How To Kill Thrips On Houseplants

It might be advisable to just throw away the plant in cases where the infestation was severe. In many cases, if the plant is highly infested, it is not worth the fight unless it is something unusual or valuable to you.

Please be aware that some plants, such as some succulents, ferns, and begonias, may be sensitive to insecticidal soap.

Test the plant beforehand if you’re applying insecticidal soap on it for the first time. Wait 24 hours after spraying one or two leaves. Spray the whole plant if everything seems to be in order.

When you spray your plants while they are still moist, keep them out of the sun.

Try a different spray if you see that the leaves have a negative impact. Always carefully study the label since it will frequently specify which plants the product is not suitable for.

The method I employ to cure thrips is as follows:

Wash down your plant

Take your plant to a sink or shower, or even outdoors if you’d like if it’s warm enough. Rinse your entire plant, including the undersides of the leaves, as thoroughly as you can.

Spray with insecticidal soap

After the plant has dried, I like to sprinkle it with a nice insecticidal soap. Try your best to cover every surface, including the undersides of the leaves. Spray every available surface.

Be sure to spray any flowers you have that appear to be impacted (or just snip them off and throw them away).

Both nymphs and adults of thrips will be killed by the insecticidal soap if they come into contact with the spray.

You can use the effective insecticidal soap made by Bonide. It is believed that insecticidal soaps are safe for both people and animals to use.

Apply a systemic insecticide

Because the thrips eggs are located inside the plant’s tissue beneath the leaf’s surface, as I described earlier in this piece, no spray insecticide will kill them.

A systemic pesticide can help in this situation. You can water in your soil after applying the necessary dose of systemic insecticide.

The insecticide will then be absorbed by the plant from the roots. Thrips will effectively become poisoned when they feed on your plant, which will help halt the lifecycle from continuing.

For this, I employ Bonide Systemic Houseplant Insect Control. Use only as instructed on the label, and apply as often as advised.

In the United States, this is accessible for domestic use, but it appears to be unavailable in several nations, like Canada and others.

A systemic pesticide combined with attentive insecticidal soap application is highly beneficial.

If a systemic treatment is not an option for you or you are unable to get one, you can still treat with insecticidal soap, but it will take a little more work and many weekly treatments spread out over a few weeks.

Use sticky traps to capture adult thrips

Adult fungus gnats are caught in yellow sticky traps, which you may already be extremely familiar with. They will tackle thrips as well!

Put your yellow sticky traps in the container with your infected plants, and watch them to see when thrips are captured.

You can also use blue sticky traps because thrips are drawn to these in particular. Even better, you can combine them with yellow sticky traps. Put a yellow stick trap close to the soil at the base of your plant, and you might also dangle a blue stick trap directly above it.

Since they can no longer lay eggs on your plants, catching as many as you can on sticky traps will help reduce the number.

Repeat steps 2 and 3 weekly

Do not omit this phase! This is a crucial one! Even after you stop noticing new thrips damage, it is crucial to repeat steps 2 and 3 (spraying your plant with insecticidal soap) every week.

As there are constantly thrips in various stages of their life cycle, try to be diligent and perform this task once every week to eliminate as many thrips as you can.

Finally, I wanted to bring up a practice that I’ve heard many plant parents use. Some people may completely cleanse the soil from the roots before repotting them in brand-new potting soil.

I advise against using this strategy for the following reasons:

  • The reason you changed the soil in the first place can still be defeated if thrips are dropping into your new soil from the foliage above. William Kirk, an entomology professor, made this statement and noted that although thrips occasionally pupate on plants, most often they do so on the soil or the soil’s surface.
  • Additionally, completely removing the soil from your plant would unnecessarily shock it. Stressed plants are more vulnerable to additional insect attacks.

Prune Thrip-Damaged Plants

Remove any leaves, blossoms, or stems that have been thrip-damaged and place them in a garbage container. To prevent the thrips from spreading if the plant is severely affected, completely separate it from the rest of your plants. The greatest move you can make as a plant parent could be to throw the entire thrip-infested plant into the garbage, depending on how attached you are to the plant. Throwing the plant away is a difficult but effective thrip therapy.

