How to Grow Rosella

Also known as roselle or Jamaican sorrel, Rosella originates in Africa and is a member of the hibiscus family.

Although the fruit or calyx can be eaten fresh on its own or added to salads, rosella can also be used in cooking, jams, sauces, teas and medicinal treatments. Rosella jam is an Aussie favourite.

High in fibre, vitamin C, calcium and antioxidants, rosella has been associated with digestive aid, mild laxative effects, lowering blood pressure, boosting liver health, cancer prevention, weight loss, relieving menstrual pain, reducing inflammation, and more!

When to grow rosella

Rosella likes soil temperatures of 25-35°C (77–95°F) to germinate from seed and easily copes with temperatures beyond that. It also needs as long a season as possible, as it can take quite a while to grow. For this reason, starting the seeds in early spring (even if you have to do so indoors with heat mats) is ideal. If you are in quite a cool climate, you may need to grow it in a greenhouse to give it the warmth it craves.

Rosella varieties

There are over 100 varieties of rosella around the world with a variety of colours and sizes. In Australia we really only get a couple of different options:

· Rosella – the Australian classic that can be used in Thai cooking, salads as well as jams and teas

· Early Rosella – similar to the other variety, this variety will produce more fruit more quickly

How to grow rosella from seeds

Whilst you can direct sow rosella seeds, they often have a hit and miss germination rate which can be a pain when you are trying to maximise the use of your garden beds. For that reason, planting in seedling trays is ideal and the seedlings usually transplant well. Ensure you’ve got a good quality potting mix to start with as that will give your seedling the best possible start to life. Sow the seeds around 10mm (half an inch) deep and cover them over with soil before giving them a light water. Continue to water frequently to keep the soil moist but not wet. Seedlings will begin to emerge around 10-21 days after planting.

How to grow rosella from seedlings

Raised garden beds are perfect for growing rosella in – it ensures good drainage and will help prevent the long stems from flopping over and resting on the dirt where the fruit could rot and be eaten by bugs. Birdies garden beds are Mark’s raised beds of choice. To grow rosella from seedlings, you want to choose a location that gets full sun – these are heat loving plants!

Plant out each seedling 450mm or 18 inches apart for best results, as this will give the plant plenty of room to expand. If you are limited on space, the plants will still grow well if placed a bit closer together. Lightly water the seedling in with a seaweed solution such as the Plant Doctor’s Seaweed Secrets (use SSME10 for 10% off your order) to minimise transplant shock. Rosella is a fairly hardy plant so once established, it can survive getting a little dry, however it is best to water regularly.

How long does rosella take to grow?

Rosella will reach full maturity at around 180-200 days. Of course you may have calyxs appearing before that but this is definitely a plant that requires some time investment.

When to harvest rosella

As your calyxs grow, they will plump up – that is the ideal time to harvest them. This usually takes around 1-2 weeks from flowering. If you leave them longer, they may start to dry out a little and not taste as good.

Rosella pests and diseases and how to control them organically

Aphids

Aphids can be a gardener’s nightmare for a huge range of plants. These small insects can be found on the stems and undersides of leaves of your plant and can be a range of different colours depending on what they are eating. Left untreated, aphids can swell to proportions that risk your plant developing diseases and becoming unhealthy. The most natural way to avoid aphids is to attract beneficial insects such as ladybugs that eat the aphids. Other natural remedies include organic neem oil, diatomaceous earth sprinkled on top of the aphids to dehydrate and kill them, strong spray of water to dislodge the aphids, or a spray of soapy water which suffocates the aphids (be sure to hose off any soap later).

Cutworms

These caterpillars are mostly active at night and will chomp through the stems of your seedlings cutting off the top foliage at the soil level. You can head out to the garden at night with a torch

and pick off the cutworms one by one to help get rid of them, you can also sprinkle diatomaceous earth around your seedlings which will dehydrate the worms, you can create a “collar” to protect the seedling with toilet rolls/cardboard/paper, or you can even sprinkle cornmeal or coffee grounds around the base of the plants as the cutworms cannot digest it. Alternatively, BT (Bacillus thuringiensis) is a bacteria that kills caterpillars which can be sprayed on the plants (known as Yates Nature’s Way Caterpillar Killer/Dipel in Australia).

Powdery Mildew

If you find a powder-like substance on the leaves of your rosella plant, it is likely to be powdery mildew which is caused by a bacteria that loves hot, humid weather. The great news is that there are a few natural remedies that work well to stop the spread of it. Firstly, you want to water your plants at the base of the stem and avoid getting the leaves wet. Then you can try spraying the affected areas with a water and milk solution (1 part milk: 2-3 parts water), or mix 2-3 tablespoons of apple cider vinegar with a gallon or 4 litres of water and spray the affected leaves. There are other options including hydrogen peroxide, potassium bicarbonate, or copper too. Alternatively, you can use neem oil or another organic fungicide to treat it.

Mark’s top tips for growing rosella

Don’t get disheartened if your rosella plant produces a less than impressive flourish of calyxs. It may be tempting to rip out your plants afterwards and vow never to grow them again. Instead, be patient. Rosella likes to give you a little taste of what’s to come. After you’ve harvested the first flourish, wait because there will be a second, much more impressive flourish to come. You may also want to check out Mark’s video “5 tips how to grow a ton of rosella in one raised garden bed” for more tips.

Do you have any tips or questions about growing rosella? Mark and the Self Sufficient Me team love hearing about your growing success so why not join our forum to let us know how you went growing rosella?

If you had some trouble growing rosella or simply want to pick Mark’s brain about your self-sufficiency goals or projects, you may want to consider becoming a patreon for exclusive content and email access for less than a restaurant meal each month!