Ruby red rosella

Nov 20, 2022 | Gardening tips

Rosella (Hybiscus sabdariffa), known as Roselle in countries other than Australia, is not an Australian native as many people think but from West Africa. It is a bush that produces ruby red calyxes that make delicious jam or cordial, leaves that are used in tea making and salads, and an outer stem covering that can be stripped and used like jute. For the past 3 years I have been experimenting with growing Rosella. These are my tips for a successful crop.

Seed raising rosella

In Melbourne’s climate, it is best to raise rosella seeds in pots so that the plants are well established by the time the soil temperature has reached at least 20C. Plant 3 seeds per pot 1cm deep in seed raising mix, keep well watered, and later, thin out leaving the strongest. Sow seeds in mid-August. The seedlings will grow into bushes that can be as wide as 1.5m and as high as 2m.

Position, bed and water

In our climate, plant rosella seedlings in the hottest part of the garden in full sun, and preferably in a raised bed or wicking bed to keep the lower branches off the soil and out of reach of pests. Wicking beds are ideal as rosella is a plant requiring heavy watering (at least every 2-3 days if not in a wicking bed).

Soil and planting rosella

Rosella needs rich soil with plenty of compost and must be well drained. They are heavy feeders. When buds are forming, apply more compost. If planting in a garden bed, plants can be as far as 1m apart. In a raised bed, plant them 50cm apart. The branches will intersperse a bit like a hedge. You will need to plant 6-7 plants to get a good harvest.

Plant out rosella in mid – late October. Rosella needs a long summer – at least 6 months of hot sun – so there is little leeway for plants to mature if planted later than October. The calyxes develop as the days shorten. There are 2 flushes of calyxes – the first is sometimes light but the second will be heavy and occurs when the plant puts all its energy into reproducing before dying off. Technically, it is a perennial but treat it as an annual as cold weather and frost kill it.

Harvesting and preparing rosella

When the calyxes are 25 – 30 cm in diameter, they are ready to harvest. Use secateurs or sharp scissors to cut them, as the stems are quite thin and fragile. Store them in the fridge until you have enough to use. Inside the calyx is a seed pod that needs to be removed. It is quite big. Peel the petals of the calyx from the seed pod but keep the seed. There are many good recipes for jam and cordial on the internet.

Seed saving rosella

Either save the rosella seed when you prepare rosella for processing or leave some calyxes on the plants to dry just as you would with peas or broad beans. The seed comes out easily. Just tap the calyx on to your hand and it will fall out. Not all seed is equally viable so it is worth planting extra to ensure sufficient plants. Seeds are sold by Diggers, The Seed Collection, Eden Seeds and Seed Freaks in Tasmania.

Written by Robin Gale-Baker