Wash Thrips Off Plants With Water

With a spray from the hose, remove thrips from the leaves of outdoor plants. Pay attention to the areas of the leaves where they congregate. Use a spray bottle to apply a soap-and-water mixture on the foliage of indoor plants. Saturate every area of the infected plant with a mixture of a gallon of water and two teaspoons of dish soap. Although it works to control thrips, it won’t stop them from coming back.

Spray Plants With Neem Oil

A natural pesticide derived from the neem tree is called neem oil. For gardeners, it is essential because, unlike synthetic pesticides, it kills undesirable insects like thrips and white flies without affecting beneficial insects like bees and other pollinators. Neem oil works by blocking the hormones that drive insects to feed and reproduce.

Here is how to use neem oil to get rid of thrips:

  • Get rid of the thrips from your plant.
  • One gallon of water should contain 4 teaspoons of neem oil and 2 teaspoons of dishwashing soap.
  • Spray on the plant’s infected areas.

Neem oil doesn’t instantly kill thrips, so you won’t get to enjoy seeing the pests that destroyed your plant wheeze and pass away. Systematic pest control is provided with neem oil. Neem oil is absorbed by your plant into its tissue, where its components will prevent subsequent insect attempts to consume the plant. It is comparable to a plant vaccine.

Spray Plants With Pyrethrin

A natural thrips-killing pesticide derived from chrysanthemums is called pyrethrin. Pyrethrin must be sprayed on infected plants twice, with a 4-day interval between each application. Concerned with the environment? Use pyrethrin pesticides instead of pyrethroid pesticides, which have synthetic chemicals added to make them more harmful to insects. Pyrethrin pesticides are safer. If pyrethroids enter streams, they can also destroy fish and honey bees. Before you spray, check the label to be sure you’re getting what you expect.

How do you get rid of thrips in your home?

You can take care of the leaves, stems, and blooms on your houseplant using a few different techniques. The first step is to spray your plant with water to remove any thrips that may be present. Repeat this frequently while keeping a close eye on the plants. Insecticidal soaps and neem oil sprays are both secure and reliable options if this doesn’t work or if you wish to try a spray. Make careful you apply the product according to the manufacturer’s instructions.

Since the nymphs, or young thrips, may be present in your soil, you may wish to treat it to ensure that you completely eradicate all thrips. The soil can be treated with a systemic insecticide for houseplants to control a variety of pests. The plant will absorb the systemic pesticide and defend itself against a range of pests, including thrips, by simply watering it into the plant.

Right spray, right insect.

Not all insects can be controlled with soapy water. That’s great. It enables us to keep good insects in the garden. Additionally, it implies that not all insects will be disturbed by soap.

The ideal candidates for control with soapy water are little, soft-bodied insects. Spraying with soapy water is an effective method for controlling aphids, whiteflies, thrips, and mites. Caterpillars and beetles, notably Japanese beetles (sorry! ), are sturdy, large-bodied insects that are unlikely to be harmed.

Take aim.

In order for the soapy water to be effective, the bug must be both touched and coated by it. To reach insects on the underside of leaves, this probably entails turning over leaves. If the spray is high pressure, an added benefit is that many of these small-bodied insects will be knocked off the plant, giving you both chemical and physical control in a single spray.

Timing is everything.

Sprays must be applied anytime fresh bug populations arise and begin to increase because soapy water kills insects by coming into contact with them. When there are no insects around, spraying soap directly on the leaves has no effect because soap doesn’t bother insects if they consume it. If it touches the entire body, it will only function.

Can a plant thrips recover?

Thankfully, your plant should recover unless the infestation spreads. Make sure to keep the diseased plant far from other plants to prevent the infestation from spreading through contact between its leaves. All you have to do is keep up the treatment, check on the plant daily, and remember to wipe the leaves down.

The best course of action in extreme situations, when the thrips have taken complete control, is to completely bag up the plant, seal it off so the thrips can’t escape, and discard it. Even while it is always terrible to lose a plant, it is better to do so than to let the infestation to grow.

How can thrips infest plants?

The majority of the time, thrips will enter your home on the leaves of indoor plants that have spent the summer outside or when you buy a new indoor plant.

Thrips may also accompany cut flowers or vegetables that you bring inside from the garden because they are a frequent garden pest.

