Hibiscus How To Guides | By Plant Experts (2024)

Hibiscus Care, Problems, & Solutions

Caring for Hibiscus is about making sure the plants are thriving. Our plant care articles provide the necessary details to give you the greatest chance of success. Afterall, there is nothing worse than investing in the plants, putting the effort into planting them, and then having them fail. Therefore, follow our advice for Hibiscus care and give yourself the best chance of success.

Green Bugs On Hibiscus Flower Buds

The green bugs you see on your hibiscus flower buds are likely aphids. Aphids are tiny, sap-sucking insects that are common pests on many plants, including hibiscus. Look for small, soft-bodied green insects clustered around the flower buds, stems, and undersides of leaves. Often, they will excrete a sticky substance called honeydew, which can coat the leaves and attract ants. Large infestations of aphids can cause the flower buds to become stunted or deformed and leaves may start to yellow.

The most effective way of getting rid of aphids is with an insecticide that states it controls this pest. You can attempt to wash them off but this can deliver a low success rate and requires repeat activity.

How to Care for Hibiscus Plants

Here's a guide on caring for your hibiscus plants to keep them thriving and flowering prolifically:

Light:

Hibiscus are sun-loving plants and need at least 6-8 hours of direct sun per day for optimal growth and flowering.
If growing indoors, place your hibiscus near a north-facing window for maximum sunlight.

Watering:

Water your hibiscus regularly, especially during hot weather. The soil should be moist but not sodden. Allow the top 25 mm of soil to dry slightly before watering again.
Ensure your pot or planting area has good drainage to prevent root rot.
- Wilting leaves and dropping flower buds are signs your hibiscus needs water.
- Yellowing leaves and mushy stems can indicate overwatering.

Fertilizer:

During the growing season (spring and summer), fertilize your hibiscus with shrub fertiliser.
- NB: Too much fertilizer can hinder flower production and damage the plant.
- Reduce or stop fertilizing during the winter months when the plant is dormant.

Pruning:

Regular light pruning throughout the growing season can promote bushier growth and more flowering.
Removing spent flowers (deadheading) encourages the plant to produce new blooms instead of focusing on seed production.
You can prune for shape after flowering.

Potted Hibiscus:

Choose a pot with drainage holes that's slightly larger than the root ball. Repot when the plant outgrows its current container.
If you live in an area with freezing temperatures, bring your potted hibiscus indoors or provide them with adequate protection (mulch around the base, cover with frost cloth).

Pests and diseases:

Keep an eye out for common pests like aphids and scale and treat them promptly.

By following these tips and providing the right environment, you can enjoy a healthy [hibiscus plant].

Why Are The Leaves On My Hibiscus Going Yellow?

Yellow leaves on a [Hibiscus plant] can be due to a few things:

Overwatering: Hibiscus love water, but they don't like to be constantly wet. Excess water can suffocate the roots and prevent them from taking up nutrients, leading to yellowing leaves.
Underwatering: Underwatering can also cause yellowing leaves. They need consistent moisture, especially during hot weather.
Insufficient Light: Hibiscus are sun-loving plants and require at least six hours of direct sunlight daily. If your hibiscus isn't getting enough light, its leaves may start to yellow.
Sudden Light Changes: If your hibiscus has recently been moved from a shady location to a brightly lit spot, it might experience some stress and yellowing leaves as it adjusts. Introduce it to increased sunlight gradually.
Lack of nutrients: Over time, the soil can become depleted of nutrients needed for healthy growth. If your hibiscus isn't getting the nutrients it needs, it might show signs like yellowing leaves. Leaves turning yellow from the bottom up often indicate a nutrient deficiency and you should consider using shrub fertiliser to correct the issue.
Temperature Stress: Extreme temperatures, both hot and cold, can stress your hibiscus and cause yellowing leaves. Ideally, they prefer warm temperatures between 65-85 degrees Fahrenheit (18-29 degrees Celsius).
Pests or Diseases: Pest infestations or diseases can also damage leaves and cause them to turn yellow. Regularly inspect your hibiscus for signs of pests or diseases and address them accordingly.

Finally, some varieties are deciduous, so leaf yellowing in autumn can be perfectly normal.

Hibiscus Fertiliser

Providing the best fertiliser for Hibiscus plants is important to ensure they thrive. The correct fertiliser depends on whether the plant is grown in a pot or in soil, and getting this wrong can be disastrous for your plants. Our articles provide the best advice about fertilising Hibiscus plants so you can achieve the amazing results you are after.

What Is The Best Fertiliser For Hibiscus Grown In A Pot?

