Observing fireflies, also known as lightning bugs or glowworms, while camping or on a midnight stroll is a magical experience, evoking in many a sense of wonder and nostalgia. Whether you’re interested in firefly biology or ecology, are interested in bringing fireflies to your yard, or simply want to enjoy their mesmerizing displays, this guide will have the answers you need!
Firstly, what are fireflies? Contrary to their common names, fireflies are not “flies” or “bugs” but beetles with glowing abdomens. They can activate a bioluminescent reaction at will using an enzyme called luciferase. Different firefly species produce other colored flashes and flash in various patterns to differentiate species. This is important because they primarily use their glowing capabilities to attract mates. However, some females will attract males and promptly eat them!
Firefly larvae are highly predatory, and only adults of certain species will eat in their adult form. Others simply do not eat and die after mating and laying eggs. Interestingly, females of some species, such as those in the genus Photuris, will trick males of another species using flashing cues to trap and eat them.
Fireflies also have a place in culture. For example, fireflies in the genus Luciola are native to Asia and are thought to be dead souls in traditional Japanese culture.
1) Switchgrass (Panicum virgatum)
Switchgrass is a warm-weather perennial grass native to North America that provides shelter for fireflies. This grass can also be used to control erosion and attract other animals. There are many varieties of switchgrass, so choosing a variety compatible with your area is essential. They prefer well-drained, acidic soils with a pH between 5.5 and 6.5.
Switchgrass can be planted as a seed or propagated from established plants and should be produced when the weather is warm. Once installed, switchgrass must be managed through regular trimming or mowing. In addition to being an attractive perching spot for fireflies, switchgrass is also pest-resistant and susceptible to very few diseases.
2) Blanket flowers (Gaillardia spp.)
With their beautiful blooms, blanket flowers are an excellent addition to any garden. In addition to being a decent perching spot for fireflies, Gaillardias will attract firefly prey species like aphids. Blanket flowers should be grown in full sun but tolerate drought and various soil conditions. Usually, blanket flowers are planted as seeds or transplanted as seedlings from nursery pots. Blanket flowers can attract aphids, making a tasty treat for voracious firefly larvae.
3) Big bluestem (Andropogon gerardii)
Big bluestem is more common in wilderness areas than in yards due to its large size, which provides decent bird cover and is a food source for wildlife. These large grasses grow to heights of 6 to 8 feet (1.8 to 2.4 meters) and have a blue tint to their leaves. They are usually found in warm-weather prairies with clay and sandy soils with decent rainfall. As a result, this grass needs full sun and plenty of water. Once established, big bluestem is relatively low-maintenance if the plant grows tall. Additionally, it can be cut down early in the growing season to encourage new growth.
4) Indiangrass (Sorghastrum nutans)
Also known as yellow Indiangrass, this Sorghastrum species is another warm-weather grass with golden seed heads that give the plant its common name. Like big bluestem, Indiangrass has blue stems, but their seed heads can distinguish the two species. Growing conditions for Indiangrass are like those required by big bluestem, but Indiangrass appears to be more tolerant of soil conditions than big bluestem.
Soil pH can be between 4.8 and 9.0. They are also tolerant of adverse salinity and drought conditions. When well cared for, Indiangrass can reach heights of up to 8 feet (2.4 meters), providing plenty of ground cover and protection for fireflies and their larvae.
5) Western wheatgrass (Pascopyrum smithii)
Western wheatgrass can be found throughout the United States, especially in the western United States. Its seed heads resemble wheatgrass and have blue-green stems with distinct veins. Compared to Indiangrass and bluestem, western wheatgrass grows between 1 and 3 feet (0.3 and 1 m). Western wheatgrass can be used to control erosion due to its strong roots known as rhizomes.
This plant tolerates saline soils with a high pH and thrives here where other grass species may not. Where bluestem and Indian grass thrive in the eastern United States, western wheatgrass does best in the country’s western half. It makes a fantastic alternative to these eastern grasses where soil pH may be too alkaline or salty for eastern grasses.
6) Blue grama (Bouteloua gracilis)
If tall ornamental grasses are not your style, there are shorter alternatives like the blue grama, which only reaches between 0.75 and 2 ft (0.23 to 0.6 m). This small perennial is native to the Midwest in the United States and produces unique seed heads that hang at an upright angle and plant feathery seeds. It can be found in warm climates and desert habitats at higher elevations than other species on this list. Blue grama is known to be a low-maintenance alternative to common lawn species due to its drought tolerance and low water requirements. Additionally, the seed heads are edible when appropriately prepared.
