Hoya curtisii problems — and how to fix them

The leading cause of decline. Soggy, poorly draining soil rots the fine roots and turns leaves yellow and mushy. Let the soil dry between waterings and use a fast-draining mix in a pot with drainage holes.

Too little light produces thin, sparse stems, small leaves and no blooms. Move it to bright indirect light with some gentle direct sun, and prune leggy stems to encourage bushier growth.

White, fuzzy mealybugs and scale hide in the dense foliage and leaf joints, sucking sap and weakening the plant. Isolate it and wipe or spray with diluted rubbing alcohol, insecticidal soap, or horticultural oil; repeat weekly until clear.

Tiny mites thrive in dry air, stippling and yellowing leaves and spinning fine webbing. Raise humidity, rinse the foliage, and treat with insecticidal soap or horticultural oil if an infestation takes hold.

Yellowing usually signals overwatering, but the succulent leaves can also shrivel from prolonged underwatering. Check the soil moisture and roots to tell which, then adjust the watering rhythm accordingly.

Water sitting on the compact foliage in still, humid air can cause fungal spotting. Water at the soil with a narrow-spout can, keep leaves dry, and ensure good airflow around the plant.