Dragonfly Gardening

My dad told all kinds of fantastical stories when I was a kid, and I believed all of them. To this day, I can’t drive past a “Watch For Falling Rock” sign without thinking about the Native American hero named Falling Rock, who disappeared in the desert and was never seen again. If I had kids, I would tell them stories about dragonflies, something about how a magic spell of some sort turned big-eyed, prehistoric beasts into delicate winged creatures that really like water.

Dragonfly
Credit: iStock

I’m not sure exactly when dragonflies started inhabiting our gardens. But these days, they are as nearly as ubiquitous as the butterflies and bees used to be just a handful of years ago. Perched on plants or flitting around from one place to another, the brightly colored creatures are as unreal as seahorses and endlessly interesting to watch. They’re also beneficial carnivores, capable of eating hundreds of mosquitos in a single day.

Attracting dragonflies to your yard is easier than you might think. The most crucial thing to provide is a water source, and even the simplest water feature will do. It’s also important to include a diverse mix of plants, trees and shrubs that can provide cover; offer places to mate and lay eggs; and draw in insects that hungry dragonflies can munch on. But before I go into more detail on how to invite them, here is a bit more that you might not know about these interesting creatures.

What Are Dragonflies?

Dragonflies really do have prehistoric roots. More than 300 million years ago, they were among the first winged insects to evolve. While today’s dragonflies have wingspans that range from about 2 to 5 inches, some dragonfly fossils have been found to have wingspans of more than two feet. That is frightening enough. But the thought becomes absolutely terrifying when you consider that the aquatic insects belong to the insect order Odonata, which is Greek for “toothed one,” referring to dragonflies’ serrated teeth. When they eat, dragonflies most often snatch flying insects in midair, tear them into bits, smush the bits into a ball and chow down.

Look closely and you’ll notice that dragonflies can look quite different from one another. That’s because the insect order Odonata also includes damselflies. Generally smaller than dragonflies, damselflies have slim bodies and eyes that are separated and somewhat protruding rather than flat and centered on their heads.

Damselflies hold their wings above their backs like butterflies do. Credit: iStock

Dragonfly
Credit: iStock

It’s easiest to tell the two relatives apart by looking at their wings when they’re resting on something, which damselflies do more often than dragonflies. Dragonflies rest with their wings flat and parallel to the ground while damselflies hold their wings pressed together over their backs, like a butterfly. An estimated 5,000 to 6,000 dragonfly and damselfly species have been identified worldwide, and about 140 species can be found in Minnesota. Go here to learn more and see photos of some our state’s dragonflies and damselflies. To hone your dragonfly identification skills, check out Stokes Beginner’s Guide to Dragonflies by Blair Nikula, Jackie Sones and Donald and Lillian Stokes.

 Ponds

Most dragonflies and damselflies need water throughout their entire lifecycle. Every species has its own requirements for things like water quality and the types of aquatic vegetation on which they prefer to lay their eggs—though they also lay eggs in the water. In their larval stages, when they are known as nymphs, the insects spend months, sometimes years, living underwater before emerging as adults.

Adding a pond to your landscape is sure to bring on the dragonflies. If you have the space and resources to do that, choose a spot that gets at least five hours of full sun in an area that’s somewhat sheltered from winds, especially from the north. If possible, create a pond with varied depths so there are shallow areas near the edges and a depth of at least two feet in the center. Larvae will be safer from predators like raccoons in the deeper parts of the pond. Because fish feed on nymphs and eggs, it’s best not to include them in ponds where you’d like to encourage dragonflies to breed.

Stock the pond with water-loving plants, including submerged plants for females to lay eggs on and tall emergent plants for nymphs to climb up when they’re ready to slough off their last larval exoskeleton and transform into flying adults. Adults will also use emergent plants when they stop to perch and scan for potential mates or food sources. There are several submerged plants (also called oxygenator plants) to choose from, but a few good options are: anacharis (Egeria densa), fanwort (Cabomba canadensis), hornwort (Ceratophyllum demersum) and wild celery (Vallisneria sp.).

Horsetail
Credit: Mike Hoium

A few emergent plants to consider are: corkscrew rush (Juncus effuses), dwarf horsetail (Equisetum scirpoides),dwarf papyrus (Cyperus isocladus), blue flag iris (Iris versicolor) and parrot’s feather (Myriophyllum aquatic).

More Water Ideas

Don’t have room for or want a pond? How about a small rain garden or bog garden? Or maybe a water container garden made from a half whiskey barrel, galvanized tub or anything else that’s handy and can hold water will work well. Use the same plants mentioned above to create your container water garden, which should be located in a sunny spot. For detailed instructions on creating container water gardens, see my article on the subject in the May/June 2013 issue of Northern Gardener.

If all of that sounds like too much work, take the easy route and just add a water feature like a simple fountain. We created a few small fountains for our yard using inexpensive pond pump kits that we bought on sale at a local big-box store combined with a galvanized tub or livestock troughs. Be aware that pond kits don’t always come with filtration systems that are adequate enough to handle outdoor debris. So you may want to do what we did and buy an additional filter box that will filter the water before it enters the pump.

A simple water feature in our backyard.

Place your container where you want it, put the pump in the bottom of the container and use a rock or brick to hold the cord in place. Next, drape the cord over the edge of the container and use another rock to secure it on the ground before directing it toward a power source. Fill the tub with water, flip the switch and your gurgling fountain becomes a magnet for dragonflies and damselflies. Adding plants will hasten their appearance, but it isn’t necessary. Basically, if you have a water feature, they will come.

Plants for Every Purpose

The plants that you choose for your landscape are nearly as important as the water you provide. Dragons and damsels will use ornamental grasses, shrubs and trees planted within a few feet of a water source as perching sites and to help them hide from predators like birds and spiders. Flat rocks placed around the edge of a pond, water container or fountain will become places to rest and bask in the sun. And although midges and mosquitos make up the bulk of their diet, you’ll see more of these meat-eating beauties if you plant flowering perennials that entice beetles, wasps, moths and other small flying insects that become their prey. (Yes that does include some bees and butterflies.)

Bee balm (Monarda didyma), black-eyed Susan (Rudbeckia hirta), black snakeroot (Actea racemosa), blanket flower (Gaillardia), cardinal flower (Lobelia cardinalis), catmint (Nepeta), coneflower (Echinacea), Culver’s root (Veronicastrum virginicum), golden Alexander (Zizia aurea), goldenrod (Solidago canadensis), Helenium, Joe-pye weed (Eupatorium fistulosum), Liatris, Phlox, Russian sage (Perovskia atriplicifolia), speedwell (Veronica), Salvia, swamp milkweed (Asclepias incarnate) and yarrow (Achillea filipendula) are all great choices.

Ensuring A Safe Haven

Like bees and butterflies, dragonfly and damselfly populations around the world are in decline in part due to pesticides. Studies have shown that the widely used neonicotinoid pesticide, imidacloprid, is particularly toxic to the aquatic insects, as well as other water-dwelling species. So if you want to attract dragons and damsels, do your best to steer clear of pesticides and other chemicals that may be harmful. And if you’ve got one of those bug zapper things to help control mosquitos, put it away because it will zap the dragonflies too. Don’t worry. In a very short time, those hungry little carnivores will thank you by keeping mosquitos in check all on their own.

A version of this article appeared in the 2014 September/October issue of Northern Gardener magazine.