This article was written for Australian readers but will be of interest to gardeners in other parts of the tropical world where roselle plants are grown (‘rosella’ is an Australian local name for roselle). Note that ‘Top End’ refers to the northern part of the Northern Territory of Australia that is within the wet tropics. The ‘bush’ is an Australian term meaning wilderness areas and ‘bush tucker’ refers to food gathered from native plants. Darwin is the tropical capital of the Northern Territory.
Rosella is a well-known feature of the Top End bush lands or disturbed areas and is eagerly collected when the long stems crowded with bright red fruit appear in the early Dry season. Long famed as the source of a delicious tart jam that rivals marmalade, this is only one of the many great features of this naturalized plant species.
Rosella (Hibiscus sabdariffa) is thought to have originated in India and Sri Lanka and was widely spread by early visitors to our shores. Aboriginal peoples also aided its spread until now it is widely naturalized across tropical and sub-tropical Australia.
The plant is an annual in the wild, emerging from seed with the first rains and growing rapidly through the Wet. As the days shorten, they come into flower with large pale lemon, hibiscus-like blooms with a prominent dark ‘eye’ at the centre of the flower. Striking red fleshy calyces enclosing a globular seed capsule quickly follow.
It is these fleshy calyces that are used to make rosella jam, syrup, cordial and when dried the so-called red hibiscus tea.
However, it is not only this part of the plant that is useful. Grown in the garden, rosella plants develop large succulent leaves. When young, these may be chopped and added to salads to give a delicious sour flavor. Leaves may also be made into chutneys, both fresh and cooked, which make an excellent accompaniment to lamb or other fatty meats.
The flowers can also be used to make a pale-yellow syrup or jelly, but of course, this is at the expense of the delicious red fruit.
Grown in the garden rosella can achieve the status of a short-lived perennial plant. After harvest if the plant is pruned by about half and lightly fertilized and watered, new growth and several extra flushes of fruit will follow.
The wild rosella is a well-known and highly prized fruit, but it is about to be over shadowed by a new development from Darwin.
Some years ago, a new tetraploid variety appeared in a local garden.
This plant is simply sensational!
Unlike the wild (diploid) species, the new rosella differs in every possible way:
- The fruit is huge, often 3 or 4 times the size of the wild fruit.
- It is such a dark red colour that it is almost black.
- It is produced in far greater quantities on a dense leafy bush that is often wider than it is tall.
- In fact, branches may need support to carry the enormous weight of fruit carried or they can break under the load.
- The leaves are larger, thicker and a much darker green than the species.
- Fruit are sweeter and have less fibre than the wild fruits.
- From personal experience, I found that you will need 1.5 cups of sugar per cup of cooked pulp, but with the new variety, 0.5 cup of sugar per cup of pulp is sufficient.
- The resultant jam is far deeper in colour, rivaling the darkest red plum jam.
The plant is a willing perennial and can last up to three years, with almost continual fruiting, providing a light pruning and fertilizing follows each harvest.
The only drawback I have seen so far is that it is prone to mealy bug attack, which is rapidly spread by green ants, unless they are controlled at first onset.
Unless rigorously controlled, mealy bug can infest the fruit, making it unusable and severe attacks can kill the plant quite quickly.
As well as being a wonderful bush tucker plant, rosella can be an asset to any garden.