How Butterfly Gardens Work

Few animals spark imagination and creativity as much as butterflies do. Robert Frost bent down to study a "dye-dusty wing" nestled in dead leaves and wrote "My Butterfly," the poem that later made him famous. Emily Dickinson penned at least nine poems about the creatures and their "pretty parasols." Poetry aside, who can forget Muhammad Ali's famous claim to "float like a butterfly, sting like a bee?"

Poets and casual observers may be content to watch these winged insects flit among flowers in the wild, but others are not. As habitat loss and pesticide use decrease butterfly numbers, enthusiasts are turning to butterfly gardens as a way to attract and conserve the species.

Conserving butterfly habitat indirectly benefits humans as well. Because of butterflies' intimate relationship with their environment and their sensitivity to changes in the surroundings, they are important indicators of an area's health. Similar to the historic "canaries in a coal mine," the declining health of butterfly populations can alert people to a problem in the ecosystem.

Along the same vein, butterflies play an important role in scientific research. Much of what we know about mimicry, evolution, animal behavior and how organisms interact with one another we learned from studying butterflies. In fact, the discovery of the inheritance of the Rh blood factor (responsible for clotting blood) and its potentially deadly effects in humans came from studying an African butterfly [source: Schappert].

Perhaps the most obvious and popular reason to start a butterfly garden is for pleasure. Bright, blooming flowers, flapping wings in a rainbow of undulating colors- -- what's not to like? If creating one can be as simple as a quick stop by the neighborhood nursery, why not?

In this article, you'll learn what caterpillars and butterflies need to survive, determine the requirements of a butterfly garden and gain a few tips on how to create a thriving butterfly sanctuary of your own. But first a quick word on butterfly biology and why caterpillars have the biggest appetite in town.

Butterfly Background

Before you can create a butterfly garden alive with a profusion of delicately fluttering wings, you need to know a little about butterfly biology, including how they survive and reproduce.

When designing a butterfly garden, remember that butterflies are not always so attractive. They spend a crucial portion of their lives as caterpillars. The caterpillar, or larval, stage functions as the growth period. It may last as long as three years in colder climates or as briefly as 12 days in warmer ones. Caterpillars eat constantly, shedding their skin four or five times as they continually outgrow it, like kids in the thick of a growth spurt. Feeding mainly on leaves, caterpillars balloon to one thousand times their initial size by the end of the larval period [source: Dole].

Although caterpillars may eat with abandon, they often are highly picky. Some species only eat one type of plant. These preferred plants are called host plants, and you want to make sure you stock plenty of them in your garden. While it's true that different species will like different plants, typical host plants are weedy ones like clovers, nettles and dill.

Asters are a good nectar plant for butterfly gardens.
Garry Gay/Getty Images

Butterflies look out for their younger counterparts by only laying their eggs where emerging caterpillars are assured an abundant food source when they hatch. Females often fly from plant to plant, smelling with their antennae and tasting with their feet until they find the right spot. If females can't find the appropriate plant, they will not reproduce, so placing host plants in your butterfly garden is important.

Soon after a caterpillar transforms swan-like into a butterfly, it flies off in search of a mate. Just as the caterpillar phase is primarily for growth, the adult butterfly phase is primarily for reproduction. Butterflies do not grow. Rather than gobble down leaves for growth, butterflies mainly consume nectar for energy to fly. They find their food in flowering plants called nectar plants. Preferred nectar plants tend to be bright and colorful flowers where the nectar is easily accessible. Single petal flowers with short tubes and wide flat rims are a safe bet; phlox, verbena and flowers in the daisy or aster families are usually good choices. Successful butterfly gardens must incorporate a variety of both host and nectar plants.

In addition to catering to the energy needs of a butterfly's different life stages, butterfly gardens also need to account for the different hazards the insects may face, like a swarm of fierce fire ants. On the next page, you'll learn what types of threats caterpillars and butterflies might meet and how your garden can help to protect them.

Threats to Butterflies

Even in a butterfly garden, both caterpillars and butterflies will encounter their fair share of tough breaks. During the larval stage, caterpillars (or larvae) are easy prey for fire ants, birds, flies and wasps. A faction of fire ants can devour a caterpillar in minutes. Funguses caused by damp, overcast days also endanger larvae, as does a loss of plant life caused by poor weather.

