While a flower's color, shape or scent will attract butterflies to some degree, the biggest draw by far is the bloom's nectar.
Adult butterflies typically have very cosmopolitan tastes, best served with a smorgasbord of nectar-rich flowers, especially those with flower clusters or daisy-like blooms, such as purple coneflower, mums, yarrow and butterfly weed, as well as tubular or bell-shaped flowers.
Not every nectar flower is suitable as food for butterflies. The amount of nectar a flower produces can vary within the species. Sometimes more fanciful double-flowered varieties are bred to impress the eye and not the appetite. So go with species plants whenever possible, rather than cultivars.
Don't Forget the Caterpillars
In addition to attracting adult butterflies, you can transform any small area into a butterfly nursery. Just grow a few containers of host plants, such as milkweed, mallow or asters. Adult female butterflies lay their eggs on these plants, and young caterpillars feed on them after hatching. Growing caterpillar foods also will bring in more butterflies for longer periods of time. You might even catch sight of species you've never seen before.
Unlike adult butterflies, caterpillars are very picky eaters. As a result, each species seeks out a specific plant or plants for its eggs.
Monarch caterpillars, for example, feed exclusively on milkweed, while skippers mostly feed on grasses, sedges and legumes like wisteria and peas. Host plant preferences can vary within a species. Tiger swallowtails seek out trees like poplars, cherries and tulips, while black and anise swallowtail caterpillars dine on dill, fennel and parsley.
Some winning container combinations to attract several species are milkweed, fennel and grasses; and dogwood and violets with mallow.
With a little planning, you can also make your container garden do double duty. Some nectar sources, like penstemon and nasturtium, also are tasty meals for caterpillars.
Remember that a butterfly container garden isn't limited to patios, decks and entrance areas. Use potted plants to fill in bare spaces in a newly planted perennial bed or garden border. Stagger them on steps, encircle a tree or use them to line a walkway or path. Northern gardeners will need to provide protection for their overwintering plants and shrubs.
One thing is certain: A group of containers in a bright, sunny area can go a long way to providing habitat for butterflies...and a beautiful oasis for you.
