A butterfly house is a decorative, often tall and narrow, wooden structure featuring vertical slits instead of a central entrance hole. The design is marketed as a safe haven for adult butterflies, particularly overwintering species, offering shelter from weather and predators. The narrow openings are intended to allow butterflies inside while keeping out larger animals.
Optimal Location and Setup
Mount the structure on a sturdy post, fence, or tree at a height of about four to six feet off the ground, which is roughly eye-level for an average adult. This elevation helps keep the house out of the reach of ground-level predators while allowing butterflies easy access from surrounding vegetation.
Select a location that is sunny for a significant portion of the day, as butterflies are cold-blooded and attracted to warmth. Place the house in a spot that receives morning sun and is protected from prevailing winds. Positioning the house near nectar-rich flowering plants, such as milkweed or coneflowers, will encourage butterflies to visit the area.
Preparing the Interior for Use
The interior should not be left as an empty box. Since butterflies prefer to cling to rough surfaces, fill the inner space with materials that mimic natural crevices. Place small, loose twigs, strips of untreated bark, or straw vertically inside the house, providing surfaces for a butterfly to perch or hide.
Some gardeners try to tempt butterflies inside by including a small food source, such as overripe fruit or a sponge soaked in a simple sugar water solution. If using food, check the house regularly to ensure the material does not attract ants, mold, or wasps, which could make the shelter dangerous. Regularly replacing any food or damp materials inside the box is necessary to maintain a clean environment.
Understanding the Reality of Butterfly Shelters
Despite careful placement and preparation, adult butterflies rarely enter or utilize artificial wooden houses. When seeking protection, butterflies overwhelmingly prefer natural shelter options already present in the landscape. This includes the dense canopy of shrubs, the sheltered underside of large leaves, rock piles, or the rough fissures of tree bark.
Most butterfly species in temperate climates do not survive the winter as adults, instead overwintering as eggs, larvae, or pupae. The few species that do overwinter as adults, such as Mourning Cloaks or Question Marks, typically find shelter in natural wood piles or hollow trees. When the artificial houses are used, they are often occupied by non-target species like wasps, spiders, or cluster flies, which find the dark, dry space appealing. The most practical function of a butterfly house, therefore, is as an attractive garden accent that reminds the owner to plant plenty of host and nectar plants nearby.