Hibiscus
In most of New Zealand, home gardeners growing hibiscus outdoors year-round are actually growing the hardy deciduous Hibiscus syriacus, often called Rose of Sharon, rather than the tropical Hibiscus rosa-sinensis of Pacific/Hawaiian imagery. Tropical hibiscus needs frost-free conditions and is usually only viable outdoors year-round in the warmest northern parts of the country; elsewhere it's typically grown in a container and moved under cover over winter. The hardy Rose of Sharon type wants full sun, moderate water, and flowers profusely through summer into autumn.
- Sun
- full sun
- Water
- moderate
- Spacing
- 150cm
- Difficulty
- intermediate
- Grows in
- Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson, Tasman, Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago, Invercargill / Southland
- Mature height
- 3m
- Flowering season
- Jan, Feb, Mar
- Attracts wildlife
- Bees
- Evergreen
- No, deciduous
- Common diseases
- Leaf spot
- Common pests
- Aphids, Scale insects
When to plant by region
In Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson and Tasman: September-November. In Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago and Invercargill / Southland: October-November.
Growing stages
Germination & planting
- Full sun brings the best flowering; choose a warm, open spot
- Confirm which type you're growing: hardy deciduous H. syriacus (Rose of Sharon) suits most NZ gardens outdoors, while tropical H. rosa-sinensis needs frost-free conditions or container growing
- Space plants around 150cm apart to allow for its mature shrub size
Establishment
- Water regularly while roots establish; moderate ongoing water needs once settled
- Watch new growth for aphids and scale insects
- Gardeners outside the warmest northern regions growing tropical hibiscus should keep it in a container that can move under cover over winter
Vegetative growth
- Continue watching for aphids and scale insects on soft new growth
- Leaf spot can appear in humid conditions; good airflow between plants helps
- Full sun and consistent moisture through the growing season support strong flowering later on
Flowering
- Flowers profusely from summer into autumn
- Bees visit the flowers; avoid spraying open blooms
- Deadhead spent flowers to keep the plant tidy and encourage further blooms
Dieback & dormancyWinter
- The hardy H. syriacus type is deciduous and drops its leaves over winter, resuming growth in spring
- Tropical H. rosa-sinensis grown in a container needs to come under cover before the first frosts
- Winter is a suitable time to shape or prune the hardy type while it's dormant