Hibiscus grown in containers require different fertiliser to those grown outdoors in soil. In this instance the correct fertilisers to use are either the container plant fertiliser or fertiliser tablets. Each of these will provide safe, sustained, and complete nutrition to the plant for the next 12-months. Using other types of fertiliser can be detrimental to the plant and may result in plant injury or death.

Foliar feeding using a liquid fertiliser can be undertaken if you have time but this is not essential if container plant fertiliser or fertiliser tablets have been used. If you think the plant needs an extra boost or has some yellowing, however, a liquid fertiliser application won’t hurt. A great benefit of foliar feeding is that it helps keep the leaves strong and lush as the nutrition is right where the plant needs it.

What Is The Best Fertiliser For Hibiscus?

Hibiscus are vigorous plants that require feeding to keep them growing optimally. The Plant Company’s shrub fertiliser has been blended to give plants an initial boost and then sustained nutrition for 12-months. We recommend the fertiliser is applied to the soil surface in spring just as the plants start to grow actively. More importantly, we advise that no fertiliser is placed in the hole at planting, but rather spread around the soil surface so it can wash through the roots as it releases. This fertiliser ensures that nutrients remain in the soil around the plant rather than being lost through the soil profile to where the plant cannot reach it. This also applies to plants grown on sandy soils. This shrub fertiliser is therefore very environmentally friendly and longer lasting than most other products in the market.

Foliar feeding using a liquid fertiliser can be undertaken if you have time but this is not essential if shrub fertiliser has been applied. If you think the plants need an extra boost or have some yellowing, however, a liquid fertiliser application won’t hurt. A great benefit of foliar feeding is that it helps keep the leaves strong and lush.

What Is The Best Organic Fertiliser For Hibiscus?

Hibiscus are showy plants that require feeding to keep them looking amazing. A lot of articles have all sorts of advice on this subject which often requires multiple applications, so you use more of their fertiliser. The Plant Company prefers to take a simpler and more environmentally responsible approach. We believe the best organic option is The Plant Company's organic fertiliser which is applied in spring and again in autumn and will keep them well fed. You can safely apply generous amounts of this fertiliser without risk of injuring the plants. More details about this fertiliser are provided with the product.

What Is The Optimum Soil pH For Hibiscus?

The soil pH refers to how acid of alkaline the soil is. Hibiscus prefer a soil pH within the range of 6.2 to 6.5 which means they prefer a slightly acidic soil. As the pH of the soil moves away from this optimum range, the nutrients the plant is taking up (or not taking up) through the roots changes. If the shift in pH is too far, this can result in deficiencies of some nutrients and toxic levels of others. In either case this can cause the plant to become sick or even die a slow death.

The best way to know whether the pH is correct for your plant is to do a test. The Plant Company has pH test kits available that are easy to use and only take a few minutes to get a result. Preferably this test should be completed before planting so any pH issues can be corrected without risking the plant. A pH less 6.2 should have sparing amounts of dolomite lime applied along with shrub fertiliser. A pH above 7 should have small amounts of soil acidifying fertiliser applied. In both instances the fertiliser should be thoroughly mixed into the soil before planting. A retest of the soil pH should be undertaken after four weeks, and small adjustments made again. If the pH is in the optimum range, just use shrub fertiliser thereafter.

Hibiscus Flower Information

This series of articles focuses on common questions about Hibiscus flowers. Varietal information is covered in a later section.

Are Hibiscus Flowers Edible?

Hibiscus flowers are edible. The fleshy part of the flower, particularly the calyces (sepals that enclose the flower bud) have a tart, cranberry-like flavour.

Can You Cut Hibiscus Flowers For A Vase?

Hibiscus flowers aren't the best choice as a cut flower in a vase because they have a short vase life. They typically only last for a day or maybe two at best. The short vase life is due to the stems not readily absorbing moisture coupled with a large flower that requires constant moisture to stay turgid.

Do Bees Like Hibiscus Flowers?

Bees love hibiscus flowers as the flowers have many attractive properties:

Hibiscus flowers produce a plentiful amount of nectar, a sweet, sugary liquid which is a food source for bees.
The flowers also offer a good source of pollen, which bees collect to feed their young and nourish the hive.
The vibrant colors of hibiscus flowers are highly attractive to bees. These colors act as visual signals, guiding bees to the nectar and pollen rewards within.
The large flowers make it easy for bees of various sizes to land on them and access the nectar and pollen.

