The uniquely shaped flowers of the bat faced cuphea make it a beloved houseplant However, these plants can become plagued by pesky fungus gnats If left uncontrolled, fungus gnats can damage plant roots and stunt growth. Getting rid of fungus gnats requires diligence, but it can be done. Follow this comprehensive guide to protect your cuphea plant from these irritating insects.
Identifying Fungus Gnats
The first step is confirming you are dealing with fungus gnats and not some other flying pest Here are the telltale signs
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Tiny dark flies, about 1/8 inch long, hovering around the plant’s soil. They resemble mosquitoes.
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Larvae in the top layers of soil that look like tiny whitish worms.
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Adults flying up when the soil is disturbed.
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Possible root damage resulting in poor plant health.
Inspect soil closely, especially after watering. If you see the flies, larvae, or symptoms, fungus gnats have likely infested your cuphea.
Non-Chemical Fungus Gnat Controls
Start by trying these organic, non-chemical methods to eliminate fungus gnats:
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Allow the top inch of soil to dry out between waterings. Fungus gnats need moisture to breed.
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Use yellow sticky traps near soil level to catch adults. Replace traps weekly.
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Sprinkle a thin layer of sand or cinnamon on the soil, which deters adults from laying eggs.
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Remove and dispose of the top inch of soil which contains larvae and eggs. Replace with sterile soil.
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Introduce beneficial nematodes to the soil, which prey on fungus gnat larvae.
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Repot the plant in a container with drainage holes using sterile potting mix.
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Set pots in trays of water mixed with mosquito dunks, which contain bacteria deadly to gnats.
Chemical Fungus Gnat Controls
If non-chemical methods are ineffective, these chemical treatments may be required:
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Insecticidal soaps coat and kill larvae on contact within hours. Spray soil until saturated.
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Bacillus thuringiensis (Bt) releases bacteria that target fungus gnat larvae when ingested. Apply as a soil drench.
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Insect growth regulators like azadirachtin disrupt the molting process, killing larvae. Use as a soil drench.
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Systemic insecticides containing imidacloprid are taken up by plants’ vascular systems, poisoning larvae feeding on roots.
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Botanical insecticides derived from plants, like pyrethrins, provide quick knockdown of larvae. Spray over soil.
No matter what pesticide you use, carefully follow all label instructions for effectiveness and safety. Isolate and treat infested plants promptly to avoid spreading fungus gnats.
Preventing Fungus Gnat Infestations
Prevention is the best way to avoid battling fungus gnats:
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Allow plants to dry adequately between waterings.
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Discard excess water in plant saucers after watering.
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Use sterile potting media when repotting plants.
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Inspect new plants closely before bringing them home.
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Clean up fallen leaves and debris which can harbor larva.
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Cover soil with sand, pebbles, or mosquito dunk pieces.
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Introduce beneficial predatory mites which eat fungus gnat larvae.
With persistence using both non-chemical and chemical control methods, you can eliminate fungus gnats from your cherished cuphea plant. Consistent pest monitoring and prevention will help avoid future infestations of these nuisance pests.
Recovering Damaged Cuphea Plants
If fungus gnats are left uncontrolled, they can injure your plant’s roots and leave it stressed. Here are some tips to rehabilitate damaged cuphea plants:
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Prune away any dead or dying roots, stems and leaves, which can harbor pests.
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Repot the plant in fresh sterile potting mix to encourage new root growth.
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Treat the plant with a gentle liquid fertilizer or compost tea to restore nutrients.
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Keep the plant well-watered while avoiding oversaturation as new roots establish.
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Consider using a rooting hormone to stimulate root regeneration.
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Maintain warm temperatures of 65-75°F and moderate humidity around 50% as the plant recovers.
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Be patient, as root recovery can take several weeks. New foliage will indicate the roots are healing.
With attentive care and treatment, your cuphea can bounce back after fungus gnat damage. Remember to keep monitoring for recurring gnats and immediately treat any you find. Stay vigilant to keep these pesky insects from invading your plants again.
