Fall Planting is just ahead, a great time of the year for additions to your native plant garden that welcome and support butterflies. They need your help. After last winter, with the severe lack of rain, the numbers of butterflies have dropped dramatically. Fewer butterfly eggs have hatched and the larva (or caterpillars) that did emerge found less food of inferior quality. A lot of wildflowers never made it to bloom, which robbed adult butterflies of delicious nectar. The females, in turn, laid fewer eggs. The yearly count in June showed how shocking it was. For instance, last year’s count at Rancho Mission Viejo Land Conservancy found more than500 Common (California) Ringlets. This year, fewer than 100 were counted. The Ringlet is a grassland butterfly that lays its eggs on native bunch grasses. The caterpillars that hatch enjoy dining on the delectable blades of grass. When the grassland dries up too early due to lack of winter moisture, there is not enough food for the caterpillars. This is all part of a natural cycle, and the butterflies will recover with winters of rain. Won’t they? Or will we reach a critical mass with the loss of habitat? Let’s consider how a native plant garden can help.
As described earlier, butterflies use plants in two ways. A female adult butterfly usually lays her eggs on select plants, known as food or larval host plants. These are the plants that the caterpillars consume. Adult butterflies need plants that provide nectar. Some plants,like some of the buckwheats, are both larval host and nectar plants. Our native plant sale this fall is a great place to obtain plants that are used by butterflies.
The layout of a butterfly garden is important too. Larval host trees and shrubs, along the perimeter of the garden, will entice various butterflies to take a chance and dance in the sunlight. Trees such as oaks, aspen, willow, and sycamore not only provide welcomed relief from the blazing sun and harsh drying winds, but also an opportunity for females to propagate the next generation. Some shrubs can become as big as a small tree offering a place for under story plants to nestle. These edges between trees, shrubs, and under story plants provide a smorgasbord of vegetation, not only working as larval food plants, but also offering a variety of habitat types. Trees give the garden vertical layering, producing shady microclimates. Shrubs can diversify the garden horizontally and protect the smaller shade-loving plants. Depending on their orientation shrubs can produce different sun exposures.
Vines like the native honeysuckle (Lonicera spp) and the spectacular San Miguel Coral Vine can also do double duty. While the “wandering ways” of vines offer cover for wildlife, the Variable Checkerspot caterpillars also find the honeysuckle delectable. The Coral Vine would tempt the Common Hairstreak to while away part of the day nectaring and laying eggs in the protection of this beautiful vine. Many times I have watched a butterfly maneuver in and around the vines, searching for a shady spot to lay her eggs, sometimes almost disappearing from view among the foliage, only to reappear again when the job is done. Many butterflies will select the more sheltered and shady parts of the plant on which to lay their eggs. This care protects the eggs from desiccation.
Many species of butterflies can be found in riparian communities gliding about the treetops and coursing along the waterways. They stop to sip water and other nutrients from the moist mud and sand. The boulders and rocks in and along the stream, when warmed by the sun, turn butterflies into sun worshippers. This same environment can be reproduced in your garden. When the planting is done, and the stage is set, place your garden bench in a cool shaded area, so you can relax and enjoy the show.
—by Sandra Huwe, Butterfly Gardener