You might need to address the issue both inside and outside of your home to get rid of gnats. Finding a combination of treatments that address both indoor and outdoor gnat infestations is the best method to get rid of gnats.
- Find the infestation’s source and eliminate it. The cause could be anything that provides gnats with a decent food source and a place to reproduce, such decaying produce, spilled old food in a sink or trash can, houseplants, and so on.
- To catch and destroy the gnats in the house, buy a gnat trap or gnat zapper or make a homemade gnat trap.
- To eliminate gnats in flight or to treat infestation areas, use a gnat spray.
- Determine and eliminate any potential infestation sources. While discovering the source of outdoor gnat infestations may be more difficult than locating indoor sources, you can start by bagging and removing leaf and clipping piles, moving compost bins, and, if practical, draining standing water areas.
- Between waterings, give the lawn and garden beds additional time to completely dry out.
- If you see gnat swarms, hang gnat traps there and frequently change the fly paper.
- Gnats and other insects can be kept out of your outdoor spaces with the use of electric or flame torches.
- On plants that gnats like, use an outdoor gnat spray or make your own gnat spray.
What outside deters gnats?
- Insect repellents include DEET, citronella, vanilla, pine oil, and dryer sheets. On your porch, you may also utilize fans to keep the air circulating and deter hovering swarms. The effectiveness or toxicity of the various repellent sprays, lanterns, and granules that are available on the market that claim to keep gnats away varies.
- Chemical controls: Gnats can be controlled with foggers, sprays, and pesticides made for flying insects, albeit they aren’t particularly efficient at avoiding more infestations. Chemical controls are less safe and less effective than prevention.
Your neighborhood garden center or online vendors like Planet Natural and Golden Harvest Organics have a selection of organic fungus gnat control items, including as predatory insects and repellents.
Contact your neighborhood agricultural extension office for recommendations tailored to your area if you’re unsure about the type of insect you’re dealing with or if you’re getting bitten.
Why are there gnats on my outdoor plants?
Do your indoor or outdoor potted plants have any small black gnats flying around them? Most likely, these are fungus gnats. When homeowners take the necessary precautions to get rid of these pests, they can be readily controlled even in commercial greenhouses housing thousands of plants.
Fungus gnats are weak flyers that inhabit and surround moist, decomposing material. Usually, plants with fungus gnats have been overwatered. Since gnats like moist, biologically rich soil, this is the main reason the gnat population has risen. Gnat grubs gnaw on the delicate roots of houseplants, but they usually don’t cause enough harm to the plant to be seriously harmed; instead, as they grow and flutter around the plant, they are more of an annoyance. Although they don’t bite, these gnats can be inconvenient. When an infestation is severe, the pests can spread fast from plant to plant, making them increasingly harder to manage.
The amount of rot and fungus in the soil will diminish when a plant is allowed to dry out between waterings, making the pot less inviting to fungus gnats. Make sure that water is never left standing in saucers and that pots have proper drainage. For the gnats to be unable to burrow deep to the organic richness they want, adding a porous top-dressing to the pot, such as sand or gravel, can also assist water drain away from the surface.
There are insecticidal sprays with pyrethrins that can be used at home to combat fungus gnats. If you’re going to treat a houseplant, make sure to move it outside, carefully follow the label’s recommendations, and keep the chemical away from kids and dogs at all times. Another reasonably quick biological control is Bacillus thuringiensis (BT), which kills the larvae in the soil.
The quickest and simplest solution is frequently the best for indoor plants. Repot the infected plant in a pot with drainage using fresh potting soil. When repotting, rinse the plant’s roots gently to remove as much soil as you can, and make sure the hole in the new pot is not blocked. Remove any stems, leaves, or roots that are dead. The gnats will disappear right away.
Before watering a plant, carefully check the moisture content to avoid moisture issues that could quickly cause fungus gnats to reappear. You can use water monitors, or you can just make sure the top 2-3 inches of soil are dry before watering. Fungus gnats can also be repelled by using watering bulbs or other deep-rooted waterers that deliver water only to the roots of the plant rather than the entire container.
When they attack your plants, fungus gnats are undoubtedly annoying. Fortunately, there are several ways to manage or completely get rid of these pests. The best results will come from combining several methods at once, and the gnats will disappear just as quickly as they arrived.
How can I quickly eradicate gnats from my plants?
