Roselle hibiscus is a beautiful, low-care plant that thrives in both garden beds and containers. It has attractive flowers and foliage, but it’s the calyxes which form after flowering that you’re after. The teardrop-shaped calyxes make a refreshing cold or hot tea with a tart, slightly fruity flavor. In this article you’ll find roselle hibiscus growing tips to help you enjoy the healthiest and most productive plants. 

Why you want roselle hibiscus growing in your garden

Also called Jamaican hibiscus, red zinger, sour tea, and Florida cranberry, roselle hibiscus (Hibiscus sabdariffa) is an edible shrubs in zones 8 to 11, but grown as an annual plant in cooler climates. It originates from Africa but is now enjoyed in many parts of the world. Like okra and sorrel, this plant is a member of the mallow family and the main reason to grow it is to harvest the cranberry red calyxes after blooming. These are the cup-like structures at the bottoms of the flowers. When brewed in hot water, the calyces make a refreshing tart tea that tastes of cranberries. Plus, it’s a lovely bright red color!

There are other reasons to want roselle hibiscus growing in your garden. The ornamental plants have dark red stems, attractive lobed leaves, and 3 inch diameter white to pale pink flowers with dark centers. They grow 2 to 3 feet tall and wide in my zone 6 garden, but in hot climates it can grow 6 to 7 feet or more. Like the calyxes, the leaves are also edible with a similar tart flavor and you can use them raw or cooked. I don’t pick the leaves, however, as I want the plants to grow large and yield as many calyxes as possible.

When to plant

Perhaps the most important piece of roselle hibiscus growing advice is to start the seeds indoors early as the plants need a long growing season to bloom and produce the calyxes. Sow the seeds 6-8 weeks before the last frost date, planting in soil blocks, cell packs, or 4 inch diameter pots filled with a high quality potting mix. Plant them a half inch deep and keep them in a warm spot to promote good germination. The ideal temperature range is 75 to 80 degrees F (24 to 27 degrees C) and I find it helpful to use a seedling heat mat to boost germination. Once the seeds sprout, turn off the mat. 

If you have more than one seedling in a soil cube, cell pack, or pot, thin to the strongest seedling once there are several sets of true leaves or divide and repot the extra plant. Keep the growing mix lightly damp and give the seedlings 16 hours of light each day using a grow light or a sunny window. When two sets of true leaves have developed, start to fertilize using a liquid organic fertilizer diluted to half strength. Repeat every two weeks. 

Harden off and transplant your roselle hibiscus seedlings outdoors when the soil temperatures are warm (at least 50 degrees F or 10 degrees C) and there is no longer a change of frosts. Gardeners in warm climates, zones 7 and up, can direct sow the seeds outside in early spring, but starting indoors still offers a head start. I’d also suggest planting in a spot with afternoon shade if you live where there are very hot summers.

Where to grow roselle hibiscus

This heat-loving plant thrives in full sun and fertile, well-drained soil. Add an inch or two of compost or manure prior to planting. I also work in a granular organic flower fertilizer to provide a steady supply of nutrients. Transplant seedlings 18 to 24 inches apart to give the plants room to grow. 

Any list of roselle hibiscus growing tips also needs to mention that this is a plant perfect for garden beds and pots. You can plant it in vegetable, herb, or flower gardens, or even tuck it between perennial plants. If you wish to plant in containers, select one that is at least 16 inches across. When you’re ready to transplant your seedlings, fill the container with a blend of high quality potting mix and compost. Also add an organic flower fertilizer. 

Roselle hibiscus growing tips

This tropical plant can be slow to grow, especially in cool climates. Help your seedlings size up with proper care. Here are a few tasks to keep in mind:

1. Pinching – This is an important step to promote branching and increase the yield of roselle hibiscus calyxes. When the plants are 10 inches tall, pinch out the growing tip, clipping back to just above a set of leaves. Use your fingers or a set of garden snips. 
2. Watering – Roselle plants have a deep root system that makes them drought resistant, but that doesn’t mean they doesn’t need to be watered from time to time. If the weather has been very hot and dry, deep water garden plants once a week. Roselle hibiscus growing in pots need to be watered more often. Gauge soil moisture levels by sticking a finger into the growing mix. If it’s dry two inches down, water. 
3. Fertilizing – I add a granular organic flower fertilizer at planting time to promote fast, healthy growth. I supplement this twice during the growing season with a dose of fish emulsion. The first is a month after transplanting and then a subsequent dose a month after that.

Roselle hibiscus growing problems

Roselle plants aren’t difficult to grow, but there are a few pests that can be an issue. These include insects like aphids and whiteflies which can cause minor damage. Check the plants periodically and use a jet of water from your hose to knock any pests from the plants. 

Harvesting roselle hibiscus

Many vegetables, like tomatoes and peppers, are harvested throughout the growing season. When you have roselle hibiscus growing in your garden you’ll have to wait until autumn to enjoy the harvest. This is because they’re short day plants. They don’t start to flower and produce calyxes until the days get shorter and there is more than 12 hours of darkness each night. 

Snap off the calyxes with your fingers or use garden snips to harvest. Slice off the bottom of each calyx and slip out and discard the seed pod. The fresh or dried calyxes are most often used for hot or iced teas, but other options for them include jams, cordials, and syrups. To make hibiscus tea, I use one tablespoon of dried leaves to one cup of water. I like to add other tea herbs, like lemon verbena, stevia or peppermint, to the pot. Or 4 to 5 fresh calyxes to one cup of water. 

To dry the calyxes to store for fall and winter, remove the seed pods and spread them on a screen or paper plate to dry completely for 5 to 7 days. Keep them in a warm, well-ventilated spot, but out of direct sun. Or, use a food dehydrator, a quick and easy way to dry the calyxes. Store the fully dried calyxes in jars in a dark cupboard to preserve their color. 

No article on roselle hibiscus growing tips should neglect to mention that the leaves of this plant are often used as a salad or cooked green. This happens most often in warm climates where the growing season is longer and the plants get larger. 

A final tip for roselle hibiscus growing

If you live in a climate where the seedpods have enough time to mature and dry during the growing season, harvest a few for seed saving. They can dry on the plant or, if the weather turns wet and cold, clip them and bring them indoors. When fully dry, remove the seeds from the pods and store them in envelopes or jars in a cool dry spot.

For more information on growing tea plants, be sure to check out these articles:

• How to grow and harvest lemongrass for tea
• Planting, growing, and harvesting chamomile
• Learn how to grow an herbal tea garden