Back Issue
July/August 1999

Connecticut Butterfly Gardens

The Bird & Butterfly Garden at Lockwood Farm, Kenwood and Evergreen Avenues, Hamden. Open Monday-Friday, 8:30 am-4:30 pm; closed state holidays. Free admission.

The Butterfly Garden at Dinosaur State Park, West Street, Rocky Hill. Open daily 9 am -4:30 pm; 860-529-5816. Free admission to the garden; $2 adult admission to exhibit center.

Butterfly Garden Basics
by Pamela Weil

Whether it's only a few plants outside your kitchen window, or a large area in your backyard, creating a haven for butterflies will bring you immeasurable joy. Any butterfly garden, whatever its size, must provide sun, shelter from winds, and food for the butterfly in its adult and larval (caterpillar) stages. Locate your butterfly garden away from bird feeding areas and include a "puddling" area (more about this later).

Your butterfly garden must be in a location that's warm and sunny most of the day. On cool days and in the mornings, butterflies bask in the sunlight. The sun increases their body temperature, which must rise to 85-100 degrees F before they can fly. This is why butterflies are active on sunny days and inactive on cloudy days. Add a few light-colored stones or rocks to your garden for the butterflies to use as basking sites.

On gusty summer days, butterflies need protection from the wind. Tall flowering perennials or shrubs at the back of the garden will block the wind and protect the butterflies while they are nectaring.

If you're just starting to learn about butterflies, begin with a regional field guide. Jeff Fengler of the Connecticut Butterfly Association (CBA) recommends Jeff Glassberg's Butterflies Through Binoculars, which only covers the species found in the Washington D.C. to Boston region. This is so you won't be overwhelmed by multitudes of similar looking species, many of which are not found in our area anyway, that a guide for all of North America would contain.

Nectar Plants
Flying requires great amounts of energy which adult butterflies receive from nectar-producing flowers. Nectar contains energy-rich sugars and lipids and has about the same basic chemical make-up, no matter what flower it comes from. A hungry adult butterfly may visit several different flowers for nectar. However, some butterfly species do have nectaring preferences.

Host Plants
Butterflies lay eggs on host plants and later, when the eggs hatch, the larvae (or caterpillars) eat the leaves: they require a different menu than adult butterflies. Most adult butterflies lay their eggs on or near specific plants because these plants meet the nutritional needs of the larvae or caterpillars hatched from the eggs. The specificity is apparently so strong that most caterpillars will starve to death if they cannot find their host plants in a field or yard soon after emerging from the egg. Monarch larvae, for example, only feed on plants in the milkweed (Asclepias) family.
Many larval host plants are either weeds or weedy looking, such as common milkweed (Asclepias syriaca), dandelion, dogbane (Apocynum spp.), white clover, vetch, stinging nettle (Urtica dioica) and thistle. Not attractive to begin with, they are even less attractive after being eaten by the caterpillars, which feed voraciously for a few weeks before forming a chrysalis.
Consequently, I prefer to locate the breeding and feeding ground in a patch of wild vegetation in a corner of my property, near but not with my more formal butterfly nectar garden. Here in this"wild" garden, plants that are nectar rich but invasive ( beebalms and some of the goldenrods, for example) can also spread at will.
Not everyone agrees with this separate-but-equal treatment. "Larval and host plants can really look great planted side by side," CBA member John Himmelman says. "To see an example, visit the butterfly garden at Dinosaur State Park in Rocky Hill."

Puddling
Create a puddling site in your butterfly garden, which is a bare patch of soil where water can regularly accumulate and then evaporate, thus concentrating minerals in the soil. Puddling is a behavior mainly practised by male butterflies, who gather to extract nutrients, especially sodium, from the mud.
A few rocks coming out of the mud will provide something for the butterflies to sit on. "Keep the area bare and hose it down once in a while," says Himmelman, "that's all you have to do."

Don't Use Pesticides
Pesticides kill butterflies. Even organically acceptable pesticides such as rotenone and pyrethrin kill butterflies and their larvae. The bacterial insecticide BT (Bacillus thuringiensis) will kill butterfly larvae.

Instead of using pesticides, handpick insects or knock them off with a strong jet of water. Control aphids with homemade sprays of soapsuds, garlic, chives, and/or Tabasco.