Butterflies have their own enemies: Birds, small mammals, lizards, snakes and spiders all prey on them. Extreme weather is another enemy of the cold-blooded animals, which are highly sensitive to temperature. At 40 degrees Fahrenheit (4 degrees Celsius) butterflies are completely immobile, and they can't fly until their internal temperature reaches 82 degrees Fahrenheit (28 degrees Celsius) [source: Ajilvsgi]. In addition, harsh winds and rains can beat butterflies down and drown them. Finally, both butterflies and caterpillars are sensitive to pesticide and herbicide use. Even the commonly used biological control agent Bt, often promoted as "safe and natural," poses dangers. Butterflies are so sensitive to pesticides that pollen from corn genetically modified with Bt has been transferred to other plants downwind and been shown to kill monarch butterfly larvae [source: Schappert].

Butterfly gardens can reduce these hazards, though, by providing a pesticide-free environment with easy access to sunlight and sheltering spots. On the next page, you'll learn in more detail how you can help caterpillars and butterflies thrive, and you'll also discover the four basic needs of every butterfly garden.

Famous Butterfly Gardens

Public butterfly gardens and observatories are popular tourist attractions, drawing millions of visitors each year. In the United States, the Cecil B. Day Butterfly Center in Pine Mountain, Ga., plays host to 1,000 tropical species of butterflies from at least 50 species in a recreated rainforest environment spread over 4.5 acres [source: Callaway Gardens]. Farther south in Costa Rica, you'll find the largest butterfly observatory in the world, with more than 4,000 butterflies from 20 different species. At the La Paz Wildlife Garden National Park and Wildlife Refuge, visitors can observe all the stages of a butterfly's life cycle in a laboratory. The refuge claims that up to 55 percent of the butterflies reach adulthood, compared with a 5 percent survival rate in the wild [source: La Paz].

Butterfly Garden Design

With the knowledge you have gained so far about butterflies, you can easily design a sanctuary to cater to their primary needs: plants, shelter, sun and water.

The particular types of host and nectar plants necessary depends on what geographic region your garden is located in, as well as which butterflies are native to your area, but there are a few rules of thumb:

Plant flowers in groups, as opposed to singly.
Plant flowers in layers at various heights.
Use native plants that are already conditioned to your region, as they're more likely to be good nectar sources.
Plant a variety of flowers with different blooming cycles so the garden will be productive year-round.
Spread out host plants so as not to attract predators to the groups of eggs or larvae.
Keep seeds or potted plants readily available in case of plant loss.

Butterflies get many necessary nutrients from the soil by way of puddles.
© iStockphoto.com/Pierre Yu

As you learned on the previous page, both caterpillars and butterflies are susceptible to harsh weather conditions and predators. Thus, they need a place to go to escape these threats. Plants should be spaced so that caterpillars and butterflies can readily find shelter under their leaves from predators, intense sun or rain. Caterpillars and butterflies may also rest in leaf debris or under fallen logs, especially in cold weather, so butterfly gardening is one area of your life where messy really is better. Butterfly gardens require less upkeep than manicured lawns because the more natural they are, the more attractive they look to butterflies. Cleaning up fallen leaves and debris may actually take away some of their hiding places.

Because butterflies need warmth to function, it is essential that butterfly gardens receive lots of sun. Butterflies often bask on rocks or logs with their wings outspread to absorb the sun's warmth. It is helpful to strategically place items that can be used as resting spots so they have a place to get early morning sunlight and/or late afternoon rays.

Like all animals, butterflies require fresh water regularly. In addition, they often need to consume salts and amino acids that they don't receive from the nectar they drink. They can often get those things from soil in the garden. Letting water drip onto a spot of bare soil will create a puddle where butterflies can congregate and drink in the necessary nutrients missing from their diets.

Plants, shelter, sun and water -- pretty easy, right? It's basically an ordinary garden with just a little bit more planning. But where to begin? Read the next page for some simple tips on creating a butterfly garden of your own.

How to Make a Butterfly Garden

So you want to create your own butterfly garden and you're not quite sure where to start. Here's a quick outline of how to begin.

