Garden Guides, How to Get Rid of Gnats on an Orchid Plant

How to Get Rid of Gnats on an Orchid Plant

By: Joshua Duvauchelle

21 September, 2017

Orchids are rarely afflicted by insect pests except in the case of fungus gnats. These gnats are symptoms of improper orchid care. The small flying insects and their larvae feed upon decaying organic material in the orchid plant’s potting material, and also on the plant’s roots. If they’re not kept in check, the gnat population can explode and become both a nuisance and a health hazard to your plant.

Change your orchid plant’s potting material. Only use material that decomposes very slowly, such as coconut fiber and charcoal, and change this regularly every 2 to 3 months. Alternatively, use a material that is inorganic, such as perlite. This removes the decaying material on which the gnats feed.

Reduce watering as much as possible, as the gnats and their larvae prefer a humid and moist environment. Always let the orchid plant’s potting material and roots dry out between watering.

Avoid overfertilizing, as this further encourages gnats to congregate on your orchids. Nutrient needs vary widely by orchid species. Consult the nursery or orchid fancier from which you purchased the plant for species-specific fertilization requirements.

Trap and kill the gnats if the preventative strategies do not sufficiently reduce the gnat population on your plants. Use the yellow fly traps used to capture flies and aphids. Setup the traps adjacent to your orchid plant, or hang them from your orchid’s leaves. The gnats are drawn to the yellow color where they become stuck and die.

Rid Of Gnats On An Orchid Plant

Inspect your orchid daily for fungus gnats. The wings are clear to light gray and the legs are slender. You may see these pests hovering around the plant. Fungus gnat larvae feed on the fungi that grow in warm, fertile, overly moist soil. Allow the top 1 inch of potting soil to dry out completely between waterings. Do not over-feed the plant. Follow the packaging instructions. Remove dropped or shed plant material and debris from the potting medium surface as soon as you notice it. Glue or staple the end of a wood craft stick to the yellow card. Package the yellow sticky traps up in a plastic bag for disposal in the trash. The gnat larvae will climb out of the soil to feed on the potato within a day or two. Cover the top of the cup with a small piece of clear plastic wrap. The soap in the liquid breaks the surface tension and causes the lightweight gnats to sink rather than walk safely across it.

How to Get Rid of Gnats on an Orchid Plant

Control gnats on orchids with smart cultural practices.

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While orchids are often considered the elite of blooming plants among flower enthusiasts, even these regal beauties are subject to fungus gnat infestations. The pests are not typically a health concern for indoor plants, although they are annoying and unsightly. The silver lining is that the presence of fungus gnats is a good indication that something is not quite perfect with how you’re growing your orchids. Fortunately, treatment for fungus gnats seldom requires chemicals. Combine sound cultural practices with some specific treatments to get rid of gnats invading your orchids.

Cultural Controls

Inspect your orchid daily for fungus gnats. You will probably notice the adults first. Look for them on the flowers, foliage, pot rim and soil. Delicate-looking adult fungus gnats are between 1/16 and 1/8 inch long and look somewhat like mosquitoes. The wings are clear to light gray and the legs are slender. The antennae are longer than the insect’s head and are segmented. You may see these pests hovering around the plant. Once you discover adults, there may already be eggs or larvae in the potting medium.

Repot the orchid in a well-draining medium that is slow to decay. The best soils contain slow-decaying organic materials such as coconut chunks or fiber and charcoal. Perlite is a good inorganic ingredient. Fungus gnat larvae feed on the fungi that grow in warm, fertile, overly moist soil. They also consume decaying organic matter, such as decomposing potting media and rotting plant roots. The older the potting media is, the more likely it is to be infested with gnat larvae.

Allow the top 1 inch of potting soil to dry out completely between waterings. Water your orchid only when necessary. Empty the saucer often and do not allow water to accumulate in it. Fungus gnat eggs and larvae require moist soil and soon die if they dry out.

Fertilize your orchid monthly with a 30-10-10 orchid food to keep it healthy. Do not over-feed the plant. Follow the packaging instructions.

Trim dying or dead vegetation off the orchid immediately to avoid attracting adult fungus gnats. Pay particular attention to areas of the plant near the soil line. Remove dropped or shed plant material and debris from the potting medium surface as soon as you notice it.