7) Pine trees (Pinus spp.)
Pine trees are usually already present in environments where fireflies are common. Planting a new pine tree can mean waiting years to reap the benefits of growing this plant. If you are lucky enough, your firefly garden will already have several pine trees towering over it. Adult fireflies are attracted to pine trees because these trees are the perfect place to lay their eggs. Native pine tree species can also indicate environmental health, so their presence often already overlaps with the fireflies because they both indicate a healthy ecosystem.
8) Goldenrod (Solidago altissima)
Moving on from grasses and trees, several flower species are also associated with fireflies. Goldenrods, for example, are very common throughout North America and provide food for countless pollinators. They make excellent ground cover and can add a pop of color to a grassy landscape in addition to added biodiversity. Other organisms, like aphids, are attracted to goldenrods and can become food for firefly larvae.
These flowers grow best in full sun and require a soil pH of 6 to 7. Once established, they will require little care but may need protection in colder climates and annual trimming to encourage seasonal regrowth.
9) Morning glory (Ipomoea spp.)
Morning glories are one of the easiest vining plants to grow. They grow so well that many species are considered invasive in North America. As a result, it is essential to take care of any morning glories introduced to the garden and prevent them from escaping into the wild. Morning glories are perennial flowering plants that earn their name from their beautiful blooms, which open during the morning and close at night. However, some species, like the moonflower (Ipomoea alba), only bloom at night.
Morning glories are a great way to add diversity to a firefly garden and will climb on existing structures, covering them in entire green leaves and beautiful flowers. Morning glories are not picky about where they grow, but they should have full sun and a place to climb.
10) Purple coneflower (Echinacea purpurea)
Regarding wildflowers, the purple coneflower is not the only species that will attract fireflies. Still, it is an example of a widespread flower species found throughout the United States that can easily improve a garden’s biodiversity. These easy-to-grow plants have simple, purple flowers that are attractive to various pollinators.
Despite their common name, purple coneflowers come in multiple colors, including pink, yellow, and red. They bloom during the summer, and blooms can last up to two months. Purple coneflowers grow best in zones 3 to 9 and require full sun, water, and well-draining soil. If you forget to water them, they are very forgiving due to their drought-tolerant nature.
Extra Tips to Attract Fireflies to your Garden
The best way to attract fireflies to your yard or garden is to craft a naturalistic and diverse landscape that mimics the firefly’s natural habitat. No single plant attracts them, as fireflies only use plants as a place to rest, mate, lay eggs, and hunt. As a result, it is essential to know what firefly species are present locally and what native plants are present in the same ecosystems that the fireflies live in. Additionally, gardeners must cater to all firefly life stages, from the egg to the predatory larvae and, finally, the adult.
It is generally recommended that gardeners plant various plants, including grasses, vines, flowering plants, and trees. Each plant type contributes to an area’s overall biodiversity, attracting fireflies and other beneficial insects like pollinators and predators. Prey species like aphids, snails, and slugs are also attracted to these areas and will provide firefly larvae with plenty of food. Additionally, some firefly larvae are aquatic so a firefly garden will benefit from a minor water feature like a small predator-free pond or an untreated fountain.
Adults will use grasses, leaf litter, and trees as places to hide, mate, and eventually lay eggs. If you are catering toward nighttime fireflies, they will need to see each other flashing at night to find a mate, so artificial lights should be turned off until late into the night.
How Do I Find Fireflies?
Fireflies are found worldwide, and there are around 2,000 different species. Most species are active during the day or night and have predatory larvae. The first step to finding fireflies is learning how to identify them. Generally, adults have dark-colored elytra and bright thoraxes with orange, red, or yellow coloration. Firefly larvae have heavily armored segments with serrated edges, usually black or brown. Some larvae sport colorful markings as well. As a side note, glowworms are firefly larvae that bioluminesce. Still, they are distinct from other firefly species in that adult females remain in their larval form while only adult males pupate into winged adults.
The best places to spot nighttime fireflies are open fields, meadows, or forest edges. Ideally, the location should be far from areas with artificial light. Timing is also essential. Depending on the species and place, fireflies are only active during a short period of the year, usually from spring to summer.
