Butterfly populations in California are declining, according to a study conducted at the University of Nevada. The culprits: Climate change and loss of butterfly habitat due to building, agriculture and logging. CBSnews.com cites at least 140 million acres of Monarch butterfly habit replaced by development the U.S. over the past 16 years. The good news is some varieties, such as the Monarch butterfly, saw a population uptick over the past year during Spring migration in April 2011.
Not satisfied with color and entertainment in the garden? Butterflies aim to please. Even if they're not super-pollinators like bees, they skip and flit and perform their fair share of garden pollinating. Plus, in the larval stage, caterpillars are a food source for birds and small mammals, and some offer biological controls of pests such as aphids.
Caterpillars who escape the food chain might do so thanks to the leafy greens they eat. Mildly-toxic milkweed plants are the salad bar of the Monarch caterpillar. Birds who eat this toxin-sated treat will vomit. Because they are not bird-brains after all, these feathered missiles have learned not to ingest the Monarch.
Butterflies in general need a few specifics
They are diurnal, or daytime-active. Cousin moths, also of the order Lepidoptera, are nocturnal. Both are cold-blooded and rely on warm climate to survive. Butterflies are most active when the temps range from 80 to 100 degrees Fahrenheit.
So, during the hottest parts of the day they will take shelter in cool spots, between rocks, in woody nooks, under shrub leaves, and will sleep in the same types of places at night or during inclement weather.
Nectar is their main food source, but rotting fruit, ooze from trees and fresh dung are delicious treats, too.
They also need mineral rich water, and a place to perch while feeding, as their taste receptors are in their feet. Butterflies live from several days to 18 months. Life cycles occur year round, with the most activity during warm seasons.
With these clues in mind, invite butterflies to your garden. Even the smallest patio can offer butterfly-sustaining plants. Flowering, nectar-producers are important to the adult butterflies, especially in reds and yellows. Specific host plants are necessary to the egg-laying adult and as a ready food supply to the hatched caterpillar with its limited mobility.
TIP: Don't Plant Invasives
Many caterpillars feed on grass plants and seed material. Some grasses are so aggressive they overtake other plants in their path, threatening natives and beneficial non-native plants. Take care never to plant Pampas Grass (Cortaderia jubata or Cortaderia selloana) or Green Fountain Grass (Pennisetum setaceum) anywhere, no matter what the discount plant nursery tells you.
Instead, try California fescue (Festua californica), Red Fescue (Festuca rubra) or Idaho Fescue (Festuca idahoensis). For more information on noxious plants visit the California Invasive Plant Council website.
Now let's get down to brass tacks. Here are a few plants - California natives, no less - that butterflies will simply flit over.
Narrowleaf Milkweed: Necessary food source for Monarch caterpillars. White sap causes skin itch so wear long sleeves when planting. Three foot tall stems, with long, narrow leaves.
Erigeron Seaside Daisy: Seaside Daisy is a compact plant, with moderate water requirements, used as an understory. Provides food and nectar.
Island Mallow provides larva food and a is great big plant for a sunny bed. Grows 10-12 feet tall.
California Native Thistles, grows 6 to 8’ tall, provides food and nectar. Needs room to spread.
California Buckwheat, herbaceous shrub, grows to three feet tall, white flowers, drought tolerant.
Scarlet Monkeyflower: Shrub grows to three feet high by two feet wide. Favored by hummingbirds, and butterfly larva of the Common Checkerspot and Buckeye butterfly.
Bush Sunflower or California Encelia, sprawling perennial shrub, with 2” yellow flowers. Food plant for caterpillars.
Penstemon Scarlet Bugler, nectar and food. Beautiful tubular flower blooms continually throughout the summer. Needs fast draining soil, moderate water.
Ceanothus species, for nectar and caterpillar food. Many varieties are beloved by butterflies and caterpillars.