Physical Controls

Use a yellow marker or highlighter to color both sides of an index card to create a sticky trap plant stake. Glue or staple the end of a wood craft stick to the yellow card. Coat both sides of the card generously with petroleum jelly. Poke the stick into the orchid’s potting soil. Package the yellow sticky traps up in a plastic bag for disposal in the trash. This tool is highly effective for monitoring the gnat population as it eliminates flying adults, which are attracted to yellow objects.

Cut a raw potato in 1/2-inch pieces. Set several of them on the surface of the orchid’s potting medium. The gnat larvae will climb out of the soil to feed on the potato within a day or two. Seal the pieces of potato up in a plastic bag and discard in the trash.

Pour about 1/2 inch of apple cider vinegar, beer or fruit juice in the bottom of a disposable plastic cup. Stir in several drops of liquid dish soap. Cover the top of the cup with a small piece of clear plastic wrap. Secure it in place with tape or a rubber band. Cut a 1/4-inch hole in the center of the plastic wrap with scissors. Tape over the hole when you are through with the trap and dump it in the trash. Adult fungus gnats are attracted to the fermentation that occurs in apple cider vinegar, beer and fruit juices and seek to lay eggs on it. The pests will enter the trap through the hole and go for the liquid, where they will drown. The soap in the liquid breaks the surface tension and causes the lightweight gnats to sink rather than walk safely across it.

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How To Treat Dark Spots On Orchid Leaves

Orchids are plants that hardly get sick. But when they do get sick, the most common disorder is the brown spots on the leaves.

What causes the brown spots?

Most commonly, the brown spots occur after pathogenic mold infection (fungi).
Sometimes, these brown spots are caused by bacteria.

The infection causes are diverse, but these are the most common ones:

A latent infection that is triggered when the plant receives improper living conditions (excessive humidity, lack of humidity etc.);
Contact with other infected plants;
Infection caused in situations where plant suffers damage during repotting process or because of accidental injuries.

Where these spots occur?

These brown spots (sometimes black) can occur on all plant organs: roots, leaves and flowers.

How to prevent the infection?

By providing minimum conditions required by the orchids;
By keeping the orchid in a healthy state;
By proper fertilization.

How to treat diseased orchids?

Plants showing signs of disease are isolated from the healthy ones.
If the illness is in an early stage, the removal of infected parts is recommended, whether it’s the flowers, leaves or roots.
If the disease tends to expand to the whole plant, it requires quick intervention, ie: changing the pot and the substrate, removing affected parties, sinking the roots in a fungicide solution and spraying the rest of the plant with the same solution.

Instead of fungicide you can also use a solution made of 4-5 crushed garlic cloves, over which you poured 1 liter of boiling water. After cooling, filter the solution and use it in the same manner as described above.
In serious cases, you have to remove the floral stem, especially if it has been aesthetically compromised.
The rescue action should particularly target the bud (the area where the new leaves appear).
In some situations, you must get rid of the plant.


Working with fungicides requires attention, because they are highly toxic substances!
Follow the instructions for preparing the solution.
Since these treatments are homemade, it is advisable to apply them in the bathtub.
Thoroughly wash the tub after the operation.

Image Credits: Orchid Geeks

An Ant Infestation on the Orchids

Ants protect pests, like aphids, on orchid plants, to ensure a continuous source of honeydew.

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The orchid family is vast, containing approximately 20,000 species of plants that are divided into more than 700 genera. Orchids are prized for their beautiful, exotic blooms, although they can be finicky plants to care for. Ants are a common nuisance on orchids. Ant infestations are alarming, but controllable. Usually the presence of ants on your orchids indicates another type of pest infestation.

Why Ants Infest Orchids

Ants don’t usually cause direct damage to an orchid, but their presence can indicate an infestation of scale insects, mealybugs or aphids. Ants are attracted to a sweet substance called honeydew, which is secreted by these insects which feed on your orchid plant’s sap. Some orchid species, such as cymbidiums, also secrete honeydew on the flower spikes which may attract ants. To control ant infestations on orchids, treat infestations of sucking insects, or block the ants’ path to the plant. Ants will protect sucking insects, so it is usually necessary to eliminate the ants first.

