INSECTS and GARDENS

by Eric Grissell
345 pages; Timber Press, Oregon; ISBN: 0881925047; (November 2001)

Reviewed by Marsha Salett, Editor, Conservation Perspectives

In October, I decided that it would be a good idea to bring the geraniums indoors so that they would survive our cold New England winter and brighten up the sunroom. As the trees shed their leaves, the wildflowers went to seed, and the field went dormant, the bright greenery of the geraniums was, indeed, a cheerful and almost tropical sight -- for a couple of weeks. At first I noticed a few holes in some of the leaves. Then, seemingly overnight, half of the plants were defoliated, the planters were ringed with piles of black frass, and green caterpillars in various instars were crawling on the plants and the floor. “Great” the naturalist-me exclaimed, “I can just close the door to the sunroom, continue watering what’s left of the geraniums, and, eventually, get a roomful butterflies or moths fluttering about.”

The words were barely out of my mouth, when the gardener-and-homeowner-me said, “Are you crazy? This is gross and disgusting! I want these plants and creatures out of my house now.” I lugged the planters outdoors, planning to bare-root the geraniums and overwinter them in the barn. The only reason I didn’t spray those caterpillars into oblivion was that I had no pesticides in the house or garage.

Insects and Gardens is for people like me – people who think that gardening is all about plants. Grissell is quick to point out the narrowness of this point of view: “…gardeners need to know a little about all insects in their gardens if they are to understand how a garden functions properly, naturalistically, because insects, like the soil, are an essential part of a garden’s structure.” The book unabashedly champions the insects in our gardens; you won’t find a planting plan anywhere in the book. You won’t even find a list of plants that will attract butterflies. What you will find is a fascinating primer on insects, their development and their ecological interactions not in the wild, but in our gardens. The photographs by Carll Goodpasture are spectacular.

One of the strengths of Insects and Gardens is the step-wise progression from basic information -- what is (and is not) an insect – to discussions of biological interactions and biodiversity to philosophical debate about what constitutes a natural community and what is the gardener’s role in the garden. Grissell assumes no prior knowledge of insects on the part of his readers, but has the ability to present his material with intelligence and simplicity. Clearly, concisely, and with a good deal of humor, he debunks the yuckiness of bugs. The tone is informal and conversational, but the humor can be spotty, ranging from irreverent and witty to sophomoric and cutesy. Nonetheless, it is obvious that Grissell knows, respects, and really likes insects.

The book is divided into three sections. The first part, “Lives of the Insects,” consists of four chapters about general insect development and behavior. Chapter 2, “Orders in the Garden,” is so good that it almost turned me into an insect aficionado. Grissell provides a brief natural history of each common insect order as it directly relates it to the garden, including its “garden habits.” By putting insects in their proper perspective in the garden, Grissell succeeds in deflating the knee-jerk reaction among us to look at an insect and see only a destructive pest.

Later on in part 2, Grissell confronts the notion of pests:

“The concept of pest is entirely a human notion. There are no pests in nature.
For humans, pests get to be pests when they teeter out of balance with their
environment and do things we don’t want them to do. Insect pests are the
garden’s flying weeds….The question becomes one of tolerance and how
much of it you should have.”

What does Grissell think is the best defense for insect pests? Surely, it is not pesticides, because “when we haul out the pesticides we not only must face the battle, we usually end up prolonging the war we mean to end.” The message of Insects and Gardens is to think in terms of diversity – to plant gardens with a wide variety of plants that will attract a wide variety of animals, insects included, and “to adapt ourselves and our gardens to work within the principles of nature, rather than against them.”

Part two, “The Ecology of Gardening” sets up the diversity message, first by focusing on insect-insect and insect-plant interactions, then by broadening to ecosystems. The garden as ecosystem may be a novel idea to some gardeners, but Grissell presents a convincing argument that general principles of ecology – “biological diversity increases biological complexity which increases biological stability (balance)” – applies to our gardens as well as to other ecosystems. And in our gardens, insects are essential to maintain stability and equilibrium; the greater the diversity of plants and insects, the healthier the garden. Here’s his take on a typical garden:

“Now consider your own garden. How close to a monoculture is it? For one thing,
you have a lawn that is essentially a dead, flat space. It is a monoculture in the
sense that it has scarcely any variety (and dandelions don’t count for much), and it
is drastically disturbed on a routine basis. What could live there? Then there is the
rose garden. Talk about a chemically dependent monoculture! You’ve got a dozen
insect problems, half a dozen fungus problems, mite problems, bacterial problems,
and the sorts of problems we gardeners do not talk about in polite society. The
vegetable garden is likely to be a pristine, hoed, rowed, barren sort of place. The
annuals, hybridized for looks and no nectar or pollen, have scant appeal to any
living, nonhuman being….Perennials might be a source of domestic bliss for a few
bugs now and again if they weren’t deadheaded, cleaned up every few weeks, and
scraped off the earth before winter sets in. The shrubs might offer some free
housing units for a few odd insects, but generally there are scarcely more than three
yews and a juniper in any given garden.

“If you looked at your own garden from the point of view of where organisms
might live…would your picture be as bleak as the one I’ve just drawn?….”

In part 3, Grissell discusses how to create greater diversity in the garden by increasing plant structure, temporal structure, and garden habitat structure, and offers good, practical suggestions. One advantage of having a diverse, ecologically-balanced garden chock full of many insect species, he claims, is that the gardener won’t have to work as hard – nature will do some of the work for us – and that with more natural controls available, we will be less dependent on artificial controls. Predators, for example, will keep pests in check – which reminds me of my geraniums and their caterpillars.

Lest you think that Grissell is about to lead us down some Utopian garden path, let me remind you that he is a gardener as well as an entomologist, and is a realist in dealing with both subjects. He pulls no punches about some of the more “romantic” notions of gardening. Here’s Grissell’s take on butterfly hibernation boxes:

“As with all fads, there is a tendency for the commercially greedy to prey on
our hopes of enticing butterflies into the garden. The notion of building – or
even worse, buying – butterfly houses…and placing them in the garden is founded
upon the caring attitudes of the gardening set. Pay it no mind. Hibernation boxes
are utter nonsense, in fact, they seem almost to be deadly. In a study undertaken at
Penn State University, forty butterfly boxes were placed along woodland trails
where overwintering butterflies were commonly seen. Over a year’s period, not a
single box held a butterfly. More than half the boxes held spiders, however, so the
boxes could better be thought of as butterfly coffins.”

As a realist, Grissell admits that most gardeners, himself included on occasion, just don’t like insects: “…the things that trouble most gardeners about insects fall into two categories: first, that a bug is going to do some imaginable harm to the gardener; second, that a bug is going to do inestimable harm to the garden.” The last couple of chapters of Insects and Gardens offer tips on how to appreciate insects that range from keeping them as pets to cooking and eating them.

The best way to appreciate insects, according to Grissell, is to welcome them into the garden. Every gardener has a unique vision of and relationship to his/her garden, but tthe realistic gardener learns to adapt to nature, to apply ecological principles to the artificial ecosystem of a garden, and above all, to remember that natural gardening involves more than plants. So if you are interested in natural gardening, read the books that focus on plants and plant communities such as Sara Stein’s classics, Noah’s Garden: Restoring the Ecology of our Own Back Yards and Planting Noah’s Garden, but put Insects and Gardens on your reading list, too.