Plant care guide
Philodendron Spider Mites: Confirm, Rinse, Treat, Repeat
Updated
Why does my Philodendron have spider mites?
Fine pale speckling on philodendron leaves, a dull or faded look, and tiny moving dots or fine webbing on the undersides point to spider mites. They build up in dry indoor air, often in winter, and the damage usually shows before the mites do.
What to do first
Isolate the plant, confirm mites with a hand lens or a white-paper tap, then rinse every leaf underside with a forceful spray of water. Follow with insecticidal soap or horticultural oil labeled for houseplants, tested on one leaf first, and repeat weekly for several weeks.
Pale speckles spreading across a philodendron leaf are worrying, especially on a slow, prized plant. Spider mites are a known risk for the genus. NC State Extension lists them among the pests to monitor on philodendrons, and Clemson’s philodendron factsheet says that although philodendrons are generally pest-free, spider mites can infest them. The steps below apply to climbing and self-heading types alike.
Confirm it is spider mites
Clemson HGIC’s houseplant pests factsheet notes that mites are so small that damage is usually the first sign. Look for:
- Light speckling on the upper leaf surface and an overall faded look.
- Bronzing or yellowing as feeding continues.
- Silky webbing on the undersides and between leaf and stalk in heavier infestations.
- Tiny moving dots under the leaves. UC IPM says a 10× hand lens shows them easily (UC IPM: Spider Mites).
Colorado State Extension says early feeding shows as small patches of white flecks on the underside near the base of the veins (CSU: Managing Houseplant Pests).
UC IPM’s quick test: shake a leaf over white paper. Mites move once disturbed. Be sure they are present before you treat.
NC State also lists banded greenhouse thrips on philodendron. Clemson says thrips damage looks silvery or speckled, much like mite damage, but thrips move when you blow gently on the leaf. Webbing points to mites. See our philodendron thrips guide if you find slender insects instead.
Why philodendrons get them indoors
Iowa State Extension says many people first notice spider mites on houseplants in winter, when dry indoor air and slower growth favor them. Colorado State notes plants in hot, dry spots are prone to mites. UC IPM adds that water-stressed plants are especially susceptible.
NC State says philodendrons prefer high humidity but usually adapt to average homes. In very dry rooms it suggests a humidifier or a tray of pebbles and water.
What to do
- Isolate the plant. Clemson makes this the first step for any houseplant pest.
- Prune the worst leaves. Iowa State suggests removing heavily infested parts of larger plants before treating. Bag them.
- Rinse the foliage. Clemson advises spraying sturdy plants forcefully with water, including the undersides, to dislodge mites and break webs. Iowa State suggests the shower or bathtub. Support large leaves while you spray.
- Let the leaves dry. NC State notes that leaf spots on philodendron can be prevented by good air circulation and by keeping leaves from staying wet. After rinsing, give the plant good airflow so the leaves dry.
- Treat with soap or oil. UC IPM recommends insecticidal soap or oil, covering the undersides thoroughly. Colorado State rates horticultural oils as probably the most effective spray. Don’t treat water-stressed plants, or above 32 °C (90 °F), as UC IPM warns.
- Repeat weekly. Clemson says it is often necessary to spray once a week for several weeks.
UC IPM warns that some broad-spectrum insecticides make mite outbreaks worse. Iowa State advises against dish detergent in place of insecticidal soap, because some can harm plants.
Velvet-leaved philodendrons. We found no extension guidance specific to Philodendron gloriosum or other velvet-leaved species. Follow UC IPM’s advice and test any spray on one leaf a few days before treating the whole plant.
Handle it safely
The ASPCA lists philodendron as toxic to dogs, cats and horses because of insoluble calcium oxalates. NC State adds that the sap can irritate skin. Wear gloves when pruning.
Keep them away
- Raise humidity in dry rooms, as NC State suggests. Colorado State calls washing and increasing humidity the most effective controls.
- Water consistently, since UC IPM links water stress to more mite damage.
- Quarantine new plants for six weeks, checking leaf undersides weekly, as Clemson advises.
Damaged leaves keep their speckles. Judge success by new leaves that open clean. Our spider mites guide compares treatments across houseplants, and the philodendron hub lists our other philodendron pages.
Related guides
Other philodendron problems we cover: yellow leaves, nutrient deficiency, new leaf stuck in its sheath, toxicity to cats, dogs and people, brown leaf tips.
References
- NC State Extension Gardener Plant Toolbox: Philodendron
- Clemson Cooperative Extension: Philodendron, Pothos & Monstera
- Clemson Cooperative Extension HGIC 2252: Common Houseplant Insects & Related Pests
- UC Statewide IPM Program: Pest Notes: Spider Mites (Publication 7405)
- Colorado State University Extension: Managing Houseplant Pests
- Iowa State University Extension: Spider Mites on Houseplants
- ASPCA Animal Poison Control: Heartleaf Philodendron
How this guide was put together: NC State Extension, Clemson Cooperative Extension, UC Statewide IPM Program, Colorado State University Extension, Iowa State University Extension and ASPCA guidance.