Dragonflies are highly sought after by gardeners for their predatory nature. Their presence signals a healthy aquatic ecosystem. Attracting them requires providing habitat for both the aquatic larval stage and the flying adult stage. The primary benefit is natural pest control, as adult dragonflies consume hundreds of small insects daily, including mosquitoes, flies, and gnats.
Aquatic and Emergent Plants for Larval Habitat
The dragonfly life cycle begins in the water, where the nymph spends the majority of its existence, sometimes for several years. Nymphs require underwater structure to hide from predators, such as fish, and to ambush prey. Submerged aquatic plants are foundational, providing camouflage and a source of dissolved oxygen.
Plants like hornwort and wild celery grow entirely beneath the surface, offering the dense, protective cover that dragonfly nymphs need as they develop. The complex root structures and underwater stems of these species create a safe haven where the nymphs can lurk among the sediment and leaf litter. This underwater environment supports the nymphs until they are ready for their transformation into flying adults.
The final molt requires the nymph to exit the water, making emergent plants necessary for successful metamorphosis. Emergent species are rooted underwater but feature stiff stems that rise above the surface, acting as ladders for the nymphs. Plants such as Pickerelweed, Cattails, and various Water Iris varieties provide the sturdy, vertical support necessary for this delicate process. The nymph climbs the stem, secures itself above the waterline, and splits its exoskeleton to unfurl its wings, leaving behind the shed skin, called the exuviae.
Terrestrial Plants for Adult Perching
Once dragonflies emerge as winged adults, their needs shift from aquatic shelter to aerial vantage points for hunting. Adult dragonflies are perching predators, meaning they sit and wait for insect prey to fly past before launching a swift pursuit. They require tall, sturdy terrestrial plants situated around the water feature to serve as strategic perches. These plants must provide an unobstructed view of the surrounding air space.
Ornamental grasses and robust perennial flowers offer the necessary height and vertical structure for perching. Species like Joe Pye Weed and Black-Eyed Susans are excellent choices because their firm stems and tall stature place the dragonfly high enough to spot and intercept prey. The plants should be positioned in sunny areas, as dragonflies often perch to bask and regulate their body temperature for flight.
The selection of these plants also helps attract the smaller insects that dragonflies prey upon, creating a self-sustaining hunting ground. Tall, vertical structures allow the dragonfly to conserve energy while waiting for a meal. Adult insects utilize the tips of these plants for resting, surveying their territory, and displaying mating rituals.
Essential Environmental Structure and Placement
A successful habitat for dragonflies depends less on a single plant species and more on the intentional arrangement of diverse vegetation types. The pond or water feature should incorporate varied water depths, including gently sloping shallow margins where emergent plants can thrive and deep areas that offer thermal refuge for nymphs during cold periods. A general guideline suggests that aquatic vegetation should cover approximately 50 to 70% of the surface area, with a blend of submerged, floating, and emergent plants.
Strategic placement of plants is enhanced by incorporating non-living elements such as flat, light-colored rocks or exposed logs near the water’s edge. These objects absorb solar radiation, providing warm surfaces for adult dragonflies to perch on and increase their body temperature for flight. The entire habitat should ideally be located in a spot that receives full sun, as warmth accelerates larval development and supports adult activity.
Maintaining a chemical-free environment is paramount, as the use of broad-spectrum insecticides or chemical algaecides will destroy the aquatic nymphs and eliminate the insect prey that sustains the adults. Creating a dense, multi-layered environment using the sturdy, vertical plants mentioned previously, along with small shrubs, helps provide shelter from strong winds. This combination of diverse aquatic structure, terrestrial height, and chemical avoidance ensures a supportive environment for all stages of the dragonfly life cycle.