Hibiscus Flower Parts And Their Functions

Hibiscus flowers play an important function in the plant's reproduction. Some of the key flower parts and their functions are as follows:

Sepals (collectively called the calyx):
- These are the outermost layer of the flower bud, typically green and leaf-like. Their main function is to protect the developing flower bud before it opens.
Petals (collectively called the corolla):
- These are the large, showy flower parts that come in vibrant colors like red, yellow, orange, pink, white, and purple. They attract pollinators, such as butterflies and bees, to the flower.
Stamens:
- These are the male reproductive organs of the flower. Each stamen consists of two main parts:
  - Filament: A thin, stalk-like structure that holds up the anther.
  - Anther: A sac-like structure that produces pollen grains, which contain the male sex cells of the plant.
Pistil:
- This is the female reproductive organ of the flower, located in the centre. It typically consists of three parts:
  - Stigma: The sticky, upper part of the pistil that receives pollen grains.
  - Style: A slender tube that connects the stigma to the ovary.
  - Ovary: The base of the pistil that contains ovules (potential seeds). If pollen grains successfully land on the stigma and germinate, a tube grows down the style, fertilizing the ovules in the ovary. The ovary will then develop into the fruit of the plant.

The different flower parts work together to ensure successful reproduction. The sepals protect the bud, the petals attract pollinators, the stamens produce pollen, and the pistil receives pollen and houses the developing seeds.

How Many Pistils Does A Hibiscus Flower Have?

A hibiscus flower typically has only one pistil in the centre of the flower. This pistil is made up of three parts:

Stigma: The sticky upper portion that receives pollen grains.
Style: A slender tube that connects the stigma to the ovary below.
Ovary: The base of the pistil that contains ovules (potential seeds).

How to Get Hibiscus to Flower

Getting your [Hibiscus plant] to flower is all about providing the right conditions for healthy growth. Some key factors to consider include:

Hibiscus are sun-loving plants and need at least six hours of direct sun per day to thrive and flower.
Water your hibiscus regularly, especially during hot weather. The soil should be moist but not sodden.
Ensure your pot or planting area has good drainage to prevent root rot.
During the growing season (spring and summer), fertilize your hibiscus with shrub fertiliser. But avoid overdoing it as to much fertiliser can injure the plant.
Regular light pruning can promote bushier growth and more buds that will flower.
Deadheading, or removing spent flowers, encourages the plant to produce new flowers instead of focusing on seed production.
Hibiscus prefer warm temperatures, ideally between 65-85 degrees Fahrenheit (18-29 degrees Celsius). Cold temperatures will certainly discourage flowering.
If your hibiscus is rootbound or in a pot that is too small, it will struggle to flower. Consider repotting it into a larger container with fresh potting mix.
Younger hibiscus plants (less than 2 years old) may not flower readily.
Some hibiscus varieties naturally flower more abundantly than others. Research your specific type to understand its typical blooming habits.

By following these tips and addressing any potential issues, you can create a flourishing environment that will encourage your hibiscus to reward you with beautiful flowers.

How To Infuse Hibiscus Flowers In Oil

Infusing hibiscus flowers in oil create a beautiful and potentially beneficial oil. There are a few steps depending on what you are wanting to achieve. The first is to choose the carrier oil:

For hair care: Coconut oil, almond oil, avocado oil, grapeseed oil
For skin care: Jojoba oil, sweet almond oil (be sure it's labelled for skin)

1. If using fresh flowers, wash them gently and pat them dry. Ideally, let them air dry completely for a day or two to remove excess moisture. While not essential, crushing the flowers can help release their beneficial properties more readily into the oil. You can use a mortar and pestle or simply break them up with your fingers.

2. In a sterilized jar, add the desired amount of carrier oil, then add the hibiscus flowers. A good rule of thumb is to use a 1:1 ratio of flowers to oil by volume. However, you can adjust this depending on the desired potency of the infused oil.

3. Fill the bottom pan of your double boiler with water and bring it to a simmer. Place your jar containing the oil and flowers in the top pan, ensuring it doesn't touch the simmering water. Heat for 2-4 hours, stirring occasionally. Alternatively, you can do a slower infusion using the sun. In this instance, place the jar with oil and flowers in a sunny location for several weeks (4-6 weeks or longer).

4. Once the infusion period is complete, allow the oil to cool completely. Then, strain the oil through a fine-mesh strainer or cheesecloth to remove the flower particles. You can use a coffee filter for even finer filtering, if desired.

5. Pour the strained oil into a clean, dark glass jar with a lid. Store it in a cool, dark place for up to 6 months.

Please note that if you are using the oil for skin care, always perform a patch test on a small area of your inner arm first to check for any allergic reactions.

Hibiscus General Information

These stunning flowering plants bring a touch of the tropics wherever they grow. With blooms in vibrant reds, yellows, oranges, and more, they're a favourite for gardens and landscapes. But hibiscus are more than just pretty flowers as their large and showy blooms can be used for tea, and some have medicinal properties. This series of articles sheds some light on these important subjects.