Controlling and Preventing Ants

To begin controlling ant infestations, pour a diluted solution of an acephate- or carbaryl-based insecticide at a rate of 1 teaspoon per 1 gallon of water through the pot. Apply the insecticide outdoors to allow ants to leave the pot without invading your home. Spray the foliage with the same solution to kill any ants that escape the pot. Leave the orchid in a shaded spot outside to protect the wet foliage from sunburn, and to allow the insecticide time to kill the remaining ants. Follow this with control measures to eradicate any other pests that remain. To prevent ants from infesting your orchid in the future, set the pot on a small bench or platform and place the platform in a shallow dish filled with soapy water. Do not place the orchid pot directly in the water.

Signs of Other Pests

Inspect your orchid for evidence of scale insects, mealybugs or aphids. These pests are hard to see, but scale and mealybugs will cause chlorotic areas to develop on the leaves which turn yellow and may darken, resulting in premature leaf drop. Mealybugs also excrete a white, waxy substance that covers their bodies, and resembles a wooly mold on the leaves and stems of an orchid. Scales are tiny, brown or whitish insects that are oval-shaped and may look like tiny bumps on your orchid’s leaves and stems. Aphids attack buds, flowers and new growth, and may cause buds to fail to open. Aphids may be yellow, green, brown, black or red, depending on the species.

Control Orchid Pests That Attract Ants

Mealybugs, aphids and scale can usually be controlled using a combination of mechanical and cultural methods. Remove all visible insects by hand-picking or using a cotton swab soaked in 70 or 90 percent isopropyl alcohol. Repeat picking off visible insects every three days for about two weeks. Never use other alcohols, such as methanol or ethanol, because these will damage your orchid’s leaves. Remove old flowers and leaf sheaths to eliminate their hiding places. If the infestation is severe, repot your orchid in a clean pot with new potting media, removing all visible pests from the roots before planting. Insecticidal soaps are also effective in controlling infestations, but use only those that are labeled for use on orchids and target the specific pest you’re trying to control.

How to Treat Ants on Orchid Plants

21 September, 2017

Orchids are rarely attractants to pests but ants can become attracted to the sticky residue on some orchid stems. Ants can also be attracted to the moisture in the orchid’s potting medium particularly in dry climates or during times of drought when water is hard to come by. Orchids are very sensitive to chemical insecticides so cultural measures and physical traps and barriers are preferred to chemical intervention.

Flush your orchid plant and its planting medium with running tepid water at a medium to strong rate of flow for several minutes to wash out the ants. Run water down the bottom third of the stem first to prevent the ants from running up the stem. Squash any ants that climb up onto the stem or your hands during the flushing process. Repeating this process every two to three days for a week should put an end to a mild infestation.

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Change out the orchid bark around the plant roots when flushing the ants with water is insufficient to displace them or they have laid eggs in the medium. Pull the plant from its pot and brush away all of the potting medium from the roots and discard it in the trash or compost pile outdoors.

Rinse the lower orchid stem and roots well in tepid water. Set the plant aside and wash the plant pot with hot water and soap and rise well to ensure there are no ants or eggs remaining. Replace the plant in the pot and fill in with fresh orchid medium snugly to stabilize the plant. Water in well to wet the medium and allow excess water to drain away.

Set commercial ant traps in the location where your orchids are kept. These will attract the orchids without causing any harm to the orchids themselves or the ambient air. Leave the traps in place for the recommended period or until the any problem dissipates. If you have animals in your home be sure to use animal safe ant traps.

Create a moisture tray for your orchid with a shallow tray filled with pebbles and water. Set the orchid atop the pebbles to serve as a moat to keep the ants at bay and also provide ambient humidity that the orchid will thrive in. Adding a few drops of liquid dish soap or mineral oil to the water can be an extra line of defense against the ants. Refill the water as it evaporates to keep the tray full at all times.

Podura in an orchid: how to get rid?

Orchids are plants that don’t get sick so easily, but when they do, the most common affection is the appearance of brown spots on the leaves.

Which is the cause of brown spots on orchid leaves?

1. Usually, brown spots appear if the plant got infected with pathogenic molds.
2. Sometimes the diseases are caused by bacteria.

How does the infection occur?

The most common ways to fungi infection are:
1. A latent infection appears wen the plant suffers from improper living conditions (excessive humidity, lack of humidity, etc.);
2. Getting into contact with other infected plants;
3. Sometimes the infection appears during transplantation when the plant suffers injuries due to transplantation or accidental injury to its organs.

How to prevent the fungi infection?

