Troubleshooting
Cape jewels problems — and how to fix them
Cape jewels (Nemesia strumosa) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Heat-induced decline
Flowering stops abruptly and plants deteriorate when temperatures exceed 25°C for extended periods. Cut back by one-third, keep moist, and plants often re-flush when cooler weather returns in autumn.
Root rot (Pythium/Phytophthora)
Wilting in wet compost with blackened stem bases indicates root rot. Ensure excellent drainage, allow slight drying between waterings, and avoid cold, wet conditions at planting.
Aphids on shoot tips
Soft new growth is a magnet for aphid colonies. Check plants regularly; treat with insecticidal soap spray or neem oil at the first sign of infestation before colonies establish.
Prevent cape jewels problems before they start
Most cape jewels issues are care-mismatch, not bad luck. Dial in the basics:
Looking for cape jewels in general rather than its problems? Read the full cape jewels care guide — light, water, soil and feeding.
Cape jewels problems — FAQ
Why is my cape jewels heat-induced decline?
Flowering stops abruptly and plants deteriorate when temperatures exceed 25°C for extended periods. Cut back by one-third, keep moist, and plants often re-flush when cooler weather returns in autumn.
Why is my cape jewels root rot (pythium/phytophthora)?
Wilting in wet compost with blackened stem bases indicates root rot. Ensure excellent drainage, allow slight drying between waterings, and avoid cold, wet conditions at planting.
Why is my cape jewels aphids on shoot tips?
Soft new growth is a magnet for aphid colonies. Check plants regularly; treat with insecticidal soap spray or neem oil at the first sign of infestation before colonies establish.