About Hibiscus

Hibiscus is a genus of flowering plants in the mallow family, Malvaceae. The genus is quite large, comprising several hundred species that are native to warm temperate, subtropical, and tropical regions throughout the world. The species are renowned for their large and showy flowers and those species are commonly known simply as "hibiscus", or less widely known as rose mallow. Other names include hardy hibiscus, rose of sharon, and tropical hibiscus.

Hibiscus plants can be shrubs, trees, or even perennial herbs. They typically have large, showy flowers that come in a wide variety of colors, including red, yellow, orange, pink, white, and purple. The flowers can be single or double, and they often have five petals. The leaves of hibiscus plants are usually lobed and may be smooth or hairy.

They are popular ornamental plants and are grown for their beautiful flowers. They are also used in hedges and screens. Some species of hibiscus are used to make tea, and some have medicinal properties. The hibiscus flower is the national flower of Malaysia.

What Are The Different Types Of Hibiscus?

There are hundreds of Hibiscus species, but there are three main categories commonly grown in gardens:

Tropical Hibiscus (Hibiscus rosa-sinensis)
- This is the most popular type of hibiscus, known for its large, showy flowers in vibrant colors. It's not winter-hardy and thrives in warm climates or as a container plant brought indoors during cold weather.
Hardy Hibiscus (Hibiscus syriacus)
- Also known as Rose of Sharon, this type is known for its woody stems and large, trumpet-shaped flowers. It's winter-hardy and can tolerate colder climates.
Swamp Hibiscus (Hibiscus moscheutos)
- This herbaceous perennial is native to North America and known for its giant, dinner-plate-sized flowers. It prefers moist soil and tolerates colder climates.

What Is Rose of Sharon?

Rose Of Sharon is the common Name for Hibiscus syriacus. This is a flowering shrub native to eastern Asia and is widely grown around the world. It's known for its:

Large and showy flowers: They come in various colors like white, pink, purple, lavender, and red. The flower shape is typically single or double, with a trumpet-like appearance.
Deciduous nature: Unlike some tropical hibiscus varieties, Hibiscus syriacus loses its leaves in autumn and goes dormant during winter.
Hardiness: This species is more winter-hardy and can tolerate colder climates.

What Is So Special About The Rose Of Sharon?

The Rose of Sharon (Hibiscus syriacus) holds a special place in many areas, offering a combination of beauty, resilience, and cultural significance. Here's a breakdown of what makes it special:

Aesthetics:

Rose of Sharon produces large, trumpet-shaped flowers in vibrant colors like white, pink, purple, lavender, and red. They flower throughout summer and into autumn.
It offers a continuous display of beautiful flowers for several weeks.

Resilience:

This shrub thrives in a variety of climates, tolerating moderate warm and cold climates.
Rose of Sharon requires minimal care. Once established, it's relatively drought-tolerant and only needs occasional trimming.

Cultural Significance:

Biblical Reference: While the exact plant in the Song of Solomon is debated, "Rose of Sharon" has become a symbolic name associated with beauty and flourishing.
Symbol of Longevity: In some cultures, the Rose of Sharon symbolizes longevity and enduring beauty due to its hardiness and long lifespan.

The Rose of Sharon is widely used in landscaping, bringing vibrancy to gardens, parks, and public spaces. It can be grown as a single specimen, incorporated into hedges, or maintained as a small tree.

What Is The Hibiscus Tree?

The term "hibiscus tree" can be a little misleading as most are shrubs and some can grow into small trees. Many hibiscus reach heights of 2.5 to 5 metres with a woody trunk and branches. These are often referred to as "hibiscus trees" but technically aren't true trees since they typically have multiple stems emerging from the base.

A few hibiscus species can grow into true trees with a single trunk reaching 6-10 metres tall. These are less common, but some examples include Hibiscus elatus (the Cottonwood Hibiscus) and Hibiscus tiliaceus (the Beach Hibiscus).

What Is The Lifespan Of A Hibiscus Plant?

The lifespan of a [hibiscus plant] varies depending on the type of hibiscus and the growing conditions. Hardy hibiscus plants can live for 20-50 years, while tropical hibiscus plants typically live for 5-10 years.

To prolong the lifespan of your hibiscus plant, be sure to plant it in a location where it will receive full sun or partial shade and has a well-drained soil. Water your hibiscus plant regularly, especially during the first growing season and fertilise it every year with shrub fertiliser. Deadhead spent flowers to encourage new growth. Mulch around your hibiscus plant to help retain moisture and suppress weeds.

Where Are Hibiscus Native To?

