Hibiscus rosa-sinensis

Common nameChinese hibiscus

Plant type Subtropicals, Shrubs

Plant Uses Hedging Plant, Container Plant, Border, Attract Beneficial Insects

Best uses

Best used as a specimen, in a tropical border or as an attractive hedge or screen. In cooler climates, they make an exceptional pot plant that can be placed outside during the summer months.

Physical characteristics

A large evergreen shrub that grows to 4m tall and 3m wide.

Flowers and foliage

Large single red flowers are produced through summer and into autumn. Foliage is dark green and toothed.

Preferred site

Prefers full sun and a sheltered site that is protected from frost and cold winds. Planting against a north wall in a raised bed is ideal to ensure soil is free-draining.

Preparation for planting

Always choose healthy, well-grown plants. An ideal spot to plant hibiscus is against a north wall in a raised bed to provide good drainage. Plant after autumn rains when the soil is moist and warm, allowing trees and shrubs to become established before winter. Planting success is often improved on clay soils by adding extra topsoil and forming raised beds. Incorporate coarse sand, bark and compost to improve soil structure. Before planting, ensure that the root ball is saturated and remove planter pot with minimal root disturbance. Trim any broken roots or branches and plant at the same level as in the container. Long term, slow-release fertilisers may be added at this stage. As soil is placed in the prepared hole, tread firmly to bring soil in close contact with the root ball. Water thoroughly, making sure that moisture penetrates to the depth of the root ball.

Maintenance tips

Mulch annually to help conserve moisture and suppress weeds. Pruning is important for established bushes during late September to October. Cut back hard if plants are looking leggy. To keep mature plants growing vigorously, prune out about 1/3 of the old wood in spring. Hibiscus respond well to the addition of general-purpose fertiliser applied through the growing season. Container-grown plants will require more frequent applications.

In warmer areas, hibiscus appreciate abundant watering and fertilisation when newly planted. They require little care once established. They can be trained into an informal hedge with secateurs by snipping off the tips of developing branches in spring and mid-summer. Since plants flower on new growth, this type of pruning will also increase flower production. Untimely pruning often removes flower buds.

Ecological and biodiversity benefits

Attracts butterflies.

Pests and diseases

If any branches suffer from pests or diseases prune infected branches out. Hibiscus can be plagued with aphids on new growth. Other potential problems are mealybugs, mites, scale and whiteflies especially if grown inside. Yellow leaves may be a sign of low nitrogen. Botrytis can also infect the flower buds and leaf spot can appear on the foliage. It is best to remove the damaged plant parts. Canker can also kill branches or entire plants.