If you long for a garden of colorful flowers -- and butterflies fluttering all around -- it's important to put in the right plants.
Butterflies use or require two different kinds of plants, explains Ed Spevak, curator of invertebrates at the St. Louis Zoo. "You need a host plant for the caterpillars and a nectar source for adults," he says. "So if you are planting a garden for butterflies, you also need to put in plants for the caterpillars."
Simply put, female butterflies locate and lay their eggs on plants that caterpillars can use for food. So if you don't provide host plants, then you'll naturally have fewer butterflies, Spevak says.
Some plants work well for both caterpillars and butterflies. "You have to look at the species. For example, when you are looking at the monarch, you can plant milkweed," he says. "Milkweed is a good host plant for caterpillars and a nectar source for adults." It is also a good nectar plant for black swallowtails.
The aptly named butterfly bush is available in purple, white and magenta. "You have to be a little careful of the butterfly bush because it can be invasive and kind of take over," Spevak says. "A lot of gardeners trim them back in the fall." Additionally, marigold, one of the easiest plants to grow, attracts monarchs and black swallowtails.
Some people think zinnias -- which are also easy to grow and pretty in any garden -- are butterfly magnets. However, Spevak says he isn't too sure about that. "I do know that if you have a nice color flower that means it is attracting something," he says. "Hummingbirds are attracted to the color red and to tubular shaped flowers. Bees and butterflies like yellows and purples."
Sometimes you don't even have to plant flowers to attract butterflies. White clover, which grows naturally in lawns not treated with pesticides, will attract buckeye butterflies and some beneficial bees, as well, says Spevak. "Clover is great in a lawn because it adds nitrogen," he says. "And I tell people if you don't bother bees they won't bother you. When bees are in a garden, they are only interested in eating."
As far as other host plants go, you can plant dill, parsley and fennel to feed black swallowtail caterpillars and snapdragons to feed hungry buckeye caterpillars.
Keep in mind that caterpillars will chew and chew, so your host plants won't look perfect. You might want to locate host plants in a slightly less visible spot, while still keeping them fairly close to the nectar plants.
Remember that where you plant the nectar flowers matters, too. Butterflies like plants that are in a sunny location but sheltered from the wind. When they aren't traveling from plant to plant, butterflies will often land in a warm spot -- so place a few flat rocks around so they can sunbathe for a while.
Finally, when the warm sun and all that flitting around make them thirsty, your butterflies will be looking for a nice drink of water. That's why it's a good idea to keep a bucket with sand nearby; make sure there is just enough water in it to make the sand moist.
Spevak recommends planting your garden so you'll have flowers from spring until fall. For more information on what and when to plant in your area, go to these websites: http://www.xerces.org and http://www.pollinator.org.