Green Thumb: Designing a garden for butterflies, hummingbirds

Cynthia Reiners, a member of the Arizona Native Plant Society and docent at both the Tucson Botanical Gardens and the Arizona-Sonora Desert Museum will be the guest speaker at Thursday’s seminar (March 26) by the Green Valley Gardeners at 9:30 a.m. at East Center.

She wrote the following article as a preview to her Powerpoint presentation.

By Cynthia Reiners

Butterflies and hummingbirds, often called “Winged Jewels of the Garden,” are beautiful and intriguing visitors to our landscapes.

Careful plant selection and a few design details are all that is needed to attract them to a home garden. The key to success is understanding the relationship between plants and their pollinators.

Pollination

Pollination is the process of transferring pollen grains from the flower of one plant to the flower of another plant of the same species. This is how plants achieve sexual reproduction, mixing the DNA from two different individual plants to create new seeds, each with a slightly different genetic blueprint.

Being rooted in the ground, plants need external assistance to move their pollen to a distant target. Some, such as grasses and ragweed, depend on wind to disperse their pollen. Many others entice insects, birds and mammals to do the job. The beautiful flowers we humans so enjoy in our gardens are in fact the mechanism these type of plants have evolved to attract and utilize specific kinds of pollinators.

Amidst a complex landscape of competing plants, flower size, shape, color, and fragrance all signal a specific flower’s presence and availability to its pollinators. The season of the year, and time of day, that the flower blooms are also important. As an inducement for the animal to get close enough for pollen transfer, the flower may offer food, including nectar, pollen or visiting insects, or provide shelter or opportunities for mating.

Pollinators

There are some very general guidelines as to which types of flowers attract which types of pollinators, although there are always exceptions.

Hummingbirds can hover and therefore access long tubular flowers. They are attracted to pink/orange/red colors. Penstemons, Autumn sage, Chuparosa and other plants in the Anisacanthus family are good examples.

Large butterflies will also hang lightly on the edge to drink nectar from these flowers. A butterfly’s size often matches blossom size, with tiny blues frequenting the small blossoms of Dalea, Acacia or Buckwheat, while large swallowtails prefer the big blossoms of Mexican bird of paradise or Mexican sunflower.

Butterflies also use a wider spectrum of flower colors than hummingbirds. Nocturnal moths and bats do not see color, so their flowers open in the evening and are typically white and fragrant, such as Evening primrose or Saguaro.

Butterflies can be attracted to a garden by more than just flowers, however. This is related to these insects’ four stage lifecycle: egg - caterpillar-chrysalis-adult butterfly. Caterpillars typically eat the foliage of only certain types of plants. These are called larval food plants or host plants.

The most famous of these relationships is monarch and queen butterflies and milkweed plants. Including the larval host plants of butterflies common in your area will include the total number of butterflies in your garden.

There are, of course, many other kinds of pollinators. Bees, wasps, beetles, flies, ants, etc., will also come to the same flowers, and in turn attract predators such as birds and lizards. Plants are indeed that basis for a thriving community of many types of animals.

Design

Beyond plant selection and proper siting, there are some other important design elements to consider for a successful, year-round pollinator garden.

Animals of all kinds need shelter, from wind, cold, sun and predators. For example, hummingbird and butterflies need places to perch during foraging, and to roost at night. Birds need dense vegetation and appropriate materials for nests. Resident pollinators need flowers blooming throughout the year.

The best way to meet these needs is through planned diversity, of plant forms, plant families, and flower characteristics. Good landscape design principles, such as planting in groups of 3, 5 or 7, and repeating certain accent plants in multiple locations, can help this high degree of plant diversity look pleasing to the eye.

With careful plant selection and thoughtful design, your garden can be filled with the color and movement and interest of many different pollinators. Enjoy.

Please join the Green Valley Gardeners on Thursday at East Center. The seminar begins at 9:30 a.m., but come as early as 9 for coffee, socializing and “ask the Master Gardener.”