Perennial Hibiscus Plant Care

Perennial hibiscus are hardy plants seen from South Africa to the United States. Yes, even in Africa, you find this flower growing.

While the hardy hibiscus is a heat-loving show stopper in the garden, there is more to this plant than the eye sees.

So, today, we will help you care for the perennial hibiscus to ensure those large bell-shaped flowers bloom.

Hibiscus care card

About Perennial Hibiscus

hibiscus olant

Before we care for the species Hibiscus moscheutos, let us enjoy a history lesson first about this plant. Aah, a history lesson. Yes, and it is an interesting one. The plants are considered ancestors of the native tropical hibiscus growing in Hawaii, Madagascar, Fiji, and Mauritius.

It is an exotic plant that can be traced back to China or India. Yet, in the species, you find some hardier cousins that we will look at today, the Hibiscus moscheutos or the hardy perennial hibiscus.

It is also known as rose mallow, or the swamp rose mallow. You find these plants growing in North America. The good news is that they are easier to care for when you grow them in the garden than tropical hibiscus.

The fascinating thing is that one perennial hibiscus can bloom dozens of flower buds that develop to ten inches long. The flowers last about two days, and when it dies, it forms another bud. Hence, you get long successions of the blooms.

Furthermore, it grows shrub-like, blooming from mid-summer to fall. Some hardy hibiscus plants have rounded, deep green leaves with serrated edges. Others have maple-type leaves that are deeply cut, while other plants have burgundy foliage.

The perennial hibiscus can grow up to six feet tall with multiple upright stems each spring. While not an evergreen, they die back to the ground in winter.

Hardy Hibiscus Plants Care

Perennial Hibiscus Plant Care

It helps to know the USDA garden zones in your region to grow hibiscus plants. The rose mallow does well in zones five to nine, but your tropical hibiscus flowers flourish more in warmer temperatures.

Soil to Grow Perennial Hibiscus Plants

Choosing the correct soil depends on where you live, which helps you find a suitable spot. The hardy perennial hibiscus does not like transplanting and does best in rich, well-draining soil. The best time to plant hardy hibiscus is in spring or fall.

The species prefers an acidic environment, growing in pH levels of 5.5 to 7.5. If you feel the soil pH is low, add peat moss to the potting soil or the bed before you plant it.

Some growing tips for outdoor plants are to provide your hibiscus enough room between other plants to prevent overcrowding. Most importantly, they do not enjoy wet soils, leading to root rot.

Sunlight Needs for Rose Mallow

hibiscus plant in full sun

Whether growing hibiscus indoors or outdoors, choose a spot with full sun; when growing hibiscus in partial shade, the stems become tall and flop over.

If treated as indoor plants, they may be unable to produce those huge blooms than the ones grown outdoors.

Your plants need at least six hours of full sun daily with afternoon shade. If you find your Rose of Sharon sprawls due to the lack of light.

You can use a grow-thru or peony ring for support to keep them growing upright.

Watering Scarlet Rose Mallow

watering hibiscus plant

Hardy hibiscuses have a history relating to tropical climates. Hence, they do love water. You may find you need to water more in the growing season. You can provide your swamp mallow with mulch as an outdoor plant to retain moisture in the warm months in full sun.

The important thing is to keep your hardy plant hydrated by checking the soil daily. While the flowers do not last long, more flowers are sprouting. When winter arrives, keep the soil moist but not soggy to protect it from frost.

Temperature & Humidity

The hardy hibiscus foliage remains green year-round if you live in warm climates. Yet, the flowers will take a break, but the leaves are vibrant, taking their place.

Cold hardy Hibiscus moscheutos is a stunning perennial that boasts dinner-plate-sized blooms in shades of red, pink, and white. Thrives in zones 4-9.

You can then cut them to six inches above the ground to boost new growth when it becomes warmer. When you prune in early summer, it also promotes growth for the stems later.

Fertilizing of Perennial Hibiscus

plant fertilizer

Compared to other perennials, the hardy hibiscus loves feeds. So, feel free to give your swamp mallow a rich flower fertilizer in phosphorus or potassium. Yet, fertilize hibiscus during early summer when the blooms bud.

During winter, your perennial hibiscus plants do not need feed. The reason is that it can burn the roots as the plant is dormant.

Propagating Your Hardy Hibiscus Plant

Compared to other perennials, the hardy hibiscus loves feeds. So, give your swamp mallow a rich flower fertilizer in phosphorus or potassium. Yet, fertilize hibiscus during early summer when the blooms bud. During winter, your perennial hibiscus plants do not need feeding. The reason is that too much fertilizer can burn the roots as the plant is dormant.

Pruning Hibiscus Plants

Pruning hibiscus is an integral part of maintaining the health and appearance. The best time to prune hibiscus is in the late winter or early spring, just before new growth begins. This is typically around March or April, depending on your climate.

