Hoya macrophylla problems — and how to fix them

The waxy leaf joints and undersides are a magnet for mealybugs, which show up as white cottony tufts and cause yellowing or curling leaves. Isolate the plant and wipe or spray with diluted rubbing alcohol or insecticidal soap/neem oil, repeating every few days.

Soggy, poorly draining mix leads to brown, mushy roots and a wilting, yellowing plant. Always let the top inch or two dry out, use a chunky epiphyte mix and a pot with drainage, and repot into fresh medium if roots have rotted.

The most common cause is insufficient light. Move it to brighter indirect light, keep it slightly pot-bound, and never cut off the bare flower spurs (peduncles), as new blooms form on the same spurs year after year.

Dry indoor air can invite spider mites, causing fine stippling, yellowing leaves and faint webbing. Rinse the foliage, raise humidity with good airflow, and treat with neem or horticultural oil until clear.

Even yellowing from the leaf centre outward often signals a nutrient shortfall in tired mix, while sudden drop usually points to overwatering, cold drafts or low light. Adjust watering, feeding and placement to match its needs.

Because the heavy waxy leaves sit close together, trapped moisture from misting or poor airflow can cause mould. Avoid misting, ensure good air circulation, and let foliage dry between waterings.