Choosing Plants
What to plant is the question. Butterfly plant lists are plentiful; just open any book about butterflies. There are so many choices that deciding what to plant can be confusing, even overwhelming. And shouldn't we in Connecticut plant what Connecticut butterflies need? And how do we know what that is?

Happily for us, information is available from the Connecticut Butterfly Association. Three active CBA members — Christine Cook, John Himmelman and Carol Lemmon — provided information for this article.

Planting a garden specifically for one butterfly species isn't a good idea. "Some butterflies, such as Hackberry Emperor and Tawny Emperor, are very colonial and may not be in your area," says Christine Cook. "We don't know why that is: why they can get used to one location and not want to move to another."

The best approach is to choose plants that will supplement the larval food sources that are already growing in your own backyard. Larval food sources are often shrubs and trees. In my backyard, for example, there are willow and black cherry trees; both are larval food sources for the Eastern Tiger Swallowtail. So if I plant some nectar sources that Swallowtails will like, chances are good that I will be rewarded with Swallowtail visitors. Larval and food source information can be found in many butterfly books. And the CBA publishes a variety of readily available reference materials on the needs of Connecticut butterflies.

If you prefer a more openended approach — the more butterflies the merrier — choose plants that will consistently attract large numbers of many different butterfly species. "The Best Perennials and Shrubs for Connecticut Butterflies" is a collection of plants that are favorites of the three CBA members; most are native to North America. Which should be no surprise, when you think about it. "These are native butterflies," says Himmelman, " and it makes sense to offer them the plants that they evolved with."

The butterfly nectar garden plant list includes perennials and shrubs that bloom from early spring through frost because butterflies need nectar throughout the year. And an ideal garden should have grasses and sedges. "Many butterflies," says Lemmon, "including almost all your skippers, feed on grasses and overwinter in them." It does not include annuals, although many are excellent (heliotrope and zinnia, for example).

Most of these plants require some sun and well drained soil. But if you have different conditions, don't despair. John Himmelman attracts butterflies to his sunny water garden with pickerel weed, turtlehead (Chelone), buttonbush, cranberry, and milkweed. In a shady fairly dry spot, Christine Cook recommends spicebush and Joe-Pye weed.

Some enthusiasts believe that butterflies prefer dark colors, deep purples and pinks, over white. But who knows. "Some people swear by their purple butterfly bush," says Cook. "Others swear by their white." And whatever you plant, plant lots of it. Not one here, one there. "Six of something is more attractive to the butterflies," says Cook.

Don't plant any species in your butterfly garden, however attractive to butterflies, that is potentially invasive. Invasive plants still being sold by some Connecticut nurseries include purple loosestrife, yellow flag iris and honeysuckle. Sometimes a specific plant is described as "sterile" or "non invasive." Don't believe it, and don't plant it. "Invasive plants harm butterflies by taking over their habitats," says Lemmon. "Instead of a field of native plants species that would provide nectar sources for butterflies from April until December, a field of one plant might only provide nectar for just two short weeks."

Native Plants vs. Cultivars
Many of our native plants have been "improved" by plant breeders. Whether or not the newer cultivars really are an improvement can be debatable. And what to plant — these newer "improved" cultivars or their native parents — is also controversial.

These "improved" cultivars may offer a better habit, longer bloom time, more flowers and/or larger flowers than their native parent. But they may not be as beneficial to the butterflies. Or, they may be better. Three examples of outstanding cultivars are the New England aster 'September Ruby', Rudbeckia 'Goldstrum' and Joe-Pye weed 'Gateway'. To further complicate the matter, some exotic plants are fine, too. Butterfly bush, for example, is not native to North America.

Evaluate each plant on its own merits. In general, stay away from plants with double flowers. "When you breed something for one expression, you may lose out in another," says Lemmon. "The double blossom may make it difficult for the butterfly's proboscis to find the real nectar source." The flower may have lost its scent; the nectar may not be of the same quality. We humans have no way of knowing.

Christine Cook is a landscape designer in Easton, CT whose company Mossaics specializes in backyard habitat restoration.
John Himmelman has written and illustrated over 50 children's books, many with nature-related themes.
Carol Lemmon is the Deputy State Entomologist for the Connecticut Agricultural Experiement Station.

Connecticut Gardener
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