The adults can fly, yet they are also quite little. This means that open doors and window screens could allow thrips to enter. Find out more about the origins of indoor plant pests here.

Which indoor plants are susceptible to thrips?

Thrips can originate from a variety of sources, such as:

  • If you’ve grown your plant outdoors to summer, they might have attacked it, and when you moved it inside thereafter, you might have carried thrips with you.
  • You might have brought home or acquired fresh houseplants with thrips hiding on them. Especially in the outset of the infestation, they are frequently quite difficult to see.
  • Aroids (including Monstera, Alocasia, ZZ Plant, and many more), palms, and Calathea are some of the houseplants that are most vulnerable to thrips.

What do you use as a thrips spray?

Certain flying insects have trouble locating plants when they are covered in mulch or mesh that reflects light. Reflective mulch can delay or lessen the degree to which young plants become plagued by winged aphids and adult leafhoppers, thrips, and whiteflies if the plants are initially pest-free and relatively tiny in relation to the surface area that is covered with reflective material. Reflective mulch can be substantially more successful than pesticides at preventing or delaying infection of small plants, making it worthwhile to apply it in flower and vegetable crops that are particularly susceptible to viruses spread by insects. Reflective mulch loses effectiveness as plants get bigger, necessitating the use of alternative management techniques. By the time the plant canopy covers more than about half of the soil surface, reflective mulch no longer serves to deter insects.

For synthetic reflective mulch or mesh, silver or gray work best, however white also works. Some living and organic mulches, such as buckwheat (Fagopyrum esculentum) and organic mulches like straw, may also deter pests, though the evidence for this is less clear. Aluminum-metalized polyethylene and silver-embossed polyethylene plastic films are examples of synthetics that are readily available in commerce. These can be used for more than one season if they are managed appropriately. A small garden may benefit from aluminum foil’s effectiveness, but it is expensive and difficult to reuse due to its fragility.

Application techniques for synthetic mulch include:

  • Plant seedlings via the mulch’s perforations.
  • Leave a short, mulch-free strip along the planting row and apply the mulch before the plants begin to emerge from the soil.
  • Lay a crop that is strong enough to raise the material as it develops over a lightweight material that allows light and air to pass through.

Mulch may help some crops grow better by boosting light levels, keeping soil warmer over night, suppressing weed development, and preserving soil moisture in addition to temporarily repelling some flying insects. Mulch may also be detrimental. It can make crops more vulnerable to root diseases, limit the use of overhead irrigation, and make it more challenging to determine whether you are maintaining the right level of soil moisture in a plant’s rooting zone. Because most recyclers won’t take plastics with soil on them, plastic mulch is often thrown away in landfills. Find out which tools and techniques are most likely to be effective in your circumstance.

In spite of the fact that thrips damage is unpleasant, gardens and landscapes shouldn’t typically employ insecticides to combat it. Usually, feeding harm is not noticed until after tissue has expanded and grown. Thus, the thrips that caused the harm are frequently gone by the time damage to developing fruit or bent terminals is recognized. No amount of insecticide will make damaged tissue look better; plants will stay damaged until their leaves fall off, the damage is clipped away, or fresh, spotless fruit is developed. Insecticides often do not kill thrips quickly enough to stop the spread of virus from thrips to plants where plant viruses are an issue. The best strategy to avoid contracting viruses spread by thrips is to employ row covers or other thrips control measures.

For greenhouse thrips and other plant-feeding insects, contact pesticides with no lingering residues can be useful. Because they do not leave poisonous residues that would kill natural enemies migrating in after their treatment, these products have relatively little negative influence on biological pest control and are low in toxicity to humans, pets, and pollinators. Contact insecticides include neem oil (Green Light Neem, Schultz Garden Safe Brand Neem Oil), azadirachtin (AzaMax, Safer Brand BioNeem), insecticidal soaps (Safer), narrow-range oil (Bonide Horticultural Oil, Monterey Horticultural Oil), and pyrethrins, which many products combine with piperonyl butoxide (Ace Flower & Vegetable Insect Spray, Garden Tech Worry Free Brand Concentrate). Contact sprays must be used to completely cover buds, shoot tips, and other vulnerable plant portions where thrips are prevalent if they are to be successful. When thrips or their damage is first noticed on plants that have previously sustained unacceptable damage, start treatment as soon as possible. As long as pest thrips and vulnerable plant parts are both present, repeat the application as needed, unless the product label specifies otherwise.

