If you're looking for a plant with an impressive, exotic, trumpet-like flower in a wide range of colors and sizes, you can't go wrong with a Hibiscus—there are over 200 species and many more cultivars and hybrids in the genus.
Tropical hibiscus varieties (Hibiscus rosa-sinensis) are perfect if you live in a hot region or want an impressive houseplant. For those living in cooler parts of North America, opting for a hardy variety or the shrubby rose of Sharon (Hibiscus syriacus), which are both easier to grow and can withstand colder winter temperatures, will be the better choice.
While all hibiscus have similarities that go beyond appearance, they have some distinct care and growing requirements.
|Botanical Name||Hibiscus spp.|
|Plant Type||Annual and perennial herbaceous plants|
|Mature Size||3-10 ft. tall and 2-8 ft. wide|
|Sun Exposure||Full sun, partial shade|
|Soil Type||Moist, well-drained|
|Soil pH||Acidic, Neutral|
|Bloom Time||Summer, fall, and year-round in tropical climes|
|Flower Color||Various, including white, red, pink, yellow, orange|
|Hardiness Zones||5-11 (USDA)|
|Native Area||Asia, North America|
The care you provide your hibiscus will vary depending on whether it is a hardy or tropical variety and whether it is grown indoors or out.
You can grow most species of hibiscus without worrying about them getting out of control. However, rose of Sharon (Hibiscus syriacus) is classified as an invasive species in much of eastern North America.
Hibiscus love bright conditions. In northern climes, full sun is often best, but in the intense, dry heat of the south, filtered sunlight is better. If you find that your plant isn't producing many blooms, you can then try moving it to a sunnier spot.
Indoor tropical hibiscus will need a bright spot near a sunny window but out of strong sunlight. If you are transferring them outdoors when the warmer weather arrives, gradually acclimate them to the brighter conditions.
All hibiscus do best in well-drained, fertile, moist, loamy soil. The hardy varieties are wetland natives and are a good choice for sites that are too wet for other plants.
Most prefer a slightly acidic soil pH, but the rose of Sharon is tolerant of alkaline conditions. The color of hibiscus flowers can be affected by the acidity level.
Mulching around the plant base can help with moisture retention if you are experiencing dry weather. If you have nutrient-poor soil, amending with organic matter will be beneficial.
All hibiscus are thirsty plants that need to be kept moist. Indoor tropical hibiscus benefit from regular watering from spring to early autumn while the plant is growing. Significantly reduce watering outside this period. Ensure the top inch or so of potting mix dries out fully before watering—saturated soil is also problematic. Decent drainage holes in any pots are also vital.
Depending on the conditions, you may need to water your hibiscus daily to help it produce many impressive blooms.
If your hardy hibiscus are not planted beside a pond or in another wet area, they should also receive regular watering.
Temperature and Humidity
Rose of Sharon and hardy hibiscus can grow in cool, temperate climates. They thrive in temperatures from 60 to 90 degrees Fahrenheit but can handle temperatures as low as 20 degrees. When temperatures drop below 30 degrees Fahrenheit and frost is a risk, bring them indoors. Just be mindful of their higher humidity requirements—this is why bathrooms are a good location for these plants.
Temperatures below 50 degrees Fahrenheit can kill off tropical varieties, so they are best housed in humid locations indoors in regions where this is likely.
To encourage abundant, healthy blooms with good color, feed a high potassium and nitrogen fertilizer. Fish emulsion or seaweed extract are common organic additions. Feed a half-strength solution just before the start of the bloom period and continue at least once every few weeks until the end of flowering.
Types of Hibiscus
There are hundreds of tropical and hardy hibiscus hybrids and cultivars available. Just a few popular varieties include:
- Swamp Hibiscus (Hibiscus coccineus): An unusual, hardy species featuring large pinwheel-like flowers
- Confederate Rose (Hibiscus mutabilis): This hardy rose mallow has large, showy flowers that open white and then change color.
- Hibiscus rosa-sinensis 'Cajun Cocktail': A tropical cultivar with striking variegated blooms, giving each one a one-of-a-kind appearance.
- Hibiscus moscheutos 'Perfect Storm': A hardy, compact hybrid cultivar that blooms late in the season.
Hardy hibiscus benefit from annual winter pruning once they are established. Cutting the plant back after flowering, especially dead branches and old wood in the center can aid circulation and keep the plant looking tidy. Don't worry if you cut back aggressively; this species can handle it.
Most hibiscus propagation is from cuttings. Select a 4- to 6-inch piece from new, vigorous growth. Keep the leaves at the top growing section, but remove all the rest. You might want to dip the end in rooting hormone before potting in a well-drained, moist potting mix or soil. It can take a couple of months for the roots to take fully.
How to Grow Hibiscus From Seed
Growing hibiscus from seeds is more challenging than propagating from cuttings. They often take a long time to germinate and need a fair bit of attention.
Nicking the hard seed coating slightly and soaking the seeds for up to eight hours can speed up the process as it allows more moisture in. Warm, sunny conditions are best for success (at least 75 degrees Fahrenheit) and shallow sowing around a quarter-inch deep.
After a few weeks, the seedlings should appear. With their fragile stems, they will need careful translating and gradual hardening off too.
Potting and Repotting Hibiscus
Nutrient-loving potted hibiscus will benefit from being repotted every couple of years in early spring. Avoid deep pots, otherwise the plant will spend a lot of its energy on root development, and you want it to focus on flower production.
Hibiscus are not bothered by many pests or diseases, but red spider mites can be problematic when humidity levels are not high enough. Aphids are sometimes an issue too, but they can be kept at bay with regular cleaning or insecticidal soaps.
How to Get Hibiscus to Bloom
The exotic flowers on a hibiscus are short-lived, lasting from just one to 3 days. But if you have a healthy plant, they should produce many flowers through their growing season from late spring through fall annually.
Making sure your plant isn't too hot or cold is crucial to prevent flower drop. Frost is a problem, even for hardy varieties, and prolonged temperatures above 85 degrees Fahrenheit will cause flowering problems for even tropical hibiscus.
Deadheading isn't necessary, but if your plant is overly dry or not getting enough nutrients or sunlight, this can impact bloom productivity.
Common Problems With Hibiscus
Hibiscus are rather particular about conditions, and if you can't meet these, there are some common problems to watch out for.
If you see your plant's leaves turning yellow, it could be that you are subjecting it to sudden changes in weather conditions, getting the watering wrong, or not giving it enough nutrients. Expect a little yellowing during the transitional seasons of spring and fall, but anything extreme merits further investigation.
Dropping of Buds
Extremes in temperature, not enough light or humidity, and over or under watering can cause bud drop.
Are hibiscus easy to grow?
Hardy hibiscus are more forgiving and easy to grow than tropical varieties because they can handle a wider range of temperatures and wetter conditions.
How fast do hibiscus grow?
Hibiscus are fast-growing, and, providing conditions are right, they can be fully established and flowering prolifically within two to three years.
How long can a hibiscus live?
This depends greatly on the variety you have selected. New hybrids may not live more than a decade, but it isn't uncommon for older varieties to live over 50 years.