A guide to successfully pruning hibiscus plants.

The hibiscus is a beautiful flower. Many people are more familiar with the flamboyant Hawaiian hibiscus with its huge colourful flowers.

When it comes to hard-pruning hibiscus there are a few rules of thumb to which to adhere. For a vigorous grower, shorten it by at least half or more. But a delicate grower might only need to be cut back by about a third.

The first essential in pruning is a good clean cut and that means choosing an appropriate tool. For big branches use a lopper or saw. Don’t worry about pruning to an outward-facing bud because a hibiscus will make new growth from anywhere on the trunk. And remember a good clean cut is what you’re after, that helps to minimise disease risk.

In a Queensland’s warm climate we recommend hard pruning around September. But if you’re in a colder area delay pruning until you’re sure the last frost has gone. Pruning is done to promote new growth and if you prune in an area prone to frosts the new growth will be burned off.

Another time to prune is in February or just after that flush of flowers. Just prune back the bush by about 300 millimetres. Cut every branch back by that much to produce another flush of fabulous flowers in autumn.

Fertilise with hibiscus fertiliser or use a complete organic fertiliser. Look for one that’s fairly high in nitrogen and potassium and follow the directions on the bag. In Queensland we fertilise about a month before pruning, that’s in August so that the plant is ready to power away. In colder climates don’t fertilise until the first flush of growth after pruning.

Remember hard prune hibiscus in September and light prune in February and you’ll be well-rewarded with flowers.