Size: Fungus gnat adults are very little. They are around the same size as a fruit fly, measuring between 1.5 to 3 mm, or 1/16 to 1/8 of an inch. Larvae of fungus gnats can grow to a length of 1/8 of an inch.
Fungus gnats have wings that are either gray or transparent and are an adult grayish-black color. Despite being much, much smaller in size, they have the appearance of mosquitoes due to their lengthy legs and antennas. Fungus gnats are smaller than fruit flies and have larger legs and antennae.
Activity: Fungus gnats often spend the most of their time buzzing about the outside of potted plants’ soil surfaces or close to their drainage holes. They have a propensity to wander along the ground and only soar briefly because they are not good flyers. They fly more like mosquitoes than fruit flies due to their irregular flight and sluggish speed.
Fungus gnats are absolutely harmless, but annoyingly, they frequently fly into people’s faces and beverages. A few well-placed swats will quickly teach them a lesson.
Fungus Gnat Damage
Fungus gnats are more of a nuisance when they are few in number. In actuality, neither plants nor people are actively harmed by adult gnats. However, if their population becomes out of control, the larvae may begin eating plant roots and cause significant harm. This is particularly harmful to young plants like seedlings because they have few, sensitive roots. The plant disease that causes damping down and the eventual death of seedlings can also be carried by fungus gnats.
Damage from fungus gnats will resemble any other root-related problem, such as root rot. Lower leaves may drop and turn yellow, and the plant’s growth may slacken or cease entirely. In really terrible situations, the entire plant may begin to wilt, and if the roots are severely harmed, the plant may then pass away.
How to Get Rid of Fungus Gnats
The key to controlling fungus gnats is to be consistent. The adults are pretty simple to catch in gnat traps, but since the adult population arrives in cycles, you must make sure that your traps are refilled frequently. Use a mix of the traps indicated here and the additional preventative measures listed in the next section for the best results.
Traps with sticky cards: These traps feature a yellow note card that is adhered with a sticky substance. They work best when they are either fastened to skewers just above the soil or chopped into little squares and positioned directly on top of the soil. On the card, adult gnats will fly or crawl and become stuck in the glue. Use yellow sticky cards instead of blue ones since fungus gnats are drawn to that color. Both can be purchased online as well as at the majority of hardware or garden stores.
Simple and efficient, cider-vinegar traps are made of a shallow container filled with water, liquid dish detergent, and a little bit of apple cider vinegar.
- Making a vinegar-and-cider trap Look for a shallow container. Use a tuna can and fill it halfway with apple cider vinegar and water. (The liquid must be at least one-fourth of an inch deep.) Then, gently stir in a few drops of liquid dish soap to the mixture. Placing the trap inside the container on top of the soil or, ideally, close to the damaged plant’s base will work best. Every few days, check it and replenish with fresh vinegar and water.
Flypaper can also be used to catch fungus gnats. Flypaper ribbons are commonly used to catch outdoor flies in horse barns. However, these traps are frequently overkill for gnats and easily stick to items like furniture, hair, plants, and other surfaces that you don’t want them to.
How to Prevent Fungus Gnats
For best success, combine these preventative measures with the aforementioned traps.
Maintain dry soil: Fungus gnats prefer damp soil, so letting your houseplants air out a little between waterings will help to slow down or halt an infestation. Prior to watering again, wait until the top inch or two of soil have dried up. Also, attempt to let as much time pass without watering. If the dirt is dry on the surface, gnats may not lay their eggs.
Use mosquito dunks (containing helpful bacteria) to prevent mosquito larvae from overcrowding fish ponds, fountains, and other small bodies of water. A dry pellet containing the microorganisms Bacillus thuringiensis subspecies isrealensis makes up the product. The larvae of flying insects, such as mosquitoes, fruit flies, and fungus gnats, are infected by and killed by this advantageous bacteria.
- How to apply mosquito dunks Add a mosquito dip to a gallon jug (or watering can) after filling it with clean water. Before dropping the dunk into the water, it’s a good idea to break it up a bit. Alternatively, you can wait for it to soften before doing so. The dunk should be submerged in the water for as long as possible (at least overnight), after which it should be removed (the dunk can be reused) and the water utilized for plants with fungus gnat infestations. Any larvae that come into touch with the bacteria in the soil will be infected and killed because the infection has already gotten into the water. For at least a few months, repeat this procedure each time you water your plants.