1. Providing at least the minimum requirements for orchids;
2. Keeping the plant in an optimal state of health;
3. Proper fertilization

How are sick orchids treated?

1. Isolate the plants showing signs of disease from the healthy ones.
2. If the illness is at an early stage, it’s recommended to remove the infected “organs”, whether it will be flowers, leaves or roots.
3. If the disease tends to spread to the entire plant, rapid intervention is required, which means changing the pot and the soil, removing the affected parts, sinking the roots into a fungicide solution, and spraying the same solution on the rest of the plant.
4. Instead of a fungicide, you can also use a solution made of 4-5 crushed garlic cloves over which 1 liter of boiling water is poured. After cooling, the solution is filtered and used in the same manner as above.
5. In some severe cases, you must give up the floral stem, especially if it has been compromised aesthetically.
6. The rescue action should in particular target growth buds (the area where new leaves appear).
7. In some situations, you must “bury” the plant.

1. Working with fungicides requires greatest attention, these being highly toxic substances!
2. Follow the instructions before preparing the solution.
3. Pay attention to children!
4. Because these treatments are done in the house, it’s advisable to prepare the solution in the bathtub.
5. Thoroughly wash the tub after the operation is done.

Image Credits: Orchidbliss

Growing Indoor Orchids

These Delicate Flowers Are Easier to Grow Than Many People Think

Viktoriya Stoeva / The Spruce

To grow an orchid, you have to think like an orchid. The golden rule for orchid success is to duplicate the plant’s natural conditions as closely as possible. In nature, most orchids are epiphytes, meaning they grow on other objects, clinging to rough bark or even stone. The showy orchids favored by most people are usually either phalaenopsis hybrids (so-called moth orchids) or dendrobium hybrids.

Optimal Growing Conditions for Orchid Plants

These plants thrive in strong light, but not direct late-afternoon sunlight (although dendrobiums can handle more sun). They also need high humidity and airflow around the roots. They need regular periods of drying alternated with heavy watering. Orchids do best in temperatures above 50 degrees but below 85 degrees.

The closer you can come to creating these conditions, the more success and better blooms you will have.

Most store-bought orchids come packaged in cheap plastic pots with the roots packed in soaked moss. Obviously, this violates two of the main rules of successful growth. There is no air flow around the roots, and the roots are never given a chance to completely dry out. Thus, the plant cannot breathe and root rot is inevitable.

Orchid roots are highly specialized organs designed to soak up water very quickly and breathe. They do not extract nutrients from the soil.​​

Repotting Orchids for Success

The first step with any store-bought orchid is to enjoy the bloom. Don’t attempt to re-pot a flowering plant.

After the bloom is done, go ahead and cut off the dead flower spike with sterile snippers and repot the plant. Orchids should be potted into specialized orchid pots in an orchid mixture. Orchid pots feature wide drainage slits so water will literally run through the pot. They are widely available. Orchid potting mixture is usually composed of several chunky ingredients, including pine bark, charcoal, and even styrofoam.

To re-pot your orchid, follow these steps:

Remove it from the plastic pot and carefully remove as much of the moss as you can. Healthy roots should be white and firm, with a small green growing point.

Cut away any shriveled, rotten or blackened roots.

Set the plant into the pot and fill in around it with potting mixture. The plant should be firmly situated, but it will not be completely anchored. Eventually, new roots will grow through the potting mixture and attach to the pot itself, thus anchoring your plant.

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Once it’s re-potted, find a good spot. An east-facing window with a few hours of mild morning sun is perfect. To provide the necessary humidity and catch run-off water, put the plant into a wide, deep tray and fill the tray with gravel.

Orchid Plant Care

Aphid Control for Orchids

Author: Melanie Dearringer 7 Comments

Orchids have few problematic pests, especially when grown indoors or in greenhouses. But, there are a several insects that can devastate an orchid collection. Aphids are one. There are more varieties of aphids found in temperate climates than in the tropical regions that many orchids are native too. While there are a few problems with aphids in tropical climates, when orchids are grown in homes and greenhouses in temperate climates they are more susceptible to these tiny predators. With some prevention measures and a few control techniques, you can save your orchid collection from an aphid attack.

