July 8, 2004

In the Garden

Butterflies

by AMY STEWART

[swallowtail butterfly] I'VE ALWAYS CONSIDERED THE PRESENCE OF BUTTERFLIES IN the garden to be a pleasant bonus, a small reward, for planting the kind of garden that is attractive to winged creatures of all kinds. But in the last year, as I've cut back on the amount of space devoted to vegetables and made room for more flowers, butterflies have become a central focus of my garden. I'm a sucker for any plant that is rumored to attract butterflies, and I've been known to follow a swallowtail down the street in an attempt to discover its favorite food source.

At first, it seemed like the butterflies would never show up. Swallowtails flitted past the buffet I'd set out for them, oblivious to my attempts to persuade them to stop for a visit. A monarch appeared once or twice, but seemed equally uninterested in sticking around for a meal. Even the more common West Coast lady wasn't turning up in great numbers.

But now that summer's in full swing, that's all changed. Butterflies are such a common sight in the garden that I hardly look up when one of their translucent shadows moves across the patch of weeds I'm pulling. They've discovered all the flowers I planted for them. With any luck, they'll tell their friends and I'll be a stop on the nectar trail for years to come.

The most important thing to know about planting a butterfly garden is that butterflies are interested in two kinds of plants: larval plants and nectar plants. Monarchs, for instance, lay their eggs on milkweed, and when the caterpillars emerge, they eat the milkweed leaves, which have the added benefit of supplying them with a dose of toxins that will make them poisonous to predators. Anise swallowtails often use fennel as a larval plant, and the Western tiger swallowtail, which is the one you're most likely to see around here [in photo above] , prefers large riparian trees like cottonwood, willow, wild cherry, aspen and ash. You may not have the space or the inclination to grow larval plants for caterpillars, but you can still supply the adults with a source of nectar.

I'll list some of my favorite nectar plants for butterflies, but in general, any plant that produces clusters of small flowers will attract butterflies and other small, winged insects. Look around your neighborhood and see what plants the butterflies are visiting -- they'll go more readily to a food source that's familiar. They also like a solid landing spot, so flat-topped flowers on sturdy stems are a good choice. Finally, remember that butterflies need a water source, too: You may see them searching for a muddy puddle where they can draw up water and minerals.

Butterfly bush (Buddleja): With a name like that, how can you go wrong? Colors range from pale pink and lavender to deep purple, and there is even a yellow and orange variety called "Honeycomb." A butterfly bush can grown to over 10 feet tall and needs to be cut back severely in winter.

Cleveland sage (Salvia clevelandii): There are many salvias that attract butterflies, but I particularly recommend this California native, which puts out stalks of blue or purple flowers in round clusters along a sturdy silver stem.

Milkweed (Asclepias): Look for one of several species of native milkweed or the ornamental A. tuberosa, also known as "butterfly weed." The small, star-like flowers attract butterflies as a nectar source, and the plant may also serve as a host plant for caterpillars.

Tall verbena (Verbena bonarienses): This is one of my favorite garden plants, and I find more uses for it every year. Small clusters of purple flowers sit atop a very stiff stalk that can reach over 6 feet tall. The flowers attract butterflies and they hold up well in flower arrangements. They re-seed and are ridiculously easy to propagate -- just bury a section of stem in the soil and water. They'll even act as a support for floppy plants or climbing vines.

Jupiter's beard (Centranthus ruber): Another plant that's so easy it's practically a weed. Lush clusters of dark pink, light pink, lavender, or white flowers attract butterflies and bees, and the plant re-seeds like crazy. It tends to bloom earlier in the year, so I plant it with fall-blooming asters to keep the butterfly buffet going late into the season.

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July Garden Checklist

Watch citrus trees for signs of nutritional deficiency. Yellow leaves with green veins could indicate a need for iron. An organic citrus fertilizer, watered in deeply, will benefit all citrus trees this time of year.
Trees getting taller than you expected? Call an arborist and have the tree looked at now, while it is in its full glory; then schedule a time for pruning in fall. The practice of topping a tree is frowned upon -- it is ultimately unhealthy for the tree -- but a good arborist will suggest ways to thin selected branches and reduce the height or girth of the tree canopy.
Water at the root zone to prevent evaporation. In particular, avoid wetting the leaves of vegetables like tomatoes, cucumber and squash, which are vulnerable to powdery mildew.
It's an election year, and what does that mean? Time to divide the irises. That's right, they need division every four years, and dividing them in election years is the perfect way to remember. All that digging and snapping apart of rhizomes may also be the perfect way to work out any frustrations you might feel over the current political situation. Just cut off the healthy rhizomes with leaves attached, throw away the center part that is not producing leaves, and re-plant or distribute to your friends and neighbors.

garden-related announcements and news to Amy Stewart.