Tropical VS. Hardy Hibiscus

Bradford Greenhouses Blog

Hibiscus plants produce large, often tropical looking flowers in profusion, so it’s no wonder they are a popular plant in our gardens and patios. However there are many different kinds of hibiscus available, each having their own growing habits and requirements. This means to grow a hibiscus successfully you’ll want to put the right hibiscus in the right place.

Hibiscus is a genus in the mallow family of plants, and includes several hundred species. This has the result of many different plants sharing the common name of hibiscus. The key difference in hibiscus that are available here is between tropical species and hardy ones. Hardy species are ones that can tolerate the cold of our winters; tropical species cannot. It’s important to know which you are buying so you know what care it’ll require as well as avoiding disappointment if you happen to plant a tropical hibiscus in the ground expecting it to survive the winter.

There are many different varieties of hibiscus that are commercially available; and each have their own benefits. The three most common species you’ll encounter here are tropical hibiscus (usually Hibiscus rosa sinensis), hardy hibiscus (Hibiscus moscheutos) and Rose of Sharon (Hibiscus syriacus).

Tropical Hibiscus (Hibiscus rosa sinensis)

Tropical Hibiscus come in an incredible range of colours and continuously produce large, tropical flowers in the summer sun. They make excellent patio plants! Note, they are not winter hardy in Canada, bring indoors for winter.

This favourite tropical species is widely cultivated and has been hybridized into countless colours. It’s not surprising this plant’s showy flowers have become emblematic of the tropics. These plants will produce an abundance of large, colourful flowers. Each flower lasts only a day or two, however the plant will continuously produce new flowers in good growing conditions. This plant likes a good well-draining potting soil and appreciates frequent watering; it doesn’t like to dry out completely. If placed in a full sun location it’ll reward you with continuous blooms. This species is also evergreen, keeping its leave right through the year. It will grow into a large shrub or small tree in the right conditions, however its size can be kept in check when planted in a container and pruned. Hardy to zones 9 and above, this species does not tolerate the cold.

These plants make fantastic patio and container plants and love to spend summer outdoors. However, when the colder nights of autumn come, tropical hibiscuses need to come indoors, as they will not tolerate frost. They can be kept on as a houseplant through the cold months and brought back outdoors when the danger of frost has passed in the spring.

If you wish to have a tropical hibiscus planted in your garden and you intend to take it indoors in the fall, it is best to dig a whole and place the hibiscus, pot and all in the ground. This makes it easier both for you and the plant come autumn. If you plant it directly in the ground, it’ll grow long roots which you will unavoidably damage when it is dug up in the fall. That kind of traumatic transplant, coupled with the less than ideal growing conditions indoors would likely result in the death of the plant. Containers are the way to go if you intend to keep your tropical hibiscus long term.

Winter Hardy Hibiscus

These winter hardy species can be planted outdoors in your garden; as they will survive our winters. These plants are valued for their late season flowers that bring much needed colour to the late summer and autumn garden.

Hardy Hibiscus (Hibiscus moscheutos)

Luna Hibiscus

This ‘Luna’ hibiscus will produce a profusion of large flowers through late summer. Hardy zones 4-9.

Hardy hibiscus is a herbaceous perennial; each year it will send up new stems and will die back to the ground in winter. It will send up several large, branching stems that will produce large, round flowers in late summer in autumn. This native species to eastern North America has been cultivated and hybridized into many forms and colours. There are many different varieties available, ranging in heights from 2-4 feet and in a several colours ranging from white, pink to deep red including many bicolours. The foliage is highly variable in shape and colour, some forms have a coppery leaf colouring.

The key to success with this plant is providing it a sunny site with consistent moisture and good drainage. This plant does not like to dry out completely. It’s best to keep this plant well watered for the first two months after planting to help it get established. This plant is also late to emerge in spring, so don’t fear if you don’t see any new shoots forming before late May. Once established this plant is relatively care free and will lend a tropical touch to your garden with its huge, showy blooms.

Rose of Sharon (Hibiscus syriacus)

Hibiscus_syriacus_Blue_bird

This ‘Blue Bird’ Rose of Sharon produces striking purple-blue flowers. Winter hardy zones 5-9.

Rose of Sharon is the only hibiscus that is both cold hardy and a woody shrub. It can grow up to 15 feet tall if left unpruned. Pruning however encourages branching, which will result in a fuller shrub. Rose of Sharon will produce many flowers throughout the summer. Many varieties are available including single and double flowers, and ranging in colours from white, pink, purple to a near blue. Many varieties are bicolours as well. These plants do best in a sunny site with moist, but well-draining soil. Mature shrubs will have an overall vase shape.

This plant is highly valued for its large, showy flowers and ease of care. It makes a great specimen plant, or a nice informal hedge. It can add a touch of tropics to your garden with none of the fuss of a tropical hibiscus. Rose of Sharon makes an easy addition to the garden and will reward you year after year with spectacular blooms.

Rose Of Sharon Helene

Rose of Sharon ‘Helene’.

With so many varieties of hibiscus available there is sure to be one that’ll fit nicely into your yard or patio. Give one of these varieties a try; they’ll reward you for your efforts. Just be sure to put the right hibiscus in the right place, because regrettably, no amount of burlap will save a tropical hibiscus from our winters.