Cover drainage holes: Gnats frequently stay near the tops of pots, but occasionally they will make their way to the drainage holes on the underside and begin laying eggs there as well. If this occurs, cover the drainage holes with a piece of synthetic fabric to keep gnats away while still allowing water to flow freely through. Use tape or rubber bands to secure.
Sand-cover exposed soil: According to some people, fungus gnats can’t reach exposed soil to deposit their eggs if it is covered with a layer of sand that is at least 3/4 inches deep. If combined with the other preventative techniques mentioned above, notably plugging drainage holes, this can be a powerful deterrent.
Do you have any advice for halting or preventing infestations of fungus gnats? Tell us in the remarks section below!
My outside potted plants have fungus gnats; how do I get rid of them?
So your African violets have been invaded by fungus gnats? Let’s now discuss methods for managing both adult flies and fly larvae. Here, we advise using an integrated pest management strategy to cover all your bases and permanently safeguard the inhabitants of your greenhouse and houseplants.
Organic Fungus Gnat Control
Surprisingly, one of my top suggestions for getting rid of these pests is a common household item. You can saturate soil in hydrogen peroxide (the standard topical variety, 3 percent).
Pour a solution of one part hydrogen peroxide to four parts water through the soil in the root zone of the pot until it starts to emerge from the bottom. On contact, fungus gnat larvae are killed by the peroxide.
Neem oil works well as a soil soak to get rid of fungus gnat larvae. Follow the manufacturer’s instructions to dilute the oil with water, then immerse the plant’s roots in the solution. To deter adult gnats, you can additionally spray the plant’s uppermost part.
Neem oil contains concentrated azadirachtin in its natural state. It is safe to use indoors, in greenhouses, gardens, and hydroponically. Use it as directed by the manufacturer, much like you would neem oil.
Sprays containing pyrethrin are also effective at killing fungus gnat larvae. Use pyrethrins by misting the soil’s surface and all plant surfaces with a light mist. A light mist will do; you don’t want the plants to get drenched. Spray the soil exactly where adults usually rest to completely hydrate the top if there are fungus gnat larvae present, then prevent overwatering. Let the soil dry to a depth of at least two. When the issue has passed and the insects are no longer a concern, reapply these after three to four weeks.
Adults and larvae are the targets of a predatory Hypoaspis miles mite. Additionally, it preys on other insects like thrips and springtails, which can be a pest in a greenhouse or garden. Since solitary specimens are more difficult to treat, these are best used outside or in greenhouses.
As you can see, there are numerous biological control treatments available for the removal of fungus gnats. Apply pesticides along with wise cultural habits and effective preventative measures, and you’re good to go!
Cultural Control of Fungus Gnats
Avoid flooding your growing media. These insects thrive in the moist growing medium found in houseplants. Do not leave standing water in saucers next to growing medium or below houseplants for an extended period of time. Keep your growth medium away from your potted greenhouse residents and fix any irrigation system leaks that develop. To get rid of any larvae that may be feasting on the organic elements in your compost, pasteurize the growing medium. If you don’t like the notion of doing it yourself, use heated commercial growing medium mixtures. While you take care of the issue, keep any sick plant material and growth medium away from other people.
Biological Removal of Fungus Gnats
Fungus gnat larvae can be killed by a specific strain of bacteria called Bacillus thuringiensis var. israelensis. Most commercial BT sprays do not contain these bacteria, although they are also present as active components in some commercial products. You should see a reduction in your fungus gnat issues if you use them to fertilize your growth media.
By scattering Mosquito Bits or Mosquito Dunks over the soil’s surface and soaking them in, you can also introduce this bacterium. These are suitable for usage both inside and outside. They aren’t just used to kill mosquitoes! As they decompose, Bacillus thuringiensis var. israelensis is released into your soil, where it can begin to kill larvae. Mosquito dunks are more substantial and take longer to work.
The eradication of the fungus gnat larvae might also be greatly aided by the species of beneficial nematodes. The fungus gnat larvae and many other soil-dwelling pests will be eliminated by these microscopic soil dwellers, which you cannot see. Use a pot popper to incorporate these nematodes into the soil when treating an indoor plant. Commercial formulations can cover a larger garden or the entire yard since they uniformly distribute the nematodes with water.
Be warned that using a hydrogen peroxide soil drench and helpful nematodes at the same time will kill the nematodes! Nematodes should not be added back into the soil for at least a few weeks following the infestation. Nematodes should be used in cooler weather if you’re working outside because heat will kill them before they can perform their job. Keep in mind that you must apply more than once, twice a year.