Your Complete Hibiscus Care Guide

Your Complete Hibiscus Care Guide

Your Complete Hibiscus Care Guide
golden yellow hibiscus flowers with red center

Photos by Doreen Wynja

Hibiscus brings exotic flair and big color to the garden. Their showy flowers and glossy leaves are perfect for anyone looking to add a pop of color. This member of the mallow family (Malvaceae) has over 30 species native to North America. This consists of both woody and herbaceous plants. Some of the more well-known Hibiscus species grow in tropical climates. However, you can find many other species in colder regions of the U.S.—all the way down to Zone 4. Regardless of your location, you can find a hibiscus that will bring that bold, tropical style to your garden.

This complete hibiscus care guide covers everything you need to know about growing and caring for hibiscus. From fertilizing to watering, and even how to grow them in containers and indoors. But before we can begin with the care details, we need to outline the most common hibiscus types. Then you'll know what to look for to meet your needs in your specific garden. You'll find the top performers in each category to help with your next hibiscus hunt at your local garden center

Hibiscus Types and Favorite Varieties

Tropical Hibiscus 

Tropical Hibiscus (Hibiscus rosa-sinensis) is a medium-sized shrub that typically reaches 5' tall in the landscape. In warm climates (Zone 9-11), Tropical Hibiscus can be grown outside year-round, creating a tropical accent in the garden. They are effective as a hedge or a specimen planting. Regardless of their growing zone, many gardeners use them in containers for patios and courtyards. Growing them in containers allows the incredible flowers to stand out in the garden. (Get tips for growing them in containers further down).

Many growers train these shrubs into a tree shape, adding to their unique look.  They are a fantastic choice for adding bold color and a resort-like, tropical feel to an outdoor space. 

Tropical Hibiscus favorite: Jazzy Jewel® (Zones 9-11)

An excellent selection of tropical hibiscus that's exclusive to Monrovia. Jazzy Jewel® produces a prolific amount of large, bright flowers. The incredibly long-lasting blooms and dark-green foliage contrast to create an eye-catching combination. A beautiful way to add bold, exotic flair to a patio, balcony, or courtyard. Up to 5' tall and wide in the landscape where hardy (smaller when grown as an annual or in a container). Zones 9-11.  

Hardy Hibiscus

If you garden in a cold climate, consider growing hardy hibiscus for a return of bright, bold flowers each year. While the tropical hibiscus is a woody shrub, hardy Hibiscus grows as an herbaceous perennial. It dyes back to the ground each winter. This perennial hibiscus slowly emerges in spring but quickly grows to 4' tall in early summer. The plants reward your patience with clusters of massive blooms the size of dinner plates.

You can grow several species of hardy hibiscus in a wide range of zones. Still, the most common species is Hibiscus moscheutos, which is native to the central United States. To get the maximum effect of these plants, consider planting them as single specimens. Or, in small groups in a visible area of your landscape. You can plant spring-blooming bulbs around your Hibiscus to fill in the space until the plant comes out of dormancy. Once the bulbs bloom, the Hibiscus will emerge and cover up the bulb foliage. 

Hardy Hibiscus Favorite: Head Over Heels® (Zones 4-10)

This series of Hardy Hibiscus is stunning! These show-stopping plants feature shades of white, pink, and red flowers. All against a backdrop of burgundy foliage, making them ideal for cottage gardens and borders. Up to 2' tall, 4' wide. Zones 4-10.

Rose of Sharon

Better known as Rose of Sharon, this cold-hardy hibiscus (Hibiscus syriacus) is a shrub with a woody structure. It's perfect for Zones 5-9 and can grow up to 10' tall. Rose of Sharon is more tolerant of poor soils and drier conditions than other hibiscus types. It's the perfect option for gardens that don't have the ideal moist, rich soil that other hibiscus types love.

They're perfect for creating a privacy hedge. Or, as a large specimen shrub that can anchor a garden with its size and colorful flowers. It takes a while for Rose of Sharon to leaf out in spring. Patience is required, but the reward is well worth the wait. Rose of Sharon treats you to the showy blooms that hibiscus is known for. This makes this shrub stunning in a northern landscape.

Rose of Sharon Favorite: Chateau™ (Zones 5-9)

Breeders have created new varieties of this plant in recent years. Thus giving you more options for flower color and plant size. If you're looking for a Rose of Sharon with a big impact, consider the Chateau™ series. This is named after the Loire Valley in France. These enchanting plants are covered in showy flowers from top to bottom from early summer to fall. 