How to Get Rid of Fungus Gnats
I tried several methods to kill my herd of intruders before I finally found a solution. But first, here are some frequently-mentioned remedies that didnt work for me or were just too inconvenient to try:
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Apple Cider Vinegar
Every time I’ve looked up a method to get rid of fungus gnats or fruit flies, the mixture of apple cider vinegar, dish soap, and water is always at the top of the list – and it has NEVER worked for me. This time was no exception.
It seems like the smell is just as obnoxious to the bugs as it is to my nose, and no one wants to go near the stuff.
Neem Oil & Other Sprays
Neem oil is a naturally occurring pesticide and came up frequently as an option to rid my life of fungus gnats, so I gave it a whirl. But I had some issues with it.
First of all, the suggested application was to drench my plants in neem oil – including the tops AND bottoms of leaves as well as the stems. This proved to be a really messy endeavor, especially when dealing with an oily substance.
On top of that, although the smell isn’t super strong, I definitely wasn’t a fan. Needless to say, this method didn’t work either.
I also tried other sprays that claimed to kill fungus gnats but to no avail.
Waiting Longer Between Waterings
Because fungus gnats thrive off the decaying material in soil, which is exacerbated by dampness, the idea behind this method makes sense. This seemed to work in the short term, but I ended up needing to water my plants before they died and the gnat problem picked right back up.
Drench in Water
I realize this remedy seems counterintuitive to the recommendation above. Let me explain.
The idea isn’t to just water your plants into oblivion, but rather to either put them in the shower and give them a good spray or dunk them in a bath to wash away the pests.
The problem here is that A) not all of my pots have drainage holes or nursery pots (something I’m working on switching out, don’t @ me), and B) it’s unlikely that this would wash ALL the larvae away. I didn’t even bother giving this idea a try.
Repotting
I have A LOT of plants, so it would have been wildly inconvenient to repot them all, but if you only have a couple this would be a viable option. Just make sure you throw out the old soil and maybe give your plant a good rinse before repotting.
Will Fungus Gnats Hurt My Plants?
Aside from being unbearably annoying, adult fungus gnats wont directly harm your plants. I say “directly” because their offspring most definitely can.
Fungus gnat larvae survive by eating fungi, organic matter in the soil, and the roots of plants, which can cause damage.
How to Get Rid of Fungus Gnats | DIY Remedy | creative explained
FAQ
What do you spray for fungus gnats in plants?
How do you get rid of fungus gnats in plant pots?
Can I spray my plants with vinegar to get rid of gnats?
How do you control fungus gnat infestation?
How to get rid of fungus gnats in houseplant soil?
Here is a list of helpful natural ways to get rid of fungus gnats and kill these bugs in houseplant soil: Hydrogen peroxide to kill off fungus gnat larvae —Make a soil drench with hydrogen peroxide 3% to flush the soil and kill these bugs in the plant soil. This remedy helps kill off gnat larvae in the soil to break their lifecycle.
How do you get rid of gnats in soil?
Neem oil, hydrogen peroxide soil drenches, beneficial nematodes, and pyrethrins are all excellent for killing gnats, their eggs and larvae in plant pot soil. You can also use yellow sticky traps to catch and kill flying gnats. Fungus gnats are from the superfamily Sciaroidea, and their larvae feed on the fungus growing in soil.
Are fungus gnats a problem?
Fungus gnats are particularly pesky but common houseplant pests. They might be difficult to spot early on and multiply quickly. Fungus gnat larvae feed on the roots of plants, especially potted house plants, which can cause plants to wither and die if the infestation isn’t addressed.
How do you get rid of fungus gnats in potatoes?
Here’s an easy test: Placing a 1/4-inch slice of raw potato on the soil surface. After a few days, check the underside of that potato for tiny black-capped fungus gnat “worms” (larvae). If you find any, try any or all of the following solutions to get rid of fungus gnats in plants.