Check Cactus assortment for webbing, white fluff, sticky residue, or spots. Identify pests and treat the cause safely.
Mealybugs. Dab each one with a cotton swab dipped in rubbing alcohol, then treat with a neem product made for houseplants, as its label directs. Test the spray on a small patch and wait two days before treating the whole plant, and skip any plant the label warns against. Check weekly: they hide.
Not a match? Compare the signs below to find the one you have.
How to tell
Small, brown or gray, limpet-like bumps stuck to the stems, 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. Test the spray on a small patch and wait two days before treating the whole plant, and skip any plant the label warns against.
How to tell
Fine webbing in the spines, tiny moving dots, and a stippled, dusty look to the stems. They thrive in the dry air many homes have.
The fix
Dab the 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. Test the spray on a small patch and wait two days before treating the whole plant, and skip any plant the label warns against. Isolate it from other plants.
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 of the soil dry out between waterings and catch the adults on yellow sticky traps. The larvae die off once the surface stays dry.
How to tell
Brown or black spots, often with a yellow halo, usually after the stems stayed wet or the soil was overwatered.
The fix
Remove affected tissue, improve airflow, don’t leave water sitting on the plant, and let the soil dry more between waterings.
How to tell
Bleached, yellow or brown patches only on the side that faces the sun, with no bugs or webbing. Cactus assortment 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.
Inspect new plants before bringing them home, check the stems and spines now and then, give it good airflow, and isolate anything infested. Keep pets away from a treated plant until the spray has dried.
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