be kept to a small size by cutting back the larger branches every so often. It can even be cut back to the ground, with new growth coming back as a profusion of twiggy stems. In fact, older large bushes tend to become brittle and benefit from a trim before limbs break under winter snow loads.
Northern Spicebush as a small shrub
Butterflies do not often visit Northern Spicebush flowers for nectar; other small insects, including bees and flies, primarily cross-pollinate the spring flowers. Starting in late spring or early summer, the Spicebush Swallowtail will lay eggs on the Northern Spicebush leaves. The resulting caterpillars will feast on the leaves until it is time for them to pupate.
Northern Spicebush as a small tree. Notice that older thick branches have been sawed off or broken in heavy snow.
Spicebush finishes the garden season with colorful leaves. If you happen to have both a male and female Northern Spicebush in your garden, fall will also bring on a brief display of red berries on the female Northern Spicebush. Look for the berries in late summer to early fall. They are a favorite food of many birds and mammals so they will not be left on the shrubs for very long.
Eastern Tiger Swallowtail on Black Cherry
Many trees and shrubs offer caterpillar food and are therefore important to include in a butterfly garden if you wish to help increase butterfly populations. Of course, trees and shrubs are not always the easiest plant to fit into a garden, yard, or balcony!
Whether you are short on space or simply don’t have the interest in growing trees and shrubs, you might still want to take inventory of trees and shrubs in your area which could be important caterpillar food plants. Even if you are only able to provide nectar plants in your yard or garden, knowing the full life cycle of butterflies in your area will enrich your experience butterfly watching experience.
Spring is the best time to examine your neighborhood trees and shrubs and requires no trespassing. During the spring blooming period, it is often easy to spot a tree or shrub at a distance that might otherwise go unnoticed during the rest of the year.
Two trees that are easy to identify during their spring blooming period are Northern Spicebush and Black Cherry. While Northern Spicebush provides caterpillar food for only one butterfly, the Spicebush Swallowtail, Black Cherry is happily devoured by Eastern Tiger Swallowtail, Red-spotted Purples, and Coral Hairstreaks.
Look for Northern Spicebush with its early yellow flowers that cling closely up and down each branch and blooms early in spring. Black Cherry blooms later than Northern Spicebush. It is a tall tree with drooping white flowers that are easily seen at a distance.
Monarch caterpillar on Tropical Milkweed
Planting milkweed for Monarchs is one of the important first steps in starting a butterfly garden this spring.
Once you have decided to plant milkweed, the next step is to choose which type of milkweed will be best for your site. Monarch Joint Venture has a brochure that details the milkweed species that are native to the central United States. Some of the milkweed species in the brochure can be hard to find in local nurseries but are worth searching for.
If you have not already started your own native milkweed plants from seed, the milkweed variety that you plant this year will depend on what is available at plant nurseries. While there are about 100 species of milkweed native to the United States, very few are commercially available. Swamp Milkweed is often found for sale, as is Butterfly Milkweed.
In many parts of the United States, Tropical Milkweed is the milkweed most commonly found for sale. Not native to the United States, it is an attractive plant with bright red or yellow flowers. It is easy to grow from seed and is the always the first milkweed in my garden to have Monarch caterpillars happily munching away on its leaves. If started from seed in spring, it could be late summer before flowers arrive but in the meantime it will be a source of tender milkweed leaves that are very attractive to egg laying Monarchs. Many years, my stand of tropical milkweed has very few flowers because the plants are eaten down to the stalk by hungry Monarch caterpillars.
Many butterfly gardeners feel that Tropical Milkweed is a problematic milkweed due to the Monarch parasite Ophryocystis elektroscirrha (OE). The parasite is transferred as a spore, moving from milkweed to milkweed attached to the adult Monarch’s abdomen. The buildup of this parasite in Monarchs can limit their life span over time. In parts of the southern United States where Tropical Milkweed is grown as a perennial, to avoid a buildup of OE spores it is suggested that Tropical Milkweed be grown as an annual (by removing plants each year), cut back to the ground once or twice a year, or not grown at all.
Find more about milkweeds on nababutterfly.com’s Monarchs and Milkweed page.
One of the earliest perennial plants to emerge in the spring in my NJ butterfly garden, Golden Alexander (Zizia aura) is becoming one of my favorite plants.
Easily started from seed two years ago, Golden Alexander has multiplied (without any aggressive tendencies) and seems to be one of the very few plants that my neighborhood deer do not enjoy. Black Swallowtails use Golden Alexander as a caterpillar food plant, but to date, Black Swallowtails seem to prefer the parsley that I grow over Golden Alexander. This year, now that I have a larger number of Golden Alexander plants, I imagine that the Black Swallowtails might take some notice.
Even though Golden Alexander is waking up from a long cold winter, it will still be weeks before many of the plants in my butterfly garden reappear. One of the latest to emerge in the spring are milkweeds, often not poking through the ground until early May.
Eastern Tiger Swallowtail nectaring on Butterfly Bush
Does Butterfly Bush have a place in butterfly gardening? It depends. The topic has been widely debated. Depending who you ask, it is either the best thing since sliced bread or the plant that will destroy the entire ecosystem of North America.
North American Butterfly Association publishes two magazines for its members: American Butterflies and Butterfly Gardener. In the summer of 2012, an entire issue of Butterfly Gardener was devoted to the pros and cons of Butterfly Bush. The entire issue has been posted on the NABA website in order to help each person be better informed about the use and misuse of this plant in butterfly gardening and home landscaping. Read the entire issue
Viceroy on common buttonbush
Groups of plants have been selected and rated by NABA members as important native plants for butterfly gardening. Be sure to check NABA’s Regional Garden Guides to learn which plants are best suited for butterfly gardens in your area.