In general, Spinosad is more effective against thrips than the products mentioned above (Captain Jack’s Deadbug Brew, Green Light Lawn & Garden Spray with Spinosad 2, Monterey Garden Insect Spray). Spinosad has a shelf life of one week or more and travels translaminarly (short distances) into sprayed tissue to reach thrips feeding in protected plant portions. Horticultural oil can help the spray mixture remain more persistent in plant tissue. This insecticide is a byproduct of a naturally occurring bacterium’s fermentation, and some formulations can be used organically. Avoid spraying spinosad on plants that are in bloom since it can be hazardous to some natural enemies (such as predatory mites and syrphid fly larvae) and bees.

Systemic insecticides are transported to other plant parts after being absorbed by one plant portion (such as the roots). An efficient, systemic neonicotinoid pesticide can be applied via trunk spray or injection to provide control pretty quickly. Neonicotinoid application and pesticide effect are delayed more with soil drench or injection. The ability of neonicotinoids to control thrips varies. For instance, professional applicators have access to dinotefuran (Safari), which can effectively suppress thrips. Imidacloprid (Bayer Advanced Tree & Shrub Insect Control, Merit) frequently fails to effectively control thrips, and it is not typically advised for thrips.

Neonicotinoids affect natural enemies and pollinators in variable degrees depending on the product, the environment, the species, and the invertebrate’s life stage. Neonicotinoid pesticides can go to flowers where they may affect pollinators and natural enemies who consume nectar and pollen. Unless the product label specifies otherwise, postpone systemic pesticide treatment until after plants have finished their seasonal flowering. These other plants may also absorb some of the soil-applied insecticide if their roots are growing close to treated plants. When feasible, wait until after the adjacent plants have finished flowering before applying soil.

Use a soil application or trunk spray rather than injecting or implanting pesticide into trees wherever possible to prevent tree damage and the potential transmission of infections on contaminated instruments. Trees suffer damage when their trunks or roots are injected or implanted, and it is challenging to repeatedly apply insecticide at the right depth. When implanting or injecting multiple trees, take precautions to avoid the spread of pathogens on contaminated tools. Before beginning work on each new tree, thoroughly clean any plant sap off of any tools or equipment that penetrates trees and disinfect it with a disinfectant that has been approved for use (e.g., bleach). Avoid techniques that result in significant incisions, such as implants inserted into trunk holes. No more often than once a year should you implant or inject roots or trunks.

For decorative, non-food plants, systemic organophosphate acephate (Lilly Miller Ready-to-Use Systemic, Orthene) is an option. Don’t use it. Acephate has the potential to be extremely poisonous to pollinators and natural enemies, and it has the potential to increase spider mite populations, which could harm plants.

Avoid using foliar sprays of other organophosphate pesticides like pyrethroids, carbamates, or malathion (such as carbaryl*) (e.g., bifenthrin, cyfluthrin, fluvalinate, and permethrin). These substances can lead to spider mite outbreaks, are extremely poisonous to pollinators and natural adversaries, and are ineffective against the majority of thrips. These insecticides are being discovered in surface water and are having a negative impact on aquatic organisms that are not their intended targets because their use in landscapes and gardens can run or wash off into storm drains and contaminate municipal wastewater.

Although greenhouse thrips can infest a wide range of plant species, they are most commonly a problem for perennial evergreens with broad leaves. It mainly appears on fruit clusters, the underside of leaves, and other plant elements that touch one another. The adults of greenhouse thrips are rarely fliers and move slowly. People eat in groups, and populations typically start in a small area of the plant and spread gradually. Pruning off colonies can be successful if sensitive plants’ undersides are periodically inspected to enable early detection and eradication of new infestations.

By thoroughly applying contact sprays like horticultural oil, natural pyrethrins (with piperonyl butoxide), or insecticidal soaps on the underside of infected leaves, greenhouse thrips can be easily managed. Reapplications can be required. Remember that the environment contains natural enemies of greenhouse thrips (discussed above). Make a determination as to whether spraying is necessary and choose substances that are least hazardous to natural enemies.