Flies around houseplants can be an annoyance, but ferns themselves do not attract these flying insects. If you notice flies near your ferns, it is due to other factors in the plant’s environment rather than the fern foliage itself. These conditions often create a suitable breeding ground or food source for various fly species.
Ferns do not naturally attract common household flies. Unlike many flowering plants, ferns do not produce sweet nectar or fragrant blooms to entice pollinators. They also do not bear decaying fruits or strong odors that would appeal to flies seeking food or breeding sites. Healthy fern plants do not serve as a magnet for pests. Their foliage is not a primary food source for most common flies, and they reproduce through spores, not flowers, eliminating sugary attractants. Therefore, the presence of flies indicates an underlying environmental issue rather than an inherent quality of the fern.
Common Reasons for Flies Near Plants
When flies appear around indoor plants, the cause often relates to the conditions around the plant’s soil. Overwatering is a frequent culprit, as consistently wet soil provides an ideal breeding environment for small flies, particularly fungus gnats. These insects thrive in damp conditions and lay their eggs in the moist top layer of potting mix.
Decaying organic matter also attracts various types of flies. This can include fallen leaves, dead plant debris, or even food scraps that might have found their way into the plant pot. Such decomposing material serves as a food source and a breeding ground for flies, including fruit flies and house flies. High humidity and stagnant air contribute to conditions favorable for pest development. Poor air circulation can trap moisture on the soil surface and leaves, creating a perpetually damp environment that pests find appealing.
Identifying Common Plant-Related Pests
Distinguishing between the types of small flies around your plants is helpful for effective management. Fungus gnats are tiny, dark flies, about 1/16 to 1/8 inch long, with slender legs and long antennae, often resembling small mosquitoes. They are weak fliers and are seen hovering near the soil surface or walking across leaves. Their larvae, translucent with distinct black heads, feed on fungi and decaying organic matter in moist soil, and sometimes on plant roots.
Fruit flies are smaller than house flies, often tan or brown with prominent red eyes. They are primarily attracted to fermenting fruits, sugary liquids, and other decaying organic materials. Unlike fungus gnats, they are not specifically drawn to moist soil. House flies are larger, gray with four dark stripes on their thorax, and attracted to a wide variety of decaying organic matter, including garbage and animal waste. If house flies are present, they are likely drawn to general household conditions, not the plant itself.
Effective Fly Prevention and Management
Implementing proper watering practices is a primary step in preventing flies, especially fungus gnats. Allowing the top 1 to 2 inches of soil to dry out completely between waterings deters fungus gnats from laying eggs. Bottom watering, where the plant absorbs water from a saucer below, can also help keep the soil surface drier. Using well-draining potting mix and pots with drainage holes prevents waterlogging, which is a common attractant for flies.
Good housekeeping around plants is also important; promptly remove any dead leaves or fallen plant debris from the pot and surrounding area. Applying a layer of coarse sand, gravel, or horticultural grit about 1/2 inch thick on top of the soil can create a physical barrier, discouraging adult flies from accessing the soil to lay eggs. Yellow sticky traps can effectively capture adult fungus gnats, reducing the flying population. For fruit flies, a DIY trap using apple cider vinegar and a few drops of dish soap in a jar covered with plastic wrap with small holes can be effective.
For persistent fungus gnat issues, beneficial nematodes (microscopic worms) can be applied to the soil. These nematodes, such as Steinernema feltiae, target and kill fungus gnat larvae without harming plants or other beneficial organisms. Ensuring good air circulation around plants, perhaps by occasional gentle fanning or proper spacing, can also help the soil surface dry more quickly and create a less hospitable environment for pests.