Plant care guide
Can Spider Mites Kill a Rubber Plant? Signs and Treatment
Updated
Why does my Rubber plant have spider mites?
Yes, if they are left unchecked. Spider mites stipple rubber plant leaves with pale flecks, then turn them yellow or bronze until they drop, and Clemson Extension says an unchecked infestation can kill the plant. Colorado State Extension says repeated washing over several weeks should bring numbers down to low levels.
What to do first
Isolate the plant and wash both sides of every leaf with a damp cloth or a shower spray, weekly for several weeks. If mites persist, use a horticultural oil labelled for houseplants, tested on one leaf first, and keep the plant out of hot, dry spots.
Speckled, dull leaves on a rubber plant can make you fear the worst. Spider mites can kill a rubber plant if nothing is done, so act on the first signs. NC State Extension names spider mites, mealybugs and scale as pests that can be problematic on Ficus elastica.
How serious is it?
Clemson Extension’s houseplant pests factsheet describes the progression. Feeding causes light speckling on the upper leaf surface and a faded look. Unchecked, leaves turn bronzed or yellow, and the plant dies.
The RHS says heavily damaged plants can be severely weakened and may die. UC IPM says a generation can be completed in under a week when conditions suit them (UC IPM Pest Note 7405). That speed is why a few speckled leaves deserve action now.
Confirm it is spider mites
- Fine pale flecks. Colorado State Extension says damage starts as small patches of white flecks on the leaf underside near the base of the veins (CSU: Managing Houseplant Pests).
- Moving specks. UC IPM suggests shaking mites onto white paper. Under a 10X lens they are oval, with eight legs.
- Fine webbing on leaves and stems, which Clemson says appears with heavier infestations.
- Dry heat. Colorado State says plants in very hot, dry sites are prone to spider mites. UC IPM adds that water-stressed plants are highly susceptible.
The RHS lists glasshouse red spider mite, thrips, mealybugs and scale for Ficus elastica. Sticky leaves or immobile bumps point to scale or mealybugs instead; see our scale insects guide.
Rule out other causes of leaf loss
Clemson’s rubber plant factsheet says too little light, dry air or cold drafts can cause leaf loss, and soil that stays too wet yellows leaves. NC State adds that it is normal for some bottom leaves to yellow and drop. Without stippling or mites on the paper test, look at watering first; see rubber plant overwatering.
What to do
- Isolate the plant. Colorado State says mites crawl or are carried to nearby plants.
- Wash every leaf, both sides. NC State recommends a damp soft cloth or sponge for rubber plant leaves. Clemson’s rubber plant factsheet says to wash the leaves with water. A smaller plant can go in the shower; Colorado State says repeated washing with a jet of water over several weeks should reduce mites to low levels.
- Repeat weekly. Clemson says weekly sprays for several weeks are often needed.
- Use oil if washing is not enough. Colorado State rates horticultural oils as probably the most effective spray, and insecticidal soaps as marginally effective. Test on one leaf first and cover the undersides fully.
- Prune the worst leaves. Bag them straight away.
Fix the conditions
- Move it away from heaters and hot, sunny glass.
- Water evenly. Clemson advises watering thoroughly, then letting the mix dry slightly; UC IPM links drought stress to mite outbreaks.
- Raise humidity. Colorado State lists washing and increased humidity as the most effective controls.
Safety
Clemson says the sticky white sap may irritate skin, or the stomach if eaten. Wear gloves when pruning. The ASPCA lists Ficus species in its weeping fig entry as toxic to dogs, cats and horses. Keep pets away from cut leaves and wet sprays.
Prevent a return
- Wipe leaves regularly. Clemson says washing smooth-leaved plants every two to three weeks discourages pests.
- Check undersides in winter, when indoor air is driest.
- Quarantine new plants for six weeks, as Clemson suggests.
Our spider mites guide covers mite biology in depth. For curling rather than speckling, see rubber plant curling leaves, or return to the rubber plant hub.
References
- Clemson Cooperative Extension HGIC 2252: Common Houseplant Insects & Related Pests
- Clemson Cooperative Extension HGIC 1510: Rubber Plant
- NC State Extension Gardener Plant Toolbox: Ficus elastica
- RHS: Ficus elastica
- RHS: Glasshouse red spider mite
- Colorado State University Extension: Managing Houseplant Pests
- UC Statewide IPM Program: Pest Notes: Spider Mites (Publication 7405)
- ASPCA Animal Poison Control: Weeping Fig (Ficus sp.)
How this guide was put together: Clemson Cooperative Extension, NC State Extension, the RHS, Colorado State University Extension, UC Statewide IPM Program and ASPCA guidance.