While hibiscus is a truly diverse genus with over 200 species, their origins are not singular. The answer depends on the specific type of hibiscus:

Tropical Hibiscus: This group, known for their large, brightly coloured flowers, originates in warm regions around the equator. They're native to areas like Mauritius, Madagascar, Fiji, Hawaii, and potentially China or India. This explains their preference for warm temperatures and humid environments.
Hardy Hibiscus: These sturdier hibiscus varieties, like the Rose of Sharon, boast smaller blooms and tolerate cooler climates. Their origins are primarily in temperate Asia, specifically areas like China and Korea.
Other Species: Within the vast hibiscus genus, you'll find species with more specific native ranges. For example, Hibiscus coccineus originates from the southeastern United States, while Hibiscus diversifolius can be found in both New Zealand and various tropical regions.

Hibiscus Propagation

Hibiscus propagation is a relatively straightforward process when you have the right advice. They are easily rooted, and our articles give you the best chance of doing this successfully and efficiently.

How to Grow Hibiscus From Seed

Hibiscus can be grown from seed with a little patience. The most critical element is to start with fresh seed. The Plant Company recommends that the seeds are soaked overnight in water to soften the seed coat. Simply place the seed onto well-draining potting mix, cover with a fine layer of vermiculite or sifted potting mix, and place in a warm spot. Ensure the tray does not dry out but also make sure the soil is not sodden. The seedlings should emerge in 2-3 weeks and be ready for transplanting at week 8.

How To Propagate Hibiscus by Cuttings

Hibiscus are easily propagated from stem cuttings. Semi-hardwood cuttings cuttings are usually any time between autumn and mid-spring. A stem about 12 cm long is trimmed into a cutting using secateurs with 2-3 leaves at the top and just below a node. Any flower buds are removed and a nick is taken from the base of the cutting to expose more tissue. The cutting is dipped in rooting hormone for 5-10 seconds and then inserted into propagation growing media. The tray of cuttings is placed under mist with bottom heat also applied. The cuttings will have taken root inside of four weeks as a general rule. That said, woodier cuttings can take a little longer.

Hibiscus Varieties & Recommendations

Choosing a Hibiscus that works for you can be challenging given the sheer number that are available. Working through the different varieties, how big the flowers are, and so on, can take considerable time. The Plant Company’s series of short articles aims to offer concise and easy to follow advice and recommendations so you can determine the variety for your needs.

Hawaiian Punch Hibiscus

The Hawaiian Punch Hibiscus is not a specific variety within the hibiscus genus but rather a trade name used by some nurseries and plant retailers specifically for Hibiscus rosa-sinensis cultivars. These are typically greenhouse-grown hibiscus plants that are prized for their large and bold flowers. Be aware that they been raised in a greenhouse so have not been hardened off to cooler temperatures. If they are planted into a garden then frosted, they are unlikely to survive.

Hibiscus Flower Varieties In NZ

The list of Hibiscus varieties that The Plant Company has worked on, propagated, and marketed is extensive. Our database of Hibiscus varieties is listed below:

Hibiscus 'Agnes Gault'
Hibiscus 'Apricot Chiffon'
Hibiscus 'Apricot Single'
Hibiscus 'Blue Thunder'
Hibiscus 'Blueberry Hill'
Hibiscus 'Blushing Bride'
Hibiscus 'Bright Lights'
Hibiscus 'Brother Anthony'
Hibiscus 'Cairo Red'
Hibiscus 'Cherry Cheesecake'
Hibiscus 'Collie Mullens'
Hibiscus 'Cream Bun'
Hibiscus 'Crown of Bohemia'
Hibiscus 'Crown of Warringah'
Hibiscus 'Dainty Pink'
Hibiscus 'Diana'
Hibiscus diversifolius
Hibiscus 'DJ O'Brien'
Hibiscus 'Dr Katzuki'
Hibiscus 'El Capitoilo'
Hibiscus 'Erin Rachel'
Hibiscus 'Fifth Dimension'
Hibiscus 'Fiji Sunshine'
Hibiscus 'Fijian White'
Hibiscus 'Full Moon'
Hibiscus 'Gem'
Hibiscus 'Golden Queen'
Hibiscus 'Harry Boris'
Hibiscus 'Heidi'
Hibiscus 'Helene'
Hibiscus 'Hiawatha'
Hibiscus 'Isobel Beard'
Hibiscus 'Jeanne d Arc'
Hibiscus 'Jim Berry'
Hibiscus 'Kiwi Glow'
Hibiscus 'Lady Cilento'
Hibiscus 'Lady Ferguson'
Hibiscus 'Lady Stanley'
Hibiscus 'Lemon Chiffon'
Hibiscus 'Leopoldii'
Hibiscus 'Lollipops'
Hibiscus 'Macdelveons Yellow'
Hibiscus 'Madonna'
Hibiscus 'Molly Cummings'
Hibiscus 'Mrs George Davis'
Hibiscus 'Mystic Charm'
Hibiscus 'Nathan Charles'
Hibiscus 'Norman Lee'
Hibiscus 'Old Frankie'
Hibiscus 'Paeonyflorus'
Hibiscus 'Peach Blow'
Hibiscus 'Peach Blush'
Hibiscus 'Pearl Harbour'
Hibiscus 'Pink Chiffon'
Hibiscus 'Pink Double'
Hibiscus 'Popsicle'
Hibiscus 'Prince of Orange'
Hibiscus 'Psyche'
Hibiscus 'Red Heart'
Hibiscus richardsonii
Hibiscus 'Ritzy'
Hibiscus rosa-sinensis
Hibiscus 'Ross-Estey'
Hibiscus 'Royal Highness'
Hibiscus 'Ruby'
Hibiscus 'Ruby Tuesday'
Hibiscus 'Silver Queen'
Hibiscus 'Simmonds Red'
Hibiscus 'Snow White'
Hibiscus 'Snowdrift'
Hibiscus 'Summer Tan'
Hibiscus 'Sun Showers'
Hibiscus 'Suva Queen'
Hibiscus syriacus
[Hibiscus syriacus 'Coelestis']
Hibiscus tiliaceus 'rubra'
Hibiscus trionum
Hibiscus 'Tropical Peach'
Hibiscus 'Tui Song'
Hibiscus 'White Chiffon'

