Short answer
Your ZZ plant is likely infested with spider mites, which thrive in the dry indoor environments this species prefers. The most effective fix is to isolate the plant, thoroughly rinse the foliage, and apply insecticidal soap or neem oil every 5-7 days for several weeks.
ZZ plants are remarkably hardy, but their preference for low humidity makes them susceptible to spider mites, especially if the air is stagnant. Fine webbing and speckled leaves indicate these pests are actively feeding on your plant's sap, which can cause long-term damage if left untreated.
Spider mites are tiny arachnids that pierce leaf cells to feed, resulting in tiny, pale spots known as stippling. They spin fine, silky webs between leaflets, which is a classic sign of an active colony on your ZZ plant.
Check: Wipe the underside of the leaves with a white paper towel; if you see small, rusty-colored streaks, those are crushed mites.
Fix: Isolate the plant, wash the entire plant under lukewarm water, and apply insecticidal soap or neem oil every 5-7 days for at least three weeks.
While ZZ plants tolerate low humidity, extremely dry indoor conditions can weaken the plant's cuticle and make it more vulnerable to pests. This stress often manifests as the plant struggling to maintain its moisture balance, which pests quickly exploit.
Check: Check the surrounding environment for heat sources like radiators or vents that may be causing localized dryness.
Fix: Move the plant away from direct drafts or heat sources and periodically wipe the leaves with a damp cloth to remove dust and discourage pest habitation.
Sometimes, what looks like spider mite damage is simply heavy dust buildup or physical scarring from handling. However, because you see webbing, you should always treat this as a pest issue rather than assuming it is just dust.
Check: If there is no movement and the spots do not wipe away, inspect the webs closely; if they do not contain small, moving dots, it could be common household dust.
Fix: Gently clean the leaves with a mixture of water and a drop of mild soap to restore the plant's ability to photosynthesize properly.
When to worry
You should act immediately upon seeing webbing, as spider mites reproduce rapidly in the dry, warm conditions that ZZ plants often inhabit, potentially causing widespread leaf drop.
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Diagnose my ZZ PlantNo, repotting is unnecessary and can actually stress the plant further. Focus on treating the leaves and stems with insecticidal soap instead.
Increasing humidity helps discourage mites, but it will not eliminate an existing infestation. Use a treatment like neem oil to kill the current population while maintaining slightly higher ambient humidity.
Yes, ZZ plants are very resilient and can recover well. As long as the rhizomes under the soil remain firm and healthy, the plant can regrow its foliage after the pests are eradicated.
Consistent with guidance from: University of Missouri Extension Houseplant Care Guide, Royal Horticultural Society Pest Management.