This exclusive Rose of Sharon series offers various flower colors, including Chateau™ de Versailles, featuring blue-violet blooms. You will also find varieties with shades of pink and purple flowers (see them below). Up to 6' tall and 4' wide. Zones 5-9.

How To Grow Hibiscus

white hibiscus flowers with red center

What conditions do Hibiscus plants need to thrive?

There are various hibiscus types, but each has similar requirements. Hibiscus are typically easy to grow. Although, like most plants, they do have conditions that they prefer in order to really thrive and look their best. An excellent way to determine proper site conditions is by looking at the native habitat of Hibiscus.  

Sunlight: Hardy Hibiscus is native to wet areas of the central and eastern United States. You can find them growing in marshes, flood plains, and moist woodlands. These conditions tell us hibiscus thrives in areas with full sun but will tolerate light shade. It’s best to avoid heavier shade, as the plants will lack vigor and flower less.  

Tropical Hibiscus is native to areas with warm year-round temperatures and full sun. This makes it critical to give them warm conditions. Doing so will promote healthy plants that produce an abundance of flowers.  

Soil: A crucial part of growing hibiscus. These plants prefer soil that stays consistently moist, but they can tolerate drier conditions once established. Ideally, they should receive fertile soil rich in organic matter. Healthy soil will retain water and nutrients, allowing your hibiscus to thrive. Worried that your soil isn't up to snuff? Opt for a Rose of Sharon, which is more tolerant of poor soils. 

Temperature: The requirements for temperature vary based on the type of hibiscus you're growing. As mentioned before, Hardy Hibiscus can be grown down to Zone 4 with protection. Some gardeners leave the old stems on the plant until spring, creating a layer of protection for the crown. Rose of Sharon is another hibiscus hardy to Zone 5. Just remember to give it time to leaf out. As it may be the last plant to break dormancy in your garden. 

Tropical Hibiscus has very different requirements for temperature. Gardeners in tropical climates may never experience freezing temperatures. At the same time, gardeners living in the colder areas of Zone 9 will have freezing temperatures occasionally. Unlike many tropical plants, Hibiscus will survive a freeze down to the mid 20s for a brief period. Temperatures below 20°F will likely kill the plant. If you live in Zone 9, consider using an extra layer of protection when a freeze is in the forecast. Try a thick layer of mulch around the base of the plant. Covering the Hibiscus with a sheet is also effective. 

Space: Proper spacing is critical for growing any plant. Tropical hibiscus grows up to 5' tall and wide in the landscape. This means you should space the plants about 5' apart when you plant them. Hardy hibiscus will reach 3-4' tall and wide, requiring you to space them 3-4' when planting them.  

Rose of Sharon can get much larger than Tropical and Hardy Hibiscus. Sometimes growing up to 8 ft wide, depending on the variety. Therefore, you should space them further apart compared to other hibiscus. However, some varieties of Rose of Sharon are shorter and compact. Always check the plant tag before planting.

Water: Hibiscus grows in wet habitats, making them valuable plants for landscapes with moist soil. They can thrive in drier soils, too (Rose of Sharon is especially tolerant of drier soils). Just be sure to keep them well-watered until they become established. Consider planting in late spring or early summer to establish your plants before winter. Installing plants earlier in the growing season will strengthen the plants and prevent them from drying out in winter. 

Pests: Hibiscus are not especially prone to pests, but you may encounter them occasionally. A few common insect pests are aphids, mealybugs, caterpillars, and Japanese beetles. Only use insecticides as a last resort, when you know what type of pest you're dealing with. Follow directions on the label.

Japanese beetles have become a widespread problem in parts of the country. One method of dealing with this pest is handpicking the beetles off the plant. Then put them in a bucket of soapy water. Early morning is ideal for removing the beetles, as they are sluggish. You can also use a targeted insecticide if handpicking is not working.  

Prevention is critical for pest control, and the best way to prevent pests is to give your hibiscus proper care. 

 How to Fertilize Hibiscus 

 

Hibiscus requires ample nutrients to thrive. Site selection is essential, as your soil is vital in retaining nutrients. Still, additional nutrients from fertilizing will benefit the plants. A slow-release fertilizer is good, as nutrients are released over months to feed your plants. You only need to apply slow-release fertilizer once a year, typically in spring. Fertilizers that are not slow-release should be used every couple of months during the growing season. A basic, well-balanced fertilizer, such as 10-10-10, is sufficient. 