Red Hibiscus Varieties

There are a few popular red flowering Hibiscus varieties available in NZ. The ones considered most popular are provided below:

Hibiscus 'Cairo Red'
Hibiscus 'Hiawatha'
Hibiscus 'Leopoldii'
Hibiscus 'Molly Cummings'
Hibiscus 'Psyche'
Hibiscus rosa-sinensis
Hibiscus 'Royal Highness'
Hibiscus 'Ruby'
Hibiscus 'Silver Queen'
Hibiscus 'Simmonds Red'

Yellow Hibiscus Varieties

There are a few popular yellow flowering Hibiscus varieties available in NZ. The ones considered most popular are provided below:

Hibiscus 'Fiji Sunshine'
Hibiscus 'Full Moon'
Hibiscus 'Kiwi Glow'
Hibiscus 'Lady Ferguson'
Hibiscus 'Lemon Chiffon'
Hibiscus 'Macdelveons Yellow'
Hibiscus tiliaceus 'rubra'

How And When To Prune Hibiscus

Growing Hibiscus or a Hibiscus hedge takes some thought and planning to ensure you get what you are after. Factors such as the hedge spacing, desired height, and variety are all important considerations. The Plant Company have produced this series of articles to provide advice for trimming a Hibiscus hedge and pruning Hibiscus so you can manicure your plants with confidence and success.

How Do You Prune A Hibiscus Bush?

Hibiscus are typically not pruned at all but rather trimmed to contain and shape the plant. Where trimming is required, this is best done after the main flush of flowering. For some varieties this is summer whereas for others it is autumn. In some instances, there is no end to flowering as some varieties which flower sporadically even after the main flush. In such cases it is best to just trim after the main flush in spring. Trimming at these times will result in more and better flowers as the plant has not wasted a lot of effort producing flower buds that would otherwise be cut off with later trimming.

When plants are trimmed using secateurs, any dead or diseased stems should be removed as a priority. Such stems should be cut back flush against the stem they originate from. Branches can now be thinned out in a similar manner to give a more open and visually balanced plant. Normally the plant is trimmed to the desired shape and size first before considering whether it needs to be opened up or not. This choice to “open” up a plant is entirely about the look you are wanting to achieve rather than any necessity.

It is worth understanding that flowers are produced off stems from the previous seasons’ growth. Therefore, if you cut off all the new growth, you will only see flowers produced on the older stems the next season. For this reason, there is always a compromise between trimming and flowering. The Plant Company advises that plants should be trimmed to shape and size as the first priority as they grow quickly and will be flowering fully before you know it.

How Hard Can I Prune A Hibiscus?

Not all Hibiscus will sprout new shoots when cut right back and this can be a hit and miss exercise. In general, the younger the plant, the more likely it will recover from aggressive trimming. However, this relies on the plant having heathy stems at the outset. If the stumps have any dead wood, they may not shoot or may only shoot off one side. Similarly, stumps that still have actively growing foliage may not sprout unless all the foliage connected to that stem is completely removed.

Severe pruning using a pruning saw or chainsaw is best undertaken during summer. Multiple shoots will generally grow from each stump which can be thinned back to one or the number desired. The plant will not produce flowers on the new shoots until the following year. Please note: Hibiscus grown in heavy shade environments may also struggle to re-establish even if they sprout new shoots.

