IF YOU ARE SERIOUS about enjoying exquisite butterflies in your garden, you will need to feed their young… with your landscape plants. Some lost foliage or bloom is a small sacrifice to make in order to have such beauty grace your garden!
Adult butterflies generally sip nectar from a broad range of plants. In contrast, each type tends to use a specific plant, or closely related group of plants, upon which to lay eggs. If you are attempting to lure a particular kind of native butterfly to your garden you will need to know the preferred host plant, or larval food plant, to include in your plant palette. After the eggs hatch, tiny caterpillars (or larvae) begin munching the larval food plants. They will eat their fill until they become large enough to pupate, each forming a chrysalis from which the next generation of enchanting adults will emerge.
Don’t be concerned if a caterpillar crawls away from the host plant when it is ready to pupate, seeking a sheltered spot on another type of plant. Remember to not use chemicals around your butterfly garden, especially Bt (Bacillus thurengiensis) which is a powder often used to kill undesirable caterpillars. Not only will it kill loopers and tomato hornworms, but it will also eliminate your desirable butterfly caterpillars if it comes in contact with the plants they eat.
A wide range of plants from trees, to groundcovers, and everything in between may accommodate caterpillar development. If you like variety, mix plantings from the list of larval food plants and see what type of butterflies you attract.
Our Desert Milkweed (Asclepias subulata) is not only a nectar source for queen and monarch adults, but it also serves as caterpillar food for both. The queens will munch young tender leaves on new stem growth, as well as flower buds and blooms. Since the plant will continue to develop new buds throughout the warm season, and foliage only persists for a very short time before dropping from the plant naturally, you really aren’t losing much. Monarchs tend to become active later in the fall season. They both develop jewel-like chrysalids when pupating to change to their final form as adults.
If you are interested in attracting the gulf fritillaries that appear as though someone painted spots of silver on the undersides of their delicate orange wings, plant passion flower vines. The Mexican Passion Flower (Passiflora mexicana) and Blue Passion Flower (P. caerulea) tend to be evergreen in the low desert, whereas in extreme cold Maypop Passion Flower (P. incarnata) will drop its leaves. All species produce unique frilly lavender, purple, and white flowers of differing sizes with variable foliage. They serve as host plants for the orange, black, and white caterpillars that develop chrysalis cases that look like furled leaves. The vines will thrive in morning sun exposure, and with careful watering they can endure full-day sun through the summer.