How to Care for a Hibiscus Cairo Bush

Amend the soil in a sunny planting area with organic compost in a ratio of 1 part compost for each 4 parts of soil. Plant your Cairo hibiscus in spring, keeping the soil moist until new growth begins to appear.

Water your Cairo hibiscus once a week or every 10 days when it doesn't rain. Soak the ground thoroughly by running a hose at a medium drip for 30 minutes. Do not water when it rains because the roots can rot if they are constantly wet.

Prune your Cairo hibiscus in early spring when it first shows signs of vigorous new growth. This hibiscus, like most other varieties, will endure severe pruning, so if you need to control its size it won’t suffer if you cut it to several inches above the ground.

Fertilize your Cairo hibiscus beginning in early spring and repeat every two weeks until fall. Use a plant food with an N-P-K ratio of 20-5-20, following product instructions.

Check your plant for insect pests every week. Aphids and spider mites are common on hibiscus plants, as are Chinese rose beetles in areas where they occur, such as parts of Hawaii. Spray your plant with insecticidal soap if you need to control aphids or spider mites. Hang a 100-watt light bulb next to your plant at night if rose beetles are eating the leaves.