Aphids and Orchids

Aphids Can Harm Orchids

Aphids are small insects, ranging in size from 1-10 millimeters. They have soft bodies that can be green, black, brown, or even translucent. There are 4,400 different species of aphids. Fortunately, only 250 of those species are problematic for agriculture and gardening. Fewer than that are a problem for orchids. Aphids get their nourishment by sucking phloem sap from the plants they are inhabiting. In turn, they produce a sticky substance called honeydew. Ants often thrive on honeydew and in some situations will even farm aphids, protecting them from predators. Another aspect of aphids that makes them difficult to manage, is their ability to reproduce. Aphids can reproduce sexually or asexually and they can give birth to nymphs or lay eggs. This happens several times a year and several generations can reproduce within the same year. An aphid population can explode very quickly. When a plant becomes unfavorable to survival or overpopulated, an aphid can produce winged nymphs that will fly to colonize a new plant.


Because aphids are soft bodied, they have many predators. Their most famous predator may be the lady bug. Lacewing larvae and crab spiders are among other significant predators. Aphids are also very susceptible to various fungi and even weather such as heavy rain or too much heat. These susceptibilities give hope for management despite the prolific nature of aphids.

Signs of Infestation

You can tell your plant is infested with aphids when leaves begin to wilt and even drop. Aphids will be visible around the flower and flower spike, especially where there is new growth, and on the underside of leaves. Aphids are particularly damaging to plants in three ways. First, because they eat the sap of the plant, it puts stress on the plant and prevents important sugars and nutrients from helping the plants grow well. Second, aphids carry harmful viruses with them that can be transferred and damaging to a plant. Lastly, the honeydew that aphids leave behind is an excellent growing environment for harmful fungi.


There are several ways you can prevent your orchid collection from being damaged by aphids. If the collection is kept in your home, it is not likely that aphids will invade, however, they may hitch a ride on an orchid purchased from a supplier and then spread to other plants. Any time you purchase a new orchid, no matter how trusted the supplier, keep it quarantined for three weeks before you place it with the rest of the collection. This will not only protect your old plants from aphids, but a host of other insect invasions as well. During this three week quarantine, check your plant daily for insects. If they are caught before there is a serious outbreak they are much easier to remove. Another simple method for prevention is to keep a catnip, garlic, or mint plant near your collection. Aphids dislike the smell of these plants and are not likely to settle near them.

Closely monitoring all of your orchid plants will help you catch an aphid infestation before it explodes. If caught early aphids can be significantly easier to control than when the population is already established and rapidly reproducing. Be sure to examine each plant closely, looking under leaves and at the connections between the stalks and leaves and around new buds.

Methods of Control

Aphids can easily be knocked off your orchid by simply directing a stream of water at the plant where the bugs are present. If there are any heavily infested areas, you may want to consider pruning those parts of the plant. If pruning is not an option, you can use biological controls. Biological control is the introduction of beneficial insects, like the larva of lacewings, and is often used in a greenhouse setting.

Insecticidal soaps are another safe option. The soap removes the outer layer of the aphid causing the aphid to die from exposure. The soap must hit each individual pest in order to effectively control the outbreak. It may take several applications to make contact with all of the aphids. However, be cautious as too many applications will eventually damage the plant and any application may cause damage to the flowers. Soaps should be used no more than three times in a row. If the aphid population is still not under control, you may need to try a new method of pest management.

Horticultural oils work similarly to soaps. On contact, they suffocate the aphids. Neem oil or other oils applied every two weeks should control the population. Do not apply oils in direct sun, in environmental temperatures higher than 85 degrees, or high humidity.

Yellow card sticky traps can be used to prevent the spread of winged aphids from one plant to another. Aphids are naturally attracted to yellow and when beginning to colonize a new plant will be drawn to the yellow cards. This method cannot be expected to eradicate an aphid infestation, but it can be a good indicator of an infestation and it can help prevent the spread of aphids.

Points to Remember

To keep your orchids safe from aphids remember the following points:

  • Always quarantine a new plant to prevent the introduction of aphids to your existing collection.
  • Monitor vigilantly, a few aphids are easier to get rid of than a large infestation on several plants.
  • Be sure to correctly identify any new pest. Different pests require different control methods.
  • The safest control methods for indoor orchids are soaps or oil applications along with manual removal of adult aphids.
  • It may take more than one application.

With your diligence and careful control, aphid infestations can be controlled and do not have to be the end of your beautiful orchid collection.

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