By Penny Ossowski
This is a plant that you can grow anywhere in your garden, with its distinctive red stems, attractive light yellow flowers with deep red centres and open structure it is equally at home in the veggie patch, the ornamental garden or even in a pot and add to this that it can feed us as well, now is the time to add a couple to your garden.
The rosella, Hibiscus sabdarilla, is a member of the Malvaceae family of plants. Other well known members of this family include the ornamental hibiscus, cotton, cacao and okra. It is native to India and Malaysia but long ago was naturalised by many other tropical and sub tropical countries including Australia. Because of its popularity the rosella has many names some include roselle, Jamaican Tea, Maple-Leaf Hibiscus, Florida Cranberry, October Hibiscus, Red Sorrel and the list goes on. There are over 100 varieties of Hibiscus sabdarifla throughout the world. Not all varieties have red calyxes and not all calyxes are fleshy. Different varieties are grown for different purposes. In India a variety of rosella is cultivated for the bast fibre obtained from the stems, these fibre strands can be up to 1.5m long, are used to make yarn which is used in Hessian type fabrics, but primarily throughout the world the rosella is cultivated for culinary and medicinal purposes.
Rosellas will grow in almost any type of soil but do best in a well drained soil prepared with lots of organic matter and in full sun. They ideally need 5 or 6 months of
warm weather to produce to their full potential, making South East Queensland the ideal place to grow them. In cooler areas, plant as early as possible so they fruit early as frost will kill them. The rosella is a perennial but for optimum harvests it is grown as an annual. While usually grown from seed they can be grown from cuttings. Seeds can be planted directly into the garden or into seed trays, about 1/2 cm deep (seed trays in a warm protected position will give an earlier start to plants in cooler regions). It can help to soak seeds for about an hour before planting then water in with a mixture of 1 teas. Epsom Salts to five litres of water. Keep the soil moist until the seeds germinate. This is the time of the year to plant some rosella seeds. Plant out seedlings about 90cm apart when they have at least 4 leaves. Put in a Iittle blood and bone, soil conditioner or vermicast into the hole when you transplant them then water in with some Seaweed Spray. I usually give them a good watering with seaweed spray or fish emulsion a day or two before I transplant them.
The bushes should flower about 7 or 8 week after germinating, then it takes about another 3 or 4 weeks until the calyxes are ready to harvest. Water plants regularly until they start to flower then water only if necessary. Mature plants are fairly drought resistant. But if leaves droop give them a drink. The rosella bush will grow to between one and two meters tall. If you plant your seed early spring it is possible you can be harvesting in January or February. As the plant grows young shoots and leaves can be used both raw in salads or cooked like a spicy spinach in curries, stir fries or just as a green vegetable. Technically the calyxes are not a fruit but part of the flower and the seed pod inside should still be green when harvested. The most common and popular use for these tasty calyxes is to make Rosella Jam but they make a delicious tea, stew well for us in puddings, in jellies, heavenly liqueurs and syrups, cranberry like sauces and raw in salads. For use in teas it is usually better to dry the calyxes (they can easily be dried on a piece of old roofing iron) for later use but when collecting them for jams, jellies etc. clean them as they are harvested, dry then freeze them. In the West Indies the rosella calyxes are often made into cordials and punches as follows: pour hot water over about a kilo of dried Rosella with about one fresh grated ginger root added. Leave this to steep overnight. Strain off the exquisite pink liquid the next day and add sugar syrup (sugar and water heated) to taste, lime juice and crushed ice. White Rum can also be added for a famous medicinal rum punch. Each plant can produce up to 2 kg of calyxes. Pick them regularly and this will encourage more flowers and therefore more calyxes. In some African countries the seeds, although bitter, are ground and used like coffee or as a coarse powdered meal. Tea can be made with both the flowers and calyxes. Make an easy refreshing tea with calyxes, ginger and sugar.
Always save some seeds for next year's plants. From your early fruits select some good looking ones that can be allowed to mature for seed collection. I mark mine by tying a coloured ribbon on their stem so they are not accidentally harvested. When the seed pods inside are dry remove the calyxes (the calyxes can be used for eating cooking), open the pods to collect seeds. These seeds should remain viable for two or three years. I store mine in an airtight container in the bottom of the down stairs fridge.
The rosella bush has few pest and disease problems. Occasionally mealy bug and scale insects may be found on stems, caterpillars and beetles may eat leaves or calyxes and at times aphids can take up residence inside the calyx. Most of these problems can be solved with a soap spray or a molasses spray. If you have root node nematodes these can affect the rosella. Hibiscus beetles can sometimes be a problem. If they are they can be controlled by placing white ice cream containers with detergent and water among the plants, empty and replace with fresh water and detergent when necessary.
In many countries of the world all above ground parts of the rosella bush are used in traditional medicine.
Some of these include
- Infusions of the leaves or calyxes can be used for lowering blood pressure, as an antibacterial, as a remedy for the after effects of drunkenness
- It has been used as an antiseptic, aphrodisiac, astringent, cholagogue, demulcent, digestive, diuretic, emollient, purgative, refrigerant, resolvent, sedative, stomachic, and tonic.
- In East Africa, the calyx infusion, called "Sudan tea", is taken to relieve coughs and Roselle juice, with salt, pepper, asafetida and molasses, is taken as a remedy for biliousness.
- In Thailand, drunk as a tea, believed to also reduce cholesterol.
- Many Egyptians now use it to lower their blood pressure; an idea may be taken from folk medicine.
- The heated leaves are applied to cracks in the feet and on boils and ulcers to speed maturation.
- A lotion made from leaves is used on sores and wounds.
- The seeds are said to be diuretic and tonic in action and the brownish-yellow seed oil is claimed to heal sores on camels.
- Philippines use the bitter root as an aperitif and tonic.
- In folklore it is used as a remedy for abscesses, bilious conditions, cancer, cough, debility, dyspepsia, dysuria, fever, hangover, heart ailments, hypertension, neurosis, scurvy, and strangury.
Researchers now are doing studies to see if Rosella is indeed active in lowering blood pressure and cholesterol levels.
- Strip calyxes from Rosellas and rinse
- Put seeds in large pot, cover with water, bring to boil and boil for 1 hour, strain in muslin and squeeze very tightly (get all the gel liquid out of them), discard the seeds
- Add drained calyxes to liquid from seeds, bring to boil and boil for 1 hour
- Measure pulp (with liquid) and add sugar weight for weight (or cup for cup)
- Bring to boil and boil rapidly for 20 minutes while stirring
- Bottle into jars and seal
(This syrup will keep for at least a year. Once opened, it will keep for months if refrigerated. The syrup is delicious over crepes, fresh fruit, custard, ice cream. To make cordial, a very small quantity of syrup can be added to a glass and filled with water. The syrup can also be added to milk to make delicious drink.)
5 cups sugar 4 cups water 4 cups calyxes, chopped
Heat the sugar and water in a large saucepan until the sugar is completely dissolved. Add the calyxes and brine, bring to boil. Lower the heat and simmer gently until the volume of liquid is reduced a third. Remove from the heat and strain. Bottle the syrup while still hot into clean bottles and seal. The strained calyxes can be eaten as a desert with ice cream or custard.
To buy Australian Rosella seeds you can purchase online through Eden Seeds.