How to Propagate Hibiscus

Hibiscus plant information, physiology, and uses

Hibiscus belongs to the genus of flowering plants (Hibiscus) in the mallow family, Malvaceae. They are known for their large flowers of different sizes and colors. There are more than a hundred species found that are used throughout the world as ornamentals, food, and medicine.

The trumpet-shaped flowers of Hibiscus, boasting five or more petals, display a diverse array of colors, ranging from white, pink, and orange to red, yellow, purple, and various multi-hued patterns. Hibiscus blossoms open wide, enticing a variety of pollinators, from bees to hummingbirds.

Carolus Linnaeus named the plant “Hibiscus”. The scientific (Latin) name of the plant is Hibiscus rosa-sinensis, which means “rose of China.” However, Hibiscus is not closely related to true roses. Moreover, Hibiscus is also known as rosemallow and belongs to a genus (Hibiscus) of plants characterized by vibrant-colored flowers. While it primarily thrives in tropical regions, certain species can be found in cooler climates.

Hibiscus rosa-sinensis holds the honor of being Malaysia’s national flower, known as Bunga Raya in Malay. Introduced to the Malay Peninsula in the 12th century, it was designated the national flower in 1958, courtesy of the Ministry of Agriculture.

Diversity of Hibiscus:

There are more than a hundred species of Hibiscus, each with unique characteristics.

Some species are shrubs, while others are trees or even vines.

The flowers can be seen in various colors like red, pink, yellow, orange, and purple.

Methods of Propagation in Hibiscus:

Commonly used types of asexual propagation are:

● Stem cutting

● Grafting

● Air layering

Progapagating Hibiscus with stem cuttings 

Stem Cutting in Hibiscus:

Together with seed propagation, propagation through stem cuttings is the most convenient and popular method of propagating hibiscus plants. 

• A stem cutting is any cutting taken from the main shoot of a plant or any side shoot growing from the same plant or stem. The more experienced the propagator, the easier and more successful the process. 
• However, there are a few general considerations that help in the selection of suitable cutting. The cuttings must be healthy and robust (sufficient reserve food to keep tissues alive until roots and shoots are produced). The shoots with high carbohydrate content usually root better. Ringing or notching stems down to the wood are useful practices to maintain high carbohydrate content in a shoot. As a general rule, cuttings from young plants root better, but if older shoots of the plants are cut back hard, very often, they can be induced to produce suitable shoots for rooting.

Broadly, there are four types of stem cuttings:

1. Hardwood
2. Softwood
3. Semi-hardwood
4. Herbaceous cuttings

1. Hardwood cuttings in Hibiscus:

• Hardwood cuttings are made from the mature and lignified stems of shrubs and trees. It is the simplest method of plant propagation. Such cuttings are easy to secure and easily handled, stored, and transplanted.
• Hardwood cuttings are prepared during the dormant season, usually from one-year-old immature shoots of the previous season’s growth. Only healthy shoots are selected, and the weak, fast-growing shoots with long internodes should be avoided.
• The length of the cuttings varies from 10 to 45 cm in length and 0.5 to 2.5 cm in diameter, depending on the species.
• Usually, 25-30 length cuttings as thick as a pencil are preferred. Each cutting should have at least two buds.
• While preparing the cutting, a straight cut is given at the base of the shoot below the node, while a slanting incision, 1 to 2 cm above the bud, is given at the top of the cutting. This protects the cutting from holding water (r.g. during rainfall), avoiding fungal infections. 
• It is often advantageous to take hardwood cuttings with a heel, with a piece of older wood attached to the base of a cutting. Mallet hardwood cutting should also be preferred.

2. Semi-hardwood cutting in Hibiscus:

• The semi-hardwood cuttings are prepared from partially matured, slightly woody shoots. These are succulent, tender, and usually prepared from wood grown during the current season.
• Usually, those shoots are considered ideal for the preparation of semi-hardwood cuttings. The length of the cuttings varies from 7 to 20 cm.
• The cuttings are prepared by trimming them with a straight cut below a node and removing a few lower leaves. However, retaining two to four leaves on the cuttings is better.
• Treating the cuttings with IBA (5,000 ppm) before planting gives better results. Similarly, one-quarter of their length should be inserted in the soil while planting.
• The best time for taking such cuttings is summer when new shoots have emerged and their wood is partially matured.

3. Softwood cuttings in Hibiscus:

• Softwood cuttings are called cuttings prepared from soft, succulent, and non-lignified shoots, which have not become hard or woody.
• Usually, the cutting size is 5.0 to 7.0 cm, but it varies from species to species.

Methods of Grafting in Hibiscus

This advanced technique allows to combine desired traits from different hibiscus varieties onto a single rootstock.

Some of the most popular types of grafts that can be used on Hibiscus are:

• the cleft graft
• bark graft
• tongue graft 

Cleft grafting in Hibiscus

It is an old grafting method and is particularly suitable in rootstocks with a diameter greater than the scion.

