How do you spot thrips on houseplants?

Look for pale, silvery streaks on the leaves, often on new growth or flowers, dotted with tiny black specks. Those specks are thrips droppings. To confirm, tap a leaf or flower over white paper and watch for slender insects that run or jump. Thrips often arrive on new plants, so check recent additions first and keep the affected plant away from the rest.

Updated 12 October 2026

What does thrips damage look like?

Thrips damage starts as pale flecks that join into silvery streaks. The Royal Horticultural Society (RHS) says leaves often turn dull green, then silvery-white on the upper surface, marked with many tiny black excrement spots that look like small dollops of dark varnish.

The University of Maryland Extension describes the droppings as small, dark, tar-like spots glued to the plant near the damage. Young leaves that are still expanding when thrips feed can stay stunted, crinkled or curled for good. On flowers, petals become streaked or distorted, according to the University of Minnesota Extension.

How do you confirm it’s thrips?

Shake or tap a leaf or flower over white paper, as the University of California Statewide Integrated Pest Management Program (UC IPM) suggests. For flowers, South Dakota State University Extension adds a trick: blow gently into the bloom to make thrips move.

• Look closely with a hand lens. Maryland Extension describes slender, rice-shaped insects about 1 to 2 mm long that walk and can also jump.
• Hang a blue or yellow sticky card near the plant to catch flying adults, as Minnesota Extension suggests. It shows whether thrips are around.
• Make sure they’re there. UC IPM advises being certain pest thrips are present and causing damage before you act. By the time damage shows, the thrips may be gone.

Is it thrips, spider mites or something else?

If the marks match none of the rows in this table, Plant Doctor, an AI plant diagnosis app for iPhone, can suggest the most likely cause from three photos and show the evidence behind it.

What do thrips do to roses and other garden flowers?

Outdoors, thrips often hit flowers. Western flower thrips can damage roses, UC IPM says: petals may show dark streaks and spots from feeding before the buds opened, or buds may deform and fail to open. UC IPM adds that this thrips more often damages fragrant, light-colored or white roses.

Onion thrips feed on many plants, including dahlias, and the RHS notes that feeding at dahlia shoot tips can stunt growth and distort leaves. Since thrips hide in buds, you’ll often see the damage before you see the insects, UC IPM explains. Tap an open bloom over white paper to check.

How do thrips get into your home?

Often on another plant. Thrips travel on infested plants and float long distances on the wind, according to UC IPM. South Dakota State says plants that spent the summer outdoors can bring them in, and so can open windows, since thrips can crawl through a screen. Flowers and herbs cut from the garden are another way in, a University of Alaska Fairbanks horticulturist writes.

Minnesota Extension suggests isolating new plants for one to two weeks so any pest problems have time to show.

What should you do first about thrips?

Maryland Extension suggests starting without products:

• Trim disfigured leaves and any flowers with thrips tucked inside.
• Knock thrips off with a strong spray of plain water, both sides of the leaves. A sink works indoors; a garden hose works outdoors.

Don’t count on repotting. Repotting may remove pupae in the soil, Maryland Extension notes, but not the thrips on the plant.

If thrips persist, Maryland Extension names horticultural oil and insecticidal soap as less toxic choices. Indoors, use one labeled for houseplants. Outdoors, the label must cover that plant and that site. Follow the product label, and repeat as it directs; Maryland Extension warns that missed thrips reproduce quickly. Test a small area first, and go through the checks to make before you use any product.

Thrips are difficult to control, UC IPM warns. A heavily infested plant is best discarded, according to Maryland Extension, since that’s simpler and generally cheaper than treatment.

Will thrips-damaged leaves recover?

No. Leaves won’t regain their green color once it’s lost, even after the thrips are gone, the RHS says. Pesticides won’t restore injured plant parts either, UC IPM notes. Trim marked leaves if they bother you, and judge progress by clean new growth.

Thrips questions

The ASPCA lists some plants named on this page, such as Monstera and Schefflera, as toxic to dogs and cats. These notes are educational, not veterinary advice. If a pet has chewed a plant, call your vet or an animal poison control line. See which plants the ASPCA lists as toxic.