Pests, webbing, and leaf spots on jade plant

How to tell

Small, brown, limpet-like bumps stuck to stems and the undersides of leaves, often with sticky honeydew.

The fix

Scrape them off gently with a fingernail or old toothbrush, then treat with a neem or horticultural-oil product made for houseplants, as its label directs, and keep checking. This plant is easily damaged by soap and oil sprays, so use a spray only if its label names Crassula. Test the spray on one leaf and wait two days before treating the whole plant, and skip any plant the label warns against.

How to get rid of scale →

How to tell

Fine webbing in the leaf joints, tiny moving dots, and a stippled, dusty look to the leaves. They thrive in the dry air many homes have.

The fix

Dab the leaves and stems clean with a damp cloth rather than rubbing them, give the plant good airflow, and treat with an insecticidal soap or neem product made for houseplants, repeating as its label directs until they are gone. This plant is easily damaged by soap and oil sprays, so use a spray only if its label names Crassula. Test the spray on one leaf and wait two days before treating the whole plant, and skip any plant the label warns against. Isolate it from other plants.

How to get rid of spider mites →

How to tell

Small black flies run across the soil and fly up when you water. Their larvae live in soil that stays damp.

The fix

Let the top layer of soil dry between waterings and catch adults on yellow sticky traps. A drier surface discourages egg laying and reduces egg and larval survival. If gnats persist, use a treatment labelled for fungus-gnat larvae on houseplants, following its instructions.

How to get rid of fungus gnats →

How to tell

Brown or black spots, often with a yellow halo, usually after the leaves stayed wet or the soil was overwatered.

The fix

Remove affected leaves, improve airflow, don’t leave water sitting on the leaves, and let the soil dry more between waterings.

How to tell

Dry, bleached, or brown patches only where strong direct sun hits the leaf, with no bugs or webbing. Jade plant wants bright light and some direct sun.

The fix

Shade it from the harshest midday sun for a few weeks, then let it back into the bright spot gradually.