Hibiscus Grafting, Pruning and Training
Today, we are discussing with Hibiscus Grafting Methods, Pruning Procedure, and Training Process.
Hibiscus is also called as China rose. Some information about Hibiscus:
- Hibiscus or rose mallow is a plant. The flowers and other parts of the plant are used to create medicines. Hibiscus flowers in whole or powdered form are often used as natural dying agents for cosmetics, fabric, & foods.
- The hibiscus tree produces trumpet-shaped flowers that come in white, yellow, peach, pink, red, purple, blue or lavender color. When you care for a hibiscus, you must remember that hibiscus flower best in temperatures between 60-90°F.
- When hibiscus is in their blooming stage, they require a large quantity of water. The Hibiscus will need daily watering in warm weather. In the winter, water your hibiscus when the soil is dry to the touch.
- The hibiscus plant is an evergreen shrub, growing to a maximum of 10 m in the wild. Its bark is light-grey, easy to peel & smooth. Hibiscus leaves are ovate, simple & 8 to 10.5 cm long. They are spirally given around a long stalk.
- A flower large and showy grows up to 25 cm wide, stalked and arising singly from the upper leaf axils. The five free petals connected at the base may be white, yellow or red in nature. Sepals are connected in a five-lobed cup with an epicalyx of five to seven lobes.
- Soil pH for growing hibiscus is about 6 to 7. The hibiscus flower is edible and has a tangy citrusy taste. The flower can be used to create a natural dye or food coloring. Hibiscus is the national flower of South Korea, Malaysia & Haiti.
- Hibiscus has a green color, lanceolate leaves with toothed edges. These leaves are alternately arranged on the branches. Hibiscus extends large, trumpet-shaped flower without a scent.
- Hibiscus is native to warm temperate & tropical regions. It tends to develop in wet or swampy areas. There are about 220 different species of hibiscus in the world, and every variety differs in size, shape, and color.
Propagation of Hibiscus:
Propagated hibiscus in different ways;
Propagating Hibiscus by cuttings:
Propagation from Hibiscus Cuttings Both hardy & tropical hibiscus are propagated from cuttings. Hibiscus cuttings are generally the preferred way of propagating hibiscus because cutting will grow to be an exact copy of the parent plant. When using hibiscus cuttings to propagate hibiscus, begin by taking the cutting. The cutting must be taken from new growth or softwood. Softwood is branched on the hibiscus that has not yet developed. Softwood will be pliable & often has a greenish cast. You will generally find softwood on hibiscus in spring or early summer.
The hibiscus cutting must be four to six inches long. Remove everything but the top position of leaves. Trim the bottom of the hibiscus cutting to be cut below the bottom leaf node. Dip the bottom of the hibiscus tree cutting in rooting hormone. The next step for propagating hibiscus from cuttings is to position the hibiscus cutting in well-draining soil. Make sure the rooting soil is thoroughly wet, and then stick a finger into the rooting soil. Place the hibiscus cutting into the hole & backfill it around the hibiscus cutting. Place a plastic bag over the cutting, production sure that the plastic does not touch the leaves. Position the hibiscus cutting in partial shade. Make sure the rooting soil stays damp until the hibiscus cuttings are rooted. The cuttings must be rooted in about eight weeks. Once they are rooted, can report them in a bigger pot. Be warned that hibiscus will have a lower rate of success than hardy hibiscus, but if start several cuttings of the tropical hibiscus, there is a good possibility at least one will root successfully.
Read: Rose Plant Pruning Methods.
Propagating Hibiscus from Hibiscus seeds:
While both tropical hibiscus and hardy hibiscus can be propagated from hibiscus seeds, typically hardy hibiscus is propagated this way. This is because the seeds will not grow true to the parent plant & will look different from the parent. To develop hibiscus seeds, start by nicking or sanding the seeds. This helps to get moisture into the seeds & improves germination. The hibiscus seeds can be nicked with a knife or sanded with a bit of fine grain plain sandpaper.
After you have completed this, soak the seeds in water overnight. The next phase in propagating hibiscus from seeds is to place the seeds in the soil. The seeds must be planted twice a deep as they are big. Since hibiscus seeds tend to be small, you can use the tip of a toothpick to make the hole. Kindly sprinkle or sift more soil over where you planted the hibiscus seeds. This is better than backfilling the holes because will not inadvertently push the seeds deeper. Irrigate the soil once the seeds are planted. You must see seedlings appear in one to two weeks, but it can take up to four weeks.
Grafting Methods of Hibiscus:
Grafting is plant propagation by physically joining two pieces of plant tissue together in such a way that they will unite & subsequently grow and develop as one composite plant. The top is known the scion which carries most of the desired characteristics of the future composite plant. The bottom is the rootstock which can allow for the environment, disease resistance, dwarfing & other variances from the normal mother plant.
This graft is also known as the side wedge graft & is probably the graft most commonly used for hibiscus. A piece of scion wood, preferably not longer than 7 cm or 3 in with two or more eyes, is cut & sharpened to a pointed wedge. This wedge must be cut with one even stroke on every side. A slanting downward cut equal in length to the scion cut is completed into the rootstock at an angle of about 60°. The wedge is inserted with the buds position up.
After matching the cambium layer on at least one side, the graft is then tightly bound with grafting tape & the union sealed with grafting tar or mastic. Trim off any eyes on the understock below the graft to prevent these from shootings, & trim a few centimeters from the top of the plant, leaving enough leaves to enable the plant to recover rapidly. Once the scion has begun to grow & the first leaves are beginning to mature, then the top section of the rootstock is cut off as close to the graft as possible. Plants that have been grafted come away a lot faster if placed under glass or under optimum conditions. Side grafts take much better when the plants are growing vigorously, generally in summer and autumn, although they can be ready at other times of the year except winter, unless under glass.
