Hibiscus, belonging to the genus Hibiscus, is a crowd-pleaser in the garden world with its vibrant, saucer-sized blooms and lush foliage.
Fast-growing plants, they belong to the mallow family and are largely made up of hardy species, including Rose of Sharon (Hibiscus syriacus), Rose Mallow (Hibiscus moscheutos) and the Swamp Hibiscus (roselle).
These hardy varieties can withstand frost, making them a good choice for colder regions, while tropical favorites like the hibiscus rosa-sinensis, often referred to as the Chinese hibiscus, thrive in full-sun environments.
Hibiscus flowers, or ‘roses,’ provide a kaleidoscope of color, ranging from white to pink to red, with the diameter of the blooms reaching up to 8 inches in some cultivars.
These plants are loved not only for their visual appeal but for their ability to attract hummingbirds and butterflies, adding a flutter of life to your outdoor oasis. You will also often find the leaves of the hibiscus trees filled with colorful, chirping birds, creating a joyous garden atmosphere.
These perennials require well-draining soil, full sun exposure and consistent moisture conditions throughout the growing season for optimum growth.
While they perform well in direct sunlight, they also appreciate a bit of shade in the afternoons, particularly in hotter climates. No hibiscus plants appreciate too much water, however, as this can lead to root rot or leaf spots.
Caring for hibiscus flowers, whether they are annuals or perennials, is relatively straightforward, provided that you pay attention to the plant’s basic needs. In this article, I’ll share everything you need to know on how to plant, grow, and care for Hibiscus by sharing with you my years of experience as a master gardener.
Botanical Name: Hibiscus spp.
Common Name: Hibiscus
Plant Type: Annual and perennial herbaceous plants
Hardiness Zones: 5 – 11 (USDA)
Sun Exposure: Full sun, partial shade
Soil Type: Moist, well-drained
Soil pH: Acidic, Neutral
Bloom Time: Summer, fall, and year-round in tropical climate
Flower Color: Various (including white, red, pink, yellow, orange)
Native Area: Asia, North America
Hibiscus Plant Care
Hibiscus plants need full sun and well-draining soil to produce their vibrant blooms. They are fast-growing plants, with some cultivars capable of reaching a diameter of several feet in a single growing season.
It’s critical to keep hibiscus plants well-watered, but avoid too much water as it can lead to leaf spots and attract pests like aphids, whiteflies, and Japanese beetles which feast on their foliage.
Prune plants in early spring to manage their height and clear away any plant debris that could harbor disease. Lastly, to bolster their blooming power, feed them with a high-potassium fertilizer to ensure they get essential nutrients.
Hibiscus plants thrive best when they are exposed to full sun. These fast-growing plants require at least six hours of sunlight every day to flower profusely, with the blooms wilting if left in the shade.
However, in hotter climates, some light afternoon shade can prevent the leaves from scorching. If you’re growing a hibiscus tree indoors, make sure to position it near a sunny window as lack of light can affect its flowering.
Remember, maintaining optimal light conditions is as crucial as providing well-draining soil and sufficient moisture to the hibiscus plants.
A critical factor to consider when growing hibiscus plants is the type of soil used. All members of the genus Hibiscus thrive in well-draining soil, rich in organic matter and nutrients.
If you are planting in a pot, ensure you have a good quality potting mix, possibly enhanced with a layer of mulch, to hold in moisture yet allow for optimal drainage. A slightly acidic to neutral pH is preferred for these fast-growing plants.
For cultivars that prefer swamp-like conditions, such as roselle, consistently damp soil is ideal, but without standing water which can result in root rot.
Hibiscus plants all have specific water requirements to ensure their bright, showy blooms. These charming shrubs prefer a steady supply of moisture but also need well-draining soil to prevent water-logging.
During the hot growing season, water them deeply to fully saturate the soil; however, always allow the top inch of soil to dry between watering to ensure adequate soil aeration.
Overly saturated soil can cause the lower leaves to turn yellow and promote the growth of fungus that can lead to leaf spots.