• Rootstock with 5-7 cm or more girth is selected for this purpose.
• The rootstock is cleft grafted after cutting the stock 45 cm above the ground level.
• The beheaded rootstock is split about 5 cm deep through the center of the stem with a sharp knife or a chisel.
• When the knife is removed, a hard wooden wedge is inserted to keep it open for the subsequent insertion of the scion.
• The 15-20 cm scion is taken from a terminal shoot over three months old and then wedged securely (6-7 cm).
• The cleft of the scion is slipped into the split of the rootstock. In thicker stocks, more than one scion can be inserted. The graft should be thoroughly waxed to prevent wilting of the scion.
• The scion starts growing after 2 to 3 months. The right time for cleft grafting is the later part of the dormant season or just before the start of active growth.

Bark grafting in Hibiscus

• It is a simple and rapid method of propagation and gives high success. Moreover, it does not require special instruments either. Some nursery experts prefer it because it can be done without splitting the stub, which prevents the entry of decay organisms.
• Similarly, it can even be done in branches 25 to 30 cm long. It should be done in spring when the rootstock bark slips easily.
• It is important to note that the scion used in bark grafting should be dormant. In actual practice, the stock is first sawed off at a point where the bark is smooth.
• If the stock is thick, many scions can be inserted. The bark is split downward for each scion, about 5 cm from the top end of the stub. Scions of 10-12 cm long, containing 2-3 buds, are collected from dormant wood and are prepared by giving a slanting cut (5 cm) downward along one side of the base.
• On the other side, a small cut is given. The more extended the cut of the scion is placed against the wood.
• The scion is kept firmly by using adhesive tape or string.
• Afterward, all the exposed parts in the grafted area should be covered with melted wax.
• If grafting is successful, the scion will start sprouting after 6-8 weeks.

Tongue grafting in Hibiscus:

Tongue grafting is a popular technique for grafting hibiscus plants. It is a relatively simple and reliable method that can propagate desirable varieties, combine different characteristics onto a single plant, or save a diseased or damaged plant.

Air layering

Air layering is a specialized form of layering that was originally introduced in China and is now widely used for propagating many horticultural plants.

It is popularly known as gootee or marcottage. In all layering forms, rooting is induced by bringing the stem in contact with the soil or other moist medium, but air layering is quite distinct from others.

• In this method of layering, the moist medium is brought to the stem, the latter being left in its original position, i.e……. roots are formed on the stem well above the ground without using soil at all.
• It is a useful method for propagating rare and valuable plants that are difficult or impossible to propagate through cuttings and where ordinary layering methods are not practicable.
• Thus, plants with rigid branches borne high above the ground, which could not be brought down to a low level, are highly suitable for air layering.
• Clean young shoots are best for air layering.
• They are prepared by making an upward cut about 5 cm long at or about the center of the shoot.
• The shoot is then girdled by removing a 2cm wide bark ring.
• The upper part of the wound is applied with IBA paste made in lanolin.
• The wound is covered with moist sphagnum moss in a way that provides complete cover.
• In the past, there had been difficulty in air layering because of drying the moss grass. Still, this problem has been largely overcome by using very thin polyethylene film as a wrapping material.
• This film is wrapped around the moss grass so that it does not leave any opening, which would allow moisture loss from the moss grass.

The advantage of air layering:

• It allows air transfer, but practically no moisture can escape through it.
• Air layering may be done in the spring or rainy season. Rooting often occurs within a month or so under all favorable conditions.
• The rooted layers may be severed from the mother plant and planted in the nursery under a shaded place until established in the field.

Cares taken for Propagation of Hibiscus – What to pay attention to when propagating Hibiscus

Potting Mix:

• Opt for a well-draining, slightly acidic potting mix. Add perlite or vermiculite for additional drainage.
• A commercial mix specifically formulated for Hibiscus can also be used.

Necessary Light required for propagated plant:

• Hibiscus thrives in bright, indirect sunlight.
• Too much direct sun can scorch the leaves, while too little can hamper growth.
• A south-facing window with sheer curtains would be ideal.

Water needs of propagated Hibiscus:

• Water deeply when the top inch of soil feels dry.
• Avoid overwatering, as this can lead to root rot.

Humidity required by propagated plant :

• Moderate humidity levels should be ma. Misting the leaves regularly or placing the pot on a pebble tray filled with water can help.

Fertiliser needed for growth:

• A balanced fertilizer should be used.
• Diluted to half of the strength during the growing season (spring and summer). Avoid fertilizing during winter.

Temperature required for growing:

• Hibiscus prefers warm temperatures between 65-80°F (18-27°C).

Advanced technique in the propagation of Hibiscus:

Seed Propagation in Hibiscus:

• Hibiscus can be propagated from seeds. It is a lengthy process, and true to type can not be achieved when seeds are used as a propagation material.

Grafting technique in the propagation of Hibiscus:

• This advanced technique allows you to combine desired traits from different hibiscus varieties onto a single rootstock.

Pruning of propagated Hibiscus:

• Pruning encourages bushier growth and more blooms.
• Pinch off new growth tips and prune older branches to maintain the desired shape.

Conclusion:

The cuttings treated with high concentrations of IBA, the semi-hardwood cuttings, and cleft graftings performed the best regarding rooting and survival performance.

Increasing the quality of planting material of Hibiscus, cutting, and grafting are the easy propagation methods for developing the hibiscus plant as soon as possible.