A smooth, shallow cut about 25 mm long is prepared diagonally into the rootstock. At the base of this cut, a second short inward & downward cut is made, intersecting the first cut, so as to eliminate the piece of wood and bark and leave a small notch in the rootstock. On the scion wood, create a long matching cut on one side and a very short one at the base on the opposite side. Fit the scion into the notch on the rootstock similar the cambium layers at least on one side, with the notch at the bottom of the rootstock forming a cap to cover the last part of the scion wood. Bind tightly with grafting tape & apply grafting tar. This is known as a chip graft & seems to provide a good percentage of `takes’. Cut off the rest of the rootstock once the scion has produced mature leaves.
While it is probably to place many grafts of different varieties on a single large bush. The growth patterns of the varieties grafted are identical; if there are various growth habits in the scions, the stronger the major plant will prevail. However, it is possible to place many grafts on the one bush & remove them once they have taken either by air layering or by cutting them off & treating them as cuttings.
Top Wedge Grafting:
This Top wedge grafting method is used widely in the propagation of tropical fruit trees, especially avocado. The base of a multi-node scion, from which leaves greater than 0.4 inches long have been removed, is cut with a tapered wedge that is put into a vertical cleft cut down the center of a decapitated under a stock plant. The scion stock connection is wrapped with a budding rubber. A polyethylene bag, the inside of which has been sprayed lightly with water, is then placed over the scion & ﬁxed with a twist tie about 1 inch below the scion stock junction. Post-grafting management of the grafted plant involves rising it under about 70% shade on a greenhouse bench.
This process is used by most commercial growers as it provides a better union between the scion and the rootstock. It is mostly done in spring when ample grafting material is available from prunings. The rootstocks are grown in small, easy to handle pots, 7.5 to 10 cm, until about pencil thickness in diameter. The scions are cut from wood the same diameter, or as close as possible, & are made no longer than 7 cm with at least two eyes. The rootstock is cut off about 10 cm above the pot & all the eyes removed. A cut is then completed right in the center of the rootstock about 2.5 cm deep and the scion cut to create a matching wedge shape. The wedge is placed in the cut in the rootstock, tied with grafting tape & sealed with grafting mastic. If placed in a glass-house these grafts initiate to shoot out within a few weeks.
There is a difference to this which gives the grafter an even better union. After the top of the rootstock has been removed & the cut made down the middle, the bark is peeled back on one side. The section of white wood now visible is cut out for a length of about 2.5 cm, & the scion wedge, cut less acute than before, is placed beside the remaining white wood with the cambiums matching. The bark is placed beside the other side of the scion. This union is more uniform & is advised when grafting wood over 13 mm thick.
Tip Grafting or Saddle Grafting:
Tip Grafting is almost the same as the wedge graft except that it is done on green tip wood. Cut a scion with several eyes below the growing tip, which is removed to prevent wilting, & sharpen the bottom of it to a wedge. Cut the top of the rootstock & splice it down the center as for the wedge graft. Insert the wedge into the rootstock matching the cambium & bind tightly. Covering with a plastic bag will stay the green wood from drying out. Use a stick or stake in the pot to hold the plastic away from the scion, and a rubber band around pot & bag to keep the moisture in. Place the plant in the shade for about a week & gradually harden off, removing the bag before the plant is placed in the sun. This process of grafting is mainly done during the late summer or early autumn just as the green wood begins to firm. This graft can be reversed, the rootstock being sharpened to a wedge and inserted into a corresponding notch cut in the scion. The advantage of this technique is that moisture is kept out better & the downward flowing sap in the cambium helps the scion to callus faster. This method is also called saddle grafting.
Soil at the bottom of the hole must be loose for good drainage. The plant must sit at the same level it was before being moved. Place the plant in the hole at the right stage, and then fill three-quarters of the hole with soil. Water & tamp down lightly to remove any air pockets that may be present. Drive in stakes to secure the plant, and fill the remaining part of the hole with well-mixed soil or a mixture of soil & peat moss.
Plant in spring, summer, or fall, spacing plants three to six feet apart. Dig a hole only as deep as the root ball & 2 to 3 times as wide. If the soil is in very poor condition, amend the soil you’ve removed from the hole with a small amount of compost. Carefully remove the plant from the container & set it in the hole. Fill the whole half full of soil, and then water it well to settle the soil & eliminate air pockets. Let the water drain, then fill the remainder of the hole with soil & water thoroughly.
What is Pruning?
Pruning is defined as “trimming or cutting branches to improve growth & appearance.” Pruning methods used in Hibiscus:
This is pruning of the topmost development tips of branches to encourage a fuller bush. You do this by nipping off the top 1 to 2 cm of green growth. The pinching method works best on younger plants.
As the name indicates, pruning is carried out on selected branches & stems. At no time are other than one-third of all the branches trimmed back. This is generally the best compromise for hibiscus, as it keeps some branches undisturbed & blooming while letting other new branches develop.
Here you cut back all the branches at once down to 2 to 3 nodes per branch. You have to wait a bit before the next flowers come, true, but this generally yields the best, most harmonious plant. If you want to develop a show plant for your garden this is the way to go. At Hidden valley hibiscus the stock plants are pruned this way as a matter of course, as we harvest wood for propagation.
Rejuvenating or Hard Prune:
This is only carried out on old plants with lots of dead wood & scrawny growth. You cut back rather low down, but no