The Plant Company advises that you should always err on the side of caution with aggressive pruning and accept that there is a 50% chance the plant will not recover from aggressive pruning.

How To Make A Topiary Standard Hibiscus

Creating a Hibiscus topiary standard requires both patience and a straight, single-stemmed plant to start off with. The plant is staked to grow with a straight trunk to just past the mid-height of the topiary (i.e., ball). All the side branches are trimmed off to about 10 cm above the mid-point of the topiary. The top of the plant is cut off just above the mid-point of the ball to encourage sprouting just below the cut. As the new stems grow, they are routinely “tipped” (i.e., the top bud is pinched out) to encourage more shoots. All the time, the ball is progressively shaped until the desired size is achieved. This process can take two years (or more) to complete. If all this seems too hard or you don’t have the patience, contact us and we can generally supply your needs.

What Is The Best Hibiscus For A Hedge In NZ?

Only Rose of Sharon (Hibiscus syriacus) should be used as a hedge in NZ as it is both cold-hardy and tolerant of pruning. This species is a deciduous shrub that grows to 2.5-4 m tall and is usually trimmed into a hedge that is 1-2 m tall. It has large, showy flowers in shades of white, pink, purple, and blue during summer. Some popular varieties include Hibiscus 'White Chiffon', Hibiscus 'Red Heart', and Hibiscus 'Blushing Bride'. In warmer regions, Hibiscus rosa-sinensis makes for a beautiful evergreen hedge if you are frost free.

What Is The Best Time To Trim Hibiscus?

After the main flush of flowering is the best time to trim Hibiscus. For some varieties this is summer whereas for others it is autumn. In some instances, there is no end to flowering as some varieties which flower sporadically even after the main flush. For such varieties it is best to just trim after the main flush in spring.

Some reports suggest that winter is the best time to trim Hibiscus but this is simply not accurate. Yes, the plants can be pruned at this time, but The Plant Company do not recommend it as any trimming is better undertaken soon after flowering so the plant is not producing flower buds unnecessarily. Pruning at the correct time will result in more and better flowers on your plants. A good pair of secateurs is all you need to complete this task.

How to Plant and Grow Hibiscus

Planting Hibiscus and getting them to grow well is generally easy when you get a few of the basics right. This involves planting them in the right soil type, choosing the most ideal planting position, selecting the best variety, and ensuring the plants have the essentials to thrive. The Plant Company has the right advice to give you the greatest chance of success when growing a Hibiscus.

Do Hibiscus Grow In New Zealand?

Yes, Hibiscus plants can grow in New Zealand. There are two main types of hibiscus plants: hardy hibiscus and tropical hibiscus. Hardy hibiscus plants are more tolerant of cold weather, while tropical hibiscus plants prefer warmer temperatures.

Some popular varieties of hardy hibiscus that grow well in New Zealand include:

Hibiscus syriacus
Hibiscus moscheutos
Hibiscus coccineus
Hibiscus richardsonii

Some popular varieties of tropical hibiscus that grow well in New Zealand include:

Hibiscus rosa-sinensis
Hibiscus tiliaceus
Hibiscus schizopetalus
Hibiscus hamabo

Do Hibiscus Need Full Sun?

Hibiscus plants need full sun to thrive. They need at least six hours of direct sunlight per day, and with any less they will produce fewer flowers and become “stretched”. However, it is important to protect hibiscus plants from too much direct sunlight in hot climates, as this can scorch their leaves.

How Tall Do Hibiscus Grow?

The height of a [hibiscus plant] depends on the specific species:

Tropical Hibiscus (Hibiscus rosa-sinensis): 1 to 3.5 metres (3 to 12 feet). These are typically large shrubs but can reach small tree size in ideal conditions.
Hardy Hibiscus (Hibiscus syriacus): 1.5 to 3 metres (5 to 10 feet).
Swamp Hibiscus (Hibiscus moscheutos): 1 to 2.5 metres (3 to 8 feet).

How To Grow A Hibiscus Hedge

Hibiscus make beautiful hedges and are sometimes used for this purpose. The first challenge is to choose the right variety as they do differ in how high and quickly, they will grow. Check out our range and the detailed information that accompanies each of our Hibiscus varieties to make sure you get the right one!

Plants are usually spaced 50 cm apart for hedging. They can be planted up to 30 cm apart if a dense hedge is required quickly. They will fill in, even if planted at 75 cm apart, though the density of the foliage at the base of the plants can start to be reduced at the wider spacing. Remember that the number of plants for a hedge 5 m long and spaced 50 cm apart is 11 (not 10) as you need one at both the start and end.