You can also do light pruning throughout the growing season to remove dead or damaged branches. You’ll need a pair of sharp, clean pruning shears or loppers. Start by inspecting the hibiscus for any dead or diseased branches.

Steps for Pruning:

  • Start by inspecting the hibiscus for any dead or diseased branches. These should be removed first. Cut them back to where they connect with a healthy branch or the main stem.

  • If your hibiscus has become leggy or too tall, you can reduce some of the older branches to encourage new growth. Make your cuts just above a node where a leaf or bud grows. This will promote branching.

  • Hibiscus can be shaped to your desired form. Trim the outer branches if you want a more compact, bushy look. If you want a taller look, you can let it grow, but keep it in check.

  • Deadhead your hibiscus by removing spent flowers. This keeps the perennial looking tidy and encourages new flower production in the garden.

  • Don’t over-prune your hibiscus. It’s better to prune lightly and gradually rather than cutting it back severely, as this can cause stress to the plant.

After pruning, give your hibiscus a balanced fertilizer and water it well to help with recovery and new growth.

Propagating Your Hardy Hibiscus Plants

Perennial hibiscus plants can propagate from seed or stem cuttings, and we will discuss both methods here for you.

Seed Propagation

With this method, you can propagate hardy hibiscus flowers. We recommend sanding the seeds to help bring moisture into them if you get some seeds. You can do this using fine-grain sandpaper.

Next, soak the seed in water overnight and place the seed in the soil. With the tip of a toothpick, you can make a hole.

Then sprinkle some soil over the seed in the hole. Water, once planted, should take two weeks for your new plants to appear.

Stem Cutting

With cuttings, you can ensure your summer garden is complete with tropical and hardy hibiscus.

  1. Start by taking cutting from softwood or new growth. Softwood is mainly found in spring and early summer.

  2. You can take six inches of cutting and remove the bottom leaves. It helps to cut below the leaf node.

  3. Next, dip that cut end into some rooting hormone and place it in well-drained soil using a mix of potting soil and perlite.

  4. Another great thing is to place a clear plastic bag over the container to keep the moisture.

  5. Keep the soil damp but not wet until it roots. It should take about eight weeks.

Perennial Hibiscus Varieties

You can find hibiscus in different varieties and the largest flower in some. So, group some of these favorites to create a splash of color in the garden.

Lady Baltimore Hibiscus

Lady Baltimore Hibiscus

The plant has a light pink flower with a dark-eyed center and makes a statement no matter where you grow it. You can plant the hardy hibiscus plant in late spring to summer. It dies back in winter and tolerates most soils. The plant flourishes in full sun, and the pink flowers look adorable.

Lord Baltimore

lord baltimore hibiscus

The dinner plate hibiscus has red flowers you find in early spring and continues into early fall. The hibiscus has larger flowers than most other perennials in a garden. It grows upright with a spreading habit of growing well in moist soils. The red flowers stand out in the landscape under full sun.

Lufkin White

Lufkin White

In spring and summer, this hardy hibiscus shows pure white flowers with a burgundy eye. It continues to bloom into fall and is a hardy perennial with upright to spreading habit. So add it to your garden for a display of white flowers.

Perennial Hibiscus Pests

While growing hibiscus is a relatively easy and hardy plant, pests can bother it. The first insect to trouble your hibiscus is a Japanese beetle that feeds primarily on dinner-plate-sized flowers.

You can handpick them to place in a soapy water container, or you can spray organic insecticide. Other insects are aphids, whiteflies, and sawfly larvae.

The latter is a tiny caterpillar living on the underside of leaves. You can use horticultural oil like neem oil to remove them. Other concerns are leaf spots and the best to provide your plants with enough air circulation.

Frequently Asked Questions

While both types of hibiscus have similar-shaped flowers, Hardy Hibiscus blooms are typically larger and come in a wider range of colors, including white, pink, and deep red.

Hardy Hibiscus usually blooms from mid to late summer, and their flowers can last several weeks. The timing can vary depending on the specific variety and local climate.

You can grow Hardy Hibiscus in large containers, which may require more frequent watering. Choose a sizable container and use a well-draining potting mix.

In regions with cold winters, it’s a good idea to mulch around the base of the perennial hibiscus in late fall to insulate the roots. Some gardeners also cut back the stems in late winter or early spring.

Yes, you can propagate Hardy Hibiscus through division or from seeds. The division is typically done in early spring, and seeds can be collected from the spent flower heads.

These plants are not usually preferred by deer, making them a good choice for gardens where deer are a concern.

Popular varieties include ‘Lord Baltimore’ with deep red flowers, Luna series with various colors, and ‘Kopper King’ known for its copper-colored foliage.

Whether you want to buy, sell or simply reach out to other plant enthusiasts, Plantly is the right place to be!

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