Research

Your first assignment is to find out what butterflies are common to your area. One way to do this is simply to observe your surroundings for several days, noting what kinds of butterflies you see and identifying them by looking in an identification guide. From there you should investigate the types of host plants and nectar plants that will attract and sustain those species of caterpillars and butterflies, respectively. You can find lots of information about the regions and plants different caterpillars and butterflies prefer on Web sites like thebutterflysite.com or in a guidebook such as Claire Hagen Dole's "The Butterfly Gardener's Guide." Try to select native plants and remember to pick some plants for each growing season.

Plot

Your second task is to decide where you want to plant your garden, keeping in mind that it needs to be a sunny spot. You should also pay attention to whether the desired area is subject to gusty winds or hard rain. If it is, put up some sort of barrier, like a fence or a grouping of shrubs, so future residents can seek a respite from the elements.

Plant

Once you know what you're going to plant and where, the real fun begins. As with all gardening, the soil is important, so you may want to consider amending your soil (or incorporating some new soil into your own to improve it) if necessary. In addition, make sure you are planting in an area with proper drainage, so huge puddles don't form when it rains, which would endanger the plants, as well as the butterflies and caterpillars. You can buy your plants at a local nursery, get cuttings from a friend or neighbor or look for wild specimens growing in abandoned lots. As you plant, keep in mind the guidelines from the previous page -- mainly that groupings of flowers are most attractive to butterflies and that it's best to plant in layers grouped by height.

Once you have your garden planted, it's just a matter of upkeep. Keep reading to ensure your butterfly garden stands the test of time.

On the Rocks?

Butterflies sometimes eat more than flower nectar. They may feed on overripe fruit, tree sap and even carrion and dung. You can create your own homemade nectar by following a process known as sugaring, which produces something that, at first glance, looks like a concoction you might be served at a quirky bar. Sugaring involves combining one can of beer, a pound of sugar, a half cup of dark molasses and some very ripe fruit (and maybe a dash of rum) in a blender and allowing the mixture to thicken to a spreadable consistency. After letting the tantalizing elixir ferment for about a day, you brush it onto tree trunks or posts or place it in a dish on a flat surface and then wait for the butterflies to arrive.

Butterfly Garden Maintenance

Like any garden, your butterfly garden will require some upkeep, but with a few special considerations. First, remember that butterflies are sensitive to pesticides of any sort, so you will have to discourage any unwanted guests through natural means. This means either letting nature’s pesticides, such as spiders and wasps, do the work for you or using natural products, such as insecticidal soaps or plant-based oils. You’ll also want to remember not to get too gung-ho about weeding because many weeds actually serve as caterpillars’ favorite grub. If hard freezes or droughts kill off any of your plants, be ready to substitute with some potted ones if necessary.

In fact, if you want to bypass the planting steps altogether, you can create a butterfly garden solely using container plants. Just visit your local nursery, buy native container plants for the butterfly species in your area, place them in a sunny spot with access to shelter and -- voila -- you have a butterfly garden.

As you can see, butterfly gardens are not terribly complicated, but they are extremely rewarding. Soon after planting, you will begin to see butterflies more frequently -- butterflies can detect food from miles away. Once they know they can count on your garden to provide them with both a source of nectar and a place to lay their eggs, they will likely stick around. Many butterflies spend their entire lives in one area, so you may even watch a butterfly complete its entire life cycle in your own backyard. Other butterflies may migrate in the winter or travel more widely, but as long as you continue to provide a welcome sanctuary for these winged creatures, their offspring will reward you with their presence.

For more interesting information about butterfly gardens and some good resources for creating one, check out the links on the following page.

Bothersome Butterfly Bush?

Plants in the genus Buddleia, commonly known as butterfly bush, are popular choices in butterfly gardens for an obvious reason: They’re magnets for butterflies. This colorful shrub is especially hardy. It tolerates pollution and less-than ideal soil and grows quickly. It is semi-evergreen in warmer climates and typically reaches heights of 6 feet to 12 feet (1.8 meters to 3.7 meters) and widths of 4 feet to 15 feet (1.2 meters to 4.6 meters). Its 1-foot or 2-foot (0.30-meter to 0.61-meter) blossoms resemble lilacs and can easily support even the largest of butterflies. Despite all it has going for it, many garden groups have blacklisted the non-native plant as an invasive species, citing its reputation as a weedy colonizer that often grows at the expense of less hardy native species [source: Dole].