If a narrow and dense hedge is required, the trimming will need to start early. That is, start clipping the sides and top with secateurs well before it reaches the desired height and width. Each time a stem is cut, the buds on the remaining stem will sprout. Each stem will now end up with two or more shoots growing from it. Repeatedly doing this forces the plant to keep branching and therefore makes the plant denser. Once the hedge is getting close to the desired width, the trimming regime can move to an annual basis.

How To Plant Hibiscus

Choose a full sun position with good drainage and moderate shelter for your Hibiscus plant. The hole should be dug to at least 50-75% deeper and wider than the container the plant is currently growing in. A good planting spade makes this job a lot easier. The Plant Company recommends incorporating compost or sheep pellets into the soil to provide additional organic material, but this is not essential. Do not put fertiliser in the bottom of the hole, rather spread that on the soil surface after planting, and preferably do this when the plant is actively growing in spring.

Remove the plant from the container it is growing in by either pulling it free or by cutting the bag. We recommend cutting the bag or container, especially for larger grade plants, to minimise any chance of damaging the roots. If the roots have been growing in a circle or are all bound up, you can tease them apart if you want but this is not essential. Similarly, you don’t need to remove any of the growing media. The Plant Company does not recommend cutting the roots, even if the plant is root-bound as this offers no benefit. This is explained in our article, Managing Rootbound Plants.

Now place the plant in the hole and make sure it is level with the soil surface before filling in around it. If it is sitting above the soil surface, dig more out. If it is below, put in more soil and retest the level. Once the plant is set level with the soil surface, add more soil gradually and firm it around the plant using gentle pressure from your fingers as you go. Scatter shrub fertiliser across the soil surface after planting and the give the plant a good watering. If the plant is taller than 30 cm you might want to consider staking it to give it a bit of extra support and use tree ties for secure and appropriate holding.

How To Repot A Hibiscus Plant

To repot a [hibiscus plant], choose a pot that is no less than twice the size of what it is currently growing in and that has plenty of drainage holes in the bottom. Fill the bottom of the pot to about 1/3 of the way up with potting mix. Do not use soil or compost when growing plants in a container and do not add fertiliser.

Remove the plant from the container it is growing in by either pulling it free or breaking the pot apart. The Plant Company recommends cutting the bag or container, especially for larger plants, to minimise any chance of damaging the roots. If the roots have been growing in a circle or are all bound up you can tease them apart if you want but this is not essential. Similarly, you don’t need to remove any of the growing media. The Plant Company does not recommend cutting the roots, even if the plant is root-bound as this offers no benefit. This is explained in our article, Managing Rootbound Plants. Add more potting mix and firm this around the plant using gentle pressure, then water well. They should be watered once a week during hot weather and fortnightly during cooler periods.

What Is The Best Soil For Hibiscus?

Soils rich in fertility and organic matter that are well-drained will grow amazing Hibiscus plants. The soil should be well prepared with either compost or sheep pellets mixed in at planting or spread on the soil surface after planting. It is important that the soil being planted into won’t restrict root growth and for this reason, clay soils are not well suited to Hibiscus. Clay soils also tend to be very wet which will negatively impact the performance of the plant and can ultimately result in plant death. The Plant Company recommends that poor draining, or clay soils be avoided for Hibiscus.

When Should I Plant Hibiscus?

Hibiscus are best planted any time from mid-autumn until late spring. During this time, they can cope with the stresses associated with planting (root damage mainly) more easily than if they must also cope with heat and moisture stress as well. They can be planted in summer provided they are well-watered, and the roots have plenty of growing media attached when planted. If watering is a challenge, The Plant Company advises planting any time from late-autumn through until early-spring. Make sure you have a good planting spade to make this job a lot easier.

When To Water Hibiscus

Hibiscus are lush plants, and this foliage requires good soil moisture during dry periods to stay fresh and keep growing actively. The Plant Company advises generous watering daily or every second day during summer. If the flowers or young stems start to droop, you need to water immediately as this is a sign of severe moisture stress and is not normal. Plants should be watered thoroughly in the morning or in the evening for water conservation purposes. During cooler times of the year watering will usually only be required during dry periods or for a short period after planting.

Over-watering can be a problem with most plants including Hibiscus. Too much and the plants will develop root rot issues and slowly deteriorate. The first tell-tale sign of over-watering is a yellowing of the leaves. If the plants are on a well-drained site or growing in well-drained growing media this should rarely be an issue. Clay soils tend to be poorly drained and can result in the equivalent of over-watering. For this reason, The Plant Company advise against planting Hibiscus on such soils unless drainage issues are addressed.