Bringing Nature Home: How You Can Sustain Wildlife with Native Plants

by Douglas W. Tallamy

poison ivy, ferns, and tulip trees are among the plants that few extant insect species have the ability to eat, while oaks, willows, and cherries are at the other end of the spectrum, hosting over 1400 species among them.

In a study in Illinois, John Lill and Robert Marquis (2003) found that a single white oak tree can provide food and shelter for as many as 22 species of tiny leaf-tying and leaf-folding caterpillars, insects most people never notice on their walks in the woods. When all of the other lepidopterans (moths and butterflies), heteropterans (true bugs), homopterans (aphids, plant hoppers, and scales), thysanopterans (thrips), orthopterans (katydids, grasshoppers, and crickets), phasmids (walkingsticks), coleopterans (beetles), and herbivorous hymenopterans (sawflies) that develop on white oaks are considered as well, you can appreciate how important this one plant species is to the maintenance of biodiversity.

Hickories host many beautiful moths and butterflies. The most spectacular is the hickory horned devil, the larva of Citheronia regalis, the royal walnut moth. A full-grown larva often exceeds 12 centimeters (nearly 5 inches) in length and sports 10 large horns just behind the head. Though formidable looking, the caterpillar is harmless. It is most often encountered when it leaves its host and wanders about in search of a pupation site that it excavates in an underground chamber. The moth that emerges the following summer, the royal walnut moth, is one of the largest and most beautiful Lepidoptera in North America.

It is declining throughout its range and is already extinct in New England.

Like sailors to a siren, moths are drawn to lights at night where they stay until the light is extinguished. Unfortunately, they usually meet an untimely end from hungry bats long before that happens. If they are not killed directly, they spend so much energy circling lights that they soon die of exhaustion. The preponderance of lights where there used to be forest is taking a heavy toll on these wonderful animals throughout their range. Royal walnut moths have already disappeared entirely from New England.

A plea: switch off unnecessary lights when you retire at night!

One species found on hawthorn illustrates the lengths to which some caterpillars will go to hide from birds. The blinded sphinx (Paonias excaecatus), snips the remains of each leaf as it eats it from the tree, thereby removing one of the primary cues birds use to locate caterpillars among the foliage.

Knowledge generates interest, and interest generates compassion. My master’s experience taught me that if I invested some effort in understanding nature and its various components, I would no longer feel compelled to squash it as soon as it inconvenienced me.

Stag beetles are declining throughout their range because they require large dead trees from mature forests to complete their larval development. Our fragmented young woodlots often do not contain trees that are large enough or dead enough to support populations of these impressive beetles.

If we want berries in our yards, why not plant arrowwood (Viburnum dentatum), elderberry (Sambucus canadensis), alternate-leaf dogwood (Cornus alternifolia), Virginia creeper (Parthenocissus quinquefolia), spicebush (Lindera benzoin), red or black chokeberry (Aronia species), winterberry (Ilex verticillata), various native hawthorns (Crataegus species), or red cedar (Juniperus virginiana)? What do we think the birds were eating before we took it upon ourselves to plant what they “need”?

Exactly! Mother nature has always known what's best for them.

Habitat destruction as a result of anthropogenic changes is a huge problem everywhere for life on earth. That is precisely why we can no longer rely on natural areas alone to provide food and shelter for biodiversity. Instead, we must restore native plants to the areas that we have taken for our own use so that other species can live along with us in these spaces. We can start by restoring native plants to our gardens. This is a manageable task for both suburban and city dwellers, with tangible results in a few short seasons as individual gardens begin to attract the birds and the insects that will sustain them. Just imagine the restored landscape that could result from everyone’s cumulative efforts!

If we humans are capable of turning hundreds of millions of acres of rainforest into depleted grasslands, and extirpating millions of buffalo from the plains, and billions of passenger pigeons from the skies and cod from the North Atlantic, we are also capable of returning natives to our gardens.

we humans have disrupted natural habitats in so many ways and in so many places that the future of our nation’s biodiversity is dim unless we start to share the places in which we live—our cities and, to an even greater extent, our suburbs—with the plants and animals that evolved there.

If we continue to landscape predominantly with alien plants that are toxic to insects—the most important herbivores in our suburban ecosystem in terms of passing energy from plants to other animals—we may witness extinction on a scale that exceeds what occurred when a meteor struck the Yucatan peninsula at the end of the Cretaceous period. If instead we use plants that evolved with our local animal communities as the foundation of our landscapes, we may be able to save much of our biodiversity from extinction. In essence, we will for the first time coexist with nature rather than compete with her.

The costs of increasing the percentage and biomass of natives in our suburban landscapes are small, and the benefits are immense. Increasing the percentage of natives in suburbia is a grassroots solution to the extinction crisis. To succeed, we do not need to invoke governmental action; we do not need to purchase large tracts of pristine habitat that no longer exist; we do not need to limit ourselves to sending money to national and international conservation organizations and hoping it will be used productively. Our success is up to each one of us individually. We can each make a measurable difference almost immediately by planting a native nearby. As gardeners and stewards of our land, we have never been so empowered—and the ecological stakes have never been so high.