Flower profile: hibiscus

The showy blooms of hibiscus take centre stage from late spring and continue to flower right through autumn. Each blossom lasts about 24 hours, with new ones flowering the next day. They may look delicate, but they’re tough! With warm weather and regular attention, they will add a ray of sunshine to your garden.

The show must go on!

Hibiscus flowers usually only last a day, but a new range of Hibiscus rosa-sinensis, ‘Flamenco’, has been bred specifically to produce large, long-lasting flowers, with some blooming for four to six days. Flamenco varieties have a compact, well-branched habit, and lush, dark green foliage. For stockists or to find out more, visit sprinthorticulture.com or call (02) 4385 4440.

Five of the best

Available in an amazing range of colours, sizes and shapes, you can buy a hibiscus in single, double and even miniature forms, with solid or variegated foliage. Check out these top species…

1. Tree hibiscus
This fast-growing evergreen tree, Hibiscus tiliaceus, has showy, lemon-coloured flowers with crimson centres, borne in splendid abundance during the summer months. It’s an ideal screen or windbreak for coastal landscapes, as it can tolerate full exposure to strong salt-laden winds.

2. Chinese hibiscus
The most familiar and widely grown variety of hibiscus, the Chinese hibiscus (H. rosa-sinensis) is associated with tropical holidays. It’s a lovely shrub to plant up, creating the feeling of a lush island paradise in your own garden. There are thousands of cultivars, so you’re spoilt for choice with the spectacular flowers available in almost every colour, and colour combination!

3. Coral hibiscus
The delicate, pinky-red blooms of Hibiscus schizopetalus are highly decorative. The eye-catching petals have exquisite frilled lobes, suspended from slender stems, so they resemble pretty hanging paper lanterns.

4. Rose of Sharon
This upright, cold-hardy deciduous shrub flowers freely in shades of white, pink, soft red, mauve and violet blue,
all with a crimson centre. Rose of Sharon (H. syriacus) grows to about 3.5m and the flowers, which can be single or double, are borne freely over summer. It’s the most frost-hardy of the genus, but suits a range of climates, from sub-tropical through to cool temperate, as long as it gets plenty of sunshine.

5. Confederate rose
A rose by any other name just might be a Confederate rose (H. mutabilis)! This rounded, deciduous shrub features blooms that open white and turn pink to rose-red as they age, so on any given day there will be white, pale pink and deeper pink flowers on the same shrub. The large, papery flowers also come in single and double forms, making it a gorgeous feature in the garden.

Dwarf hibiscus

Looking for a small hibiscus to keep on your verandah or patio? TradeWinds Breeze varieties grow up to 50cm, making them ideal for small to medium pots. This series has blooms in a range of colours including deep red, creamy white, tricolour orange and fluorescent pink. The vast majority appear in early spring to early autumn and will bloom continuously with minimal care. Available at your local Bunnings Warehouse.

How do I grow them?

Climate
Evergreen varieties of hibiscus will grow in tropical to warm-temperate climates, provided the area is free of frost. Deciduous forms, such as Hibiscus syriacus, will also grow in cool-temperate and frosty climates. Hibiscuses can be planted at any time of year, but it’s best to plant deciduous forms during autumn, so they have time to establish their roots before winter sets in.

Aspect
These gems are sun lovers, so plant in full sun and protect from strong winds.

Soil
Hibiscuses grow best in well-drained, slightly acidic (pH 6-6.5) soil. The one exception is H. syriacus, which is tolerant of alkaline soils. Before planting, ensure you improve the soil with well-rotted compost or manure. These plants also grow well in pots. Plant them up with an acidic potting mix such as Brunnings Azalea And Camellia Potting Mix or Osmocote Professional Rose, Gardenia, Azalea & Camellia Mix.

Water
During the growing season, water regularly, and ensure drainage is good. Mulch the surrounding area with organic mulch, straw, hay or sugarcane, ensuring it doesn’t touch the stem. This will help keep the roots cool and moist in summer.

Feed
These plants respond well to fertiliser. Choose one that encourages blooms, and is high in nitrogen and potassium, such as Yates Thrive Soluble Flower & Fruit Plant Food or Miracle-Gro MaxFeed Flowers & Blooms Soluble Plant Food. You can also add a fish emulsion or seaweed extract to this feeding mix. Apply before and throughout the growing season (August through to March) as this will help intensify bloom colour and promote healthy growth.

Pests
Check plants for the hibiscus flower beetle. These tiny black insects burrow their way through flower buds and foliage, leaving gaping holes. Use a systemic insecticide, such as Yates Confidor or Defender MaxGuard to control infestations.

Maintenance
The best time to prune evergreen types is at the start of the growing season or when the last frost has passed – usually in September. They flower on new season wood, as do the deciduous types, which should be pruned in winter. Prune just above a bud and remove any weak or dead branches. If left unpruned, hibiscus shrubs will become scraggy and shapeless, with fewer flowers and smaller, duller blooms. Prune off one-third of the plant to help rejuvenate tired-looking plants.

Floral imposter

Just because it looks like a hibiscus doesn’t mean it is! The native lilac hibiscus, Alyogyne huegelii, is not a true hibiscus, but is closely related. It has beautiful white or purple flowers that are borne on deeply lobed leaves. Like its relative, the blooms only last a day or two, however new flowers continue to open over a long period.

More info

If you want to know more about hibiscus and growing this wonderful plant, contact The Australian Hibiscus Society on (07) 3263 4232 or visit www.australianhibiscus.com