How and When to Prune Hibiscus 

 

Pruning changes the size or shape of the plant. Before you prune, always have a goal shape and size for your plant. Late winter into early spring is usually the best time to prune hibiscus. Pruning in late winter allows you to assess the plant’s health and remove dead or damaged branches. You should cut Hardy Hibiscus (Hibiscus moscheutos) within a few inches of the ground in early spring.  

You can prune plants during the summer if they're becoming overgrown. Still, early season pruning is more effective for controlling the size of your plant. Pruning a little each year will help you avoid having to cut back the plant severely.  

How to Care for Hibiscus in Pots 

Hibiscus are excellent container plants that can be grown in various outdoor spaces. Caring for hibiscus in pots is different than in the ground. There are some things to consider when growing hibiscus in pots. 

Choosing a pot: The size of your container will depend on the plant size. You can purchase hibiscus of various sizes from your local garden center. The container should generally be 1-2 inches wider than the root ball. 

Soil: Hibiscus requires a high-quality potting mix for growing in containers. Potting mix will typically contain ingredients like peat moss and perlite, which will allow for proper drainage and nutrient uptake. Using soil from your garden isn't ideal because it compacts in the container, making it difficult for water to drain.

Water: Hibiscus will require frequent watering in pots, as they need consistent moisture to thrive. To check the soil moisture levels, simply put your finger a couple of inches into the soil to determine moisture. Water when the soil feels dry.

Fertilizing: Container-grown hibiscus will require fertilizer more often, as potting mix contains limited nutrients. You can fertilize your plants every 2-3 weeks at half the recommended rate to give them the proper nutrient levels. 

Repotting: After a few years, you may need to repot your hibiscus.

Here are two ways to know if your plant needs repotting:

  • Remove the plant and check for circling roots. Circling roots will indicate the plant needs more room.
  • If your plant is starting to look less vigorous and has anemic-looking leaves. 

How to Grow Tropical Hibiscus Indoors 

  

If your climate experiences cold winters, consider bringing your tropical hibiscus inside for the winter. You can also grow Hibiscus indoors year-round, but they do grow best when brought outside during the warmer months. Hibiscus are excellent plants for indoor space. They keep away the winter blues and can make any indoor space feel tropical and spa-like.

  1. Place your hibiscus indoors when you experience temperatures below 50°F at night. For most cold-zone gardeners, this begins mid-September to November, depending on where you live.
  2. Before you bring them inside, you should acclimate the plants to indoor conditions. To acclimate means gradually exposing them to lower light levels, as they will experience indoors. You can do this over 2-3 weeks by moving your plants into more shade every few days. This process makes a move inside less stressful for the plant. Late summer is a good time to inspect your plants for pests before moving them inside. 
  3. Once inside, place your plants near a south or west-facing window, exposing them to increased light. Proper lighting makes it easier for the plant to retain its leaves and bloom during winter. Grow lights are an excellent source of supplemental light if you don’t have access to bright windows.  
  4. As the winter progresses, routinely inspect your plants for pests. Rubbing alcohol is good for pest removal. 
  5. When indoors, hibiscus requires less water compared to summer. You should let the soil dry somewhat between waterings. Be sure to let the water drain out of the container.
  6. Fertilizing is unnecessary in winter, as the plant uses less energy to grow. If you’re growing plants inside year-round, fertilize them once a month at half the recommended rate during spring and summer.  
  7. Prune your hibiscus in late winter to promote growth as the plant is moved outside in summer. Trimming leggy growth back to the rest of the plant will encourage a bushier plant. 
  8. In late spring, you can begin acclimating your plants to outdoor conditions over a 2–3-week period. 

Common Hibiscus Problems

Hibiscus is generally low maintenance, but you may encounter problems from time to time. Yellow leaves are often a sign of abrupt changes in light or moisture. When you move plants inside or outside, these changes often result in yellowing leaves. These symptoms can also be a need for fertilizer or repotting.  

Bud drop is sometimes a problem in extreme heat or cold, as the optimal temperature for hibiscus is 65-85°F. 

Routinely inspect your plants for pest problems. Any issues you discover can be treated using insecticidal soap or rubbing alcohol.   

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2022-07-18 21:49:00