Why would I want to invite insects into my garden? Don’t most homeowners want to get rid of the bugs? It’s true that some insects cause major problems in a landscape, chewing indiscriminately and leaving behind a trail of devastation. But don’t let a few bad guys ruin it for everyone—there are plenty of insects who can live harmoniously among our plants. Some, such as bees, more than earn their keep. And who doesn’t enjoy a garden full of butterflies?
As I planned our new garden, I realized that I could intentionally encourage the presence of butterflies, bees, and other helpful insects. I’m also interested in those who do little or no harm, but are just plain interesting. The bugs, in turn, will provide yet another food source for birds, especially those who spurn a feeder full of sunflower seeds. Plus, I’ll have plenty of subjects for my growing interest in macrophotography—right outside the back door!
Selecting plants for insects is proving an enjoyable challenge. In keeping with the rest of our landscape, the plants have to be drought-tolerant. They need to survive our zone 4 garden, at an elevation of 7,100 feet. With no mature trees, we have very little shade, although there’s space on the east side of the house for those who need a bit of coddling. And the flowers and/or foliage need to be attractive enough to earn a place in my small yard.
Butterflies are at the top of almost everyone’s “favorite insect” list, and I want plenty of variety. In general, butterflies prefer flat-topped flowers for nectar-sipping. So far, my garden includes coneflowers (left), rudbeckia, Sedum ‘Autumn Joy’, blue-mist spiraea, red and yellow yarrows, rabbitbrush, and Russian sage. Next spring I’ll add annuals such as zinnias and cosmos, plus more perennials.
Butterflies start out as hungry, hungry caterpillars. They aren’t nearly as popular at this stage! If I want the adults, however, I first have to put up with some leaf-munching. The most obvious place to start is with milkweed. Most people know monarchs require milkweed, but not every species of Asclepias will do—and some aren’t suitable for our area. This fall I intend to collect seeds from the native Showy Milkweed plants nearby. Other milkweeds are attractive to other butterfly species, so I’ve included those as well.
Parsley, lovage, fennel, and their relatives are hosts for “parsley worms,” i.e. swallowtail larvae. These plants need more water, so I’ll group them in a “damp zone” along with a few other non-xeric must-haves such as goldenrod, a veritable insect magnet.
If you want to learn more about which plants to choose here along Colorado’s Front Range, check out this interview with George Brinkmann, former garden designer for the Butterfly Pavilion in Broomfield.
Another important consideration is shelter. Does your yard provide places for bugs to survive a torrential downpour? How about a warm crevice in which to overwinter? Rocks, shrubs, trees, and mulch all provide places where an insect can hide.
Of course, if you want to have an insect-friendly yard, insecticides are definitely out. But what do you do if an insect pest moves in and tries to take over? There are approaches to insect control that don’t involve chemicals, and that would be the place to start. Keeping your garden healthy keeps destructive insects from gaining a toehold. Exclusion (screening), predatory insects, trap crops, and hand-picking are all other options. If nothing else works, limited spraying directly on the problem plant would be the last resort. But think first—is this an important plant? Are these pests going to kill it, or just make it less attractive for a while? Spraying a valuable tree in danger of dying is one thing—spraying an annual flower in late summer is another.
Welcoming insects to our yards requires a major attitude adjustment for most gardeners. I’ve been joining field trips led by a couple of entomologists, and they’re opening my eyes to the tremendous diversity and fascination of the insect world. Next time you see a bug, don’t just yell “ick!” or step on it. Get to know it—you might be glad you did!
Photos, from top: Monarch Butterfly, Green Lacewing, Common Ringlet, Coneflower (Echinacea purpurata), swallowtail larva on poison hemlock, bee, asparagus beetle?, Orange Sulphur Butterfly (aka Alfalfa Caterpillar/Butterfly).