Bear in mind that potted hibiscus and small hibiscus trees may require more water than those planted in the garden due to the fast evaporation rate from the pot.
Temperature and Humidity
Hibiscus plants all have their own unique requirements when it comes to temperature and humidity.
Generally, these fast-growing plants thrive when they are exposed to temperatures between 60 and 90 degrees Fahrenheit (15-32 degrees Celcius) and appreciate a humidity level above 50%.
However, many hardy species of the genus Hibiscus, such as the hardy variety rose of Sharon, can tolerate lower temperatures and frost better than their tropical counterparts.
Despite this, they would still benefit from being grown nearest to a sunny window indoors during winter. In gardens, placement in full sun is optimal, as this increases the moisture content in the leaves and stems.
During hot summers, mulching around the base of the shrubs will help retain moisture and regulate soil temperature, which the hibiscus plants greatly prefer.
Hibiscus plants flourish with a balanced supply of nutrients, particularly potassium, throughout the growing season.
Hibiscus trees and shrubs alike will benefit from a well-rounded liquid fertilizer applied approximately once a month, preferably with an evenly distributed ratio of nitrogen, phosphorous, and potassium.
Be sure to water your plants well after applying fertilizer, as Hibiscus plants desire well-draining soil with consistent moisture. Too much water can reduce the concentration of nutrients.
Any deficiency in nutrients will manifest in the plant’s foliage as yellowing leaves or leaf spots, lower leaves falling off prematurely, or lacking in blooms, thus it is crucial to ensure they are adequately nourished.
Finally, just before the arrival of early spring, taper off the fertilization process to give the plants a period of rest.
Types of Hibiscus
Tropical Hibiscus (Hibiscus rosa-sinensis)
The Hibiscus rosa-sinensis, commonly known as the Chinese hibiscus, is a perennial herbaceous plant belonging to the genus Hibiscus. This species of fast-growing plants thrives in well-draining soil with good moisture.
With bright, glossy leaves and colorful blooms that can reach a diameter of up to six inches, they will indeed create a tropical look in any garden. As they need full sun, placing them in a sunny window if indoors, is a good choice.
Roselle Hibiscus (Hibiscus sabdariffa)
Roselle Hibiscus, Hibiscus sabdariffa, is an annual shrub that stands out for its striking red stems. Known for its hardy species nature, this type of hibiscus can withstand a range of soil conditions but prefers a well-draining soil enriched with nutrients like potassium.
During the growing season, its leaves often attract aphids and whiteflies which can lead to leaf spots. Regular pruning can help control these pests.
Rose Mallow (Hibiscus moscheutos)
The hardy Hibiscus moscheutos, more commonly known as Rose Mallow or Swamp Mallow, is a large shrub that loves the swampy environment.
Originating from wetlands and along the edges of rivers, Rose Mallow brings large, eye-catching blooms to the garden paired beautifully with its deep green foliage.
While it can tolerate some shade, it appreciates a sunny spot and well-drained soil. Its lower leaves often fall off early in spring to make way for new growth.
Scarlet Rose Mallow (Hibiscus coccineus)
The Hibiscus coccineus, often referred to as the Scarlet Rose Mallow, is an eye-popping addition to any garden.
This fast-growing plant is a hardy variety that is notably resistant to pests like Japanese beetles.
Its bold, scarlet blooms and dark green foliage not only complement each other but also attract hummingbirds and butterflies throughout the growing season.
Rose of Sharon (Hibiscus syriacus)
The Hibiscus syriacus, also known as Rose of Sharon, is a beautiful type of hibiscus known for its hardy nature and medium-sized, colorful blooms.
As well as being used as a decorative flower, the Rose of Sharon is also used widely in horticultural circles due to its resistance to disease and pests.
These hardy shrubs can survive frost and thrive in a wide range of soil conditions as long as they have good drainage and some sun.
How to Plant Hibiscus from Seed
Step 1: Choosing the Right Hibiscus Seed
There are several species of the Hibiscus genus to choose from for your garden.
