Growing a wildlife-friendly garden

Growing a wildlife-friendly garden

If we want butterflies in our gardens, we need both flowers and caterpillar food plants. — Photo by Susan Safford

“Weed-free” and “orderly” are unlikely to describe a garden where non-human members of creation safely exist and thrive. Pro-wildlife words include “cover,” “food,” “water,” and “nesting.”

With the decrease in habitat land, where wildlife may freely live, gardens have become default refuges and home to many animals. Being willing to give up a measure of control helps when gardening for biodiversity.

A useful viewpoint for wildlife-friendly gardens is the concept of the food chain or web, the trophic level. “What eats what,” or the Facts of Life. The Wikipedia definition: “The trophic level of an organism is the position it occupies in a food chain. A food chain represents a succession of organisms that eat another organism and are, in turn, eaten themselves. Food chains start at trophic level 1 with primary producers such as plants, move to herbivores at level 2, predators at level 3 and typically finish with carnivores or apex predators at level 4 or 5.”

Say you want a butterfly garden and buy a butterfly bush (Buddleia). It is not too long before the realization dawns that to have butterflies, one must first have had caterpillars. To have the next generation of caterpillars one must have had food plants, and it is a fact that very many butterflies’ caterpillars are dependent on specific food-plants*, while only the adults, the butterflies, sip from the nectar-rich buddleia.

Think Monarch butterflies and immediately milkweed comes to mind. Most first-graders can tell you that the caterpillars require members of the milkweed family to grow and pupate into butterflies. As a common weed, milkweed is usually unwelcome in ornamental landscapes. Likewise, many of the other food plants indispensable for butterflies’ caterpillars are often thought of as weedy or ratty. Change that thinking!

Say you want to create a bird-friendly garden. Fruiting plants provide adult birds with carbohydrates and energy for many months of the year and help them to survive the winter. However, the next generation, the baby birds, cannot be reared on berries. They require dietary protein and fats from insect life, the “eeek!” stuff: spiders, caterpillars, moths, flies, earthworms, mosquitoes, slugs, and grubs. Change that thinking! The eeek stuff is actually indispensable to birds, and therefore to birdlovers.

However, there is far more to life than just what we can see and admire. The web of creation that supports all of us is teeming and invisible, lots of trophic level 1: myriad bacteria, virus, and microscopic animals – both predator and prey – in soil, plants, and in us. The wildlife-friendly garden is rich in life-forms, from the ground up.

By now I hope you see where I am going with this. If we wish to support the glamorous species, the creatures we love to observe, we must also support the unglamorous ones, upon whom the former depend. The gardener who wishes to create a wildlife-friendly habitat will do well to give up certain customs and fixed ideas about landscape maintenance. Many of these, specifically lawn-care and garden chemicals, are overly concerned with the killing of things and the artificial control of nature.

If we want birds, we need insects, berries, and prey (rabbits, voles). If we want fruit, we need pollinators. If we want butterflies, we need both flowers and caterpillar food plants. Some of these are low on the “useful” scale, but the first and second trophic levels are nonetheless indispensable to the creatures themselves.

Specifics

Water is a magnet for life-forms of all sorts. Humans enjoy it in their landscapes. So do vertebrates and invertebrates and it is indispensable to terrestrial life. Even a small, manmade pool or pond may support a population of fish and amphibians and the insect life to sustain them and many birds. Expect nocturnal frog noise and visits from raccoons and other mammals, and daytime visits from osprey. Birdbaths are greatly appreciated and utilized by birds, especially if fitted with heaters in cold weather. Site them and birdfeeders with enough cover to shield them from hawks.

Cover means the kind of plantings and their maintenance that allow for privacy and seclusion, especially for burrows and the rearing of young. Strictly pruned shrubberies and hedges provide less cover than the wilderness of growth that characterizes untidy ruderal areas and briar patches, yet they nonetheless manage to support many nesting birds. Keep this in mind when pruning hedges.

The array of flowering plants that in turn produce berries and fruits benefit not only the animals but also us humans as well, at least theoretically. (It is astonishing what a “thieving” pair of catbirds can consume.) Viburnums, hollies, crabapples, aronias, brambles, blueberries, beachplum, and shadbush are some of the nursery-grown stock available that ably fulfill the wildlife requirement.

Clovers are among the best bee-forage. White clover keeps lawns green during the dog days. It supplies nitrogen fixed from the atmosphere, as well as having a tough root system and being a great erosion controller. Red clover, a plant that grows about 12 to 16 inches tall, is bee-forage for bumblebees. These are rapidly becoming one of the important fallback pollinators, with the loss of wild honeybee colonies, but are also under assault themselves due to lack of their preferred foods and pesticide residues.

Other relevant support for pollinators are plants that flower during the shoulder seasons: early in spring, such as swamp maple and winter- and spring-blooming heathers; and late in autumn, such as native witch hazel (Hamamelis virginiana), asters, and late goldenrod, and garden plants that may be kept in bloom.

*Comprehensive guide to caterpillars and their food plants: “Caterpillars of Eastern North America” by David L. Wagner (Princeton U Press).

Abigail Higgins of West Tisbury is The Times’ Garden Notes columnist.