Favorites include the tropical Hibiscus rosa-sinensis, also known as the Chinese hibiscus, and the hardy variety of Hibiscus syriacus, commonly known as rose of Sharon.
Hibiscus moscheutos, or the rose mallow, is a perennial herbaceous plant that can thrive in a swamp-like environment.
For a late-season burst of color, consider cultivars of Roselle, which produce brilliant hibiscus flowers. When selecting seeds, remember the diameter of the blooms, which can vary from small, delicate flowers to large, impressive displays.
Step 2: Seed Preparation and Germination
Begin the planting process in early spring. Soak the seeds in plenty of water for about an hour to soften the outer shell. This encourages a faster germination process.
Next, sow seeds in well-draining soil in a pot or a nursery bed. The seedlings will need lots of light so place your pot on a sunny window sill or in a full sun location in your garden to ensure they get the light they need.
Step 3: Transplanting Seedlings
Once the hibiscus seedlings are about 3 inches tall, with well-developed leaves and stems, they can be transplanted to their final location. This location should ideally offer full sun with some shade during the hottest part of the day.
For soil, pick a well-draining variety that is rich in nutrients. Hibiscus plants, being fast-growing plants, require potassium and other vital elements for their growth and maintenance.
Step 4: Long-Term Care and Maintenance
Regular care of your hibiscus plants helps maintain their health and vigor. Regularly check plants for pests such as aphids, whiteflies, and Japanese beetles, which tend to feed on the leaves and can cause leaf spots.
Remove any plant debris from the base of the plant to prevent the occurrence of diseases.
As with all blooming shrubs, the hibiscus will benefit from pruning to encourage bushier growth and more blooms. Prune plants back in the early spring before new growth starts. Also, be careful not to give your hibiscus too much water; they need moisture but should never be sitting in water.
Finally, apply a layer of mulch around the base of the hibiscus plant. This will not only deter weeds but will also help to conserve moisture, especially during the peak growing season.
How to Propagate Hibiscus
Step 1: Choosing the Right Hibiscus
The best hibiscus to propagate are perennial herbaceous plants such as the hardy variety Hibiscus moscheutos, also known as rose mallow, and Hibiscus syriacus, or Rose of Sharon.
These plants are robust shrubs that can thrive in various conditions. You can also choose from different cultivars of hibiscus rosa-sinensis, often referred to as the Chinese hibiscus, for a flower that can brighten any sunny window.
Step 2: Planting the Hibiscus
The hibiscus plant thrives in well-draining soil. Ensure that your pot is filled with this type of soil, rich in nutrients and potassium, essential for the hardy species’ growth. Hibiscus plants prefer full sun but can tolerate a little shade.
Place the pot in a spot that receives abundant sunlight, preferably near a sunny window for indoor plants.
Step 3: Regular Care and Maintenance
Throughout the growing season, monitor the hibiscus plants and water them to maintain a consistent level of moisture in the soil. Too much water, however, can lead to leaf spots.
Spread a layer of mulch around the base to hold in moisture and prevent weeds. Fast-growing plants such as these will need to be pruned regularly and the plant debris cleared away to prevent it from becoming a breeding ground for pests.
Step 4: Preparing for the Blooming Season
Prepare for the blooms in early spring by giving the lower leaves a good prune to allow light to reach the center. This improves the foliage overall, encouraging the hibiscus flowers to bloom all over the plant.
These blooms are a hummingbirds’ and butterflies’ paradise, providing food while adding a vibrant color display to your garden.
Step 5: Protecting the Plant From Frost
Though hibiscus is a hardy species, frost can harm the plant. As the diameter of the cold season expands, protect your hibiscus by bringing it indoors or covering the shrubs with a frost cover or blanket.
If the plant gets damaged by frost, remove the affected stems and leaves to allow for new growth.
Step 6: Propagating the Hibiscus
Propagation is the final step in growing hibiscus. Encourage the growth of new plants by cutting a healthy piece of stem, and then planting it in a pot with well-draining soil.
Water the cutting well and place it in full sun or partial shade. Given the right conditions, you should soon see a new hibiscus plant start to grow.
How to Pot or Re-Pot Hibiscus
Step 1: Selecting the Right Pot and Soil
The first step to successful hibiscus care involves selecting the correct pot with a good diameter and ensuring it contains well-draining soil.
These fast-growing plants, belonging to the genus Hibiscus, can quickly become root-bound. The pot should be sizable but no more than 2-3 inches larger in diameter than the existing root mass.
The soil should be nutrient-rich and able to retain adequate moisture without causing waterlogged conditions, as no hibiscus enjoys having much water restricting their roots.
Step 2: Planting the Hibiscus
Upon correctly preparing your pot, make a hole in the soil that is approximately the same size as the root ball of the hibiscus.
Take care to ensure that the root system of the hibiscus plant becomes level with the soil surface once placed in the hole. Firmly pat the soil around the base, taking care not to damage stems, lower leaves, or blooms.
Step 3: Positioning the Hibiscus
Hibiscus plants thrive in full sun. However, certain cultivars may appreciate a bit of shade in the heat of the afternoon.
Place your hibiscus near a sunny window if you’re growing indoors. If you’re planting outdoors, select a spot in your garden that receives plenty of sunlight throughout the day.
Step 4: Providing Proper Care
After planting, be vigilant about protecting your hibiscus from frost during the cooler months. Even the hardy varieties should be moved indoors or covered during frost.
An application of mulch around the base of outdoor hibiscus plants can help retain soil moisture and warmth.
Common Pests and Plant Diseases for hibiscus
These small, soft-bodied insects can be a common problem for hibiscus plants. Aphids suck the sap from the lower leaves and stems, causing a lack of nutrients and potentially damaging the plant’s overall health.
They also produce a sticky substance known as honeydew which can lead to the development of sooty mold.
Japanese beetles are known to favor the genus Hibiscus, including Hibiscus syriacus (Rose of Sharon) and Hibiscus rosa-sinensis (Chinese hibiscus).
They chew on the leaves and blooms, leaving behind skeletonized foliage and flowers. Early detection and removal are essential to protect these fast-growing plants.
These small, white insects are found on the underside of leaves and can affect all types of hibiscus, including the hardy variety hibiscus moscheutos (Rose Mallow) and tropical cultivars.
Infestation can result in yellowing of the leaves, reduced growth, and a decrease in the plant’s vigor. Whiteflies can also transmit several plant diseases.
Leaf spots, caused by various types of fungus, can affect hibiscus plants, causing discolored patches on the leaves. If left untreated, leaf spots can ultimately lead to defoliation.
Regular removal of plant debris and maintaining good air circulation around plants can help prevent this disease.
While hibiscus are generally hardy species, frost can cause severe damage, particularly to tropical hibiscus like roselle and hibiscus rosa-sinensis.
It can lead to browning of foliage and eventually the death of the plant if it’s not protected or brought indoors during frost conditions.
Common Problems and Solutions for Hibiscus
Brown Tips on Leaves
Brown tips on the leaves of hibiscus plants often suggest that the plant is receiving too much water or not enough moisture.
Hibiscus prefers well-draining soil and should be watered thoroughly, then allowed to dry out before being watered again. Poor drainage can lead to root rot, so ensure your pot or garden area provides adequate drainage.
Yellowing of lower leaves may be an indication of a potassium deficiency or an overwatered plant. Providing additional organic soil rich in required nutrients like potassium or adjusting watering practices should help restore the leaves.
For hibiscus plants grown in pots, ensure they are placed by a sunny window or in full sun.
If your hibiscus flowers or buds are falling before they bloom, the plant may be stressed from fluctuating temperature, extreme temperatures, or insufficient light.
Hibiscus prefers full sun and warm temperatures for optimal bloom. In frosts, protect your plant or move it indoors if possible.
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Melissa Pino is a biologist, master gardener, and regular contributor for Planet Natural. Melissa’s work focuses on promoting environmentally-friendly practices, helping people create healthy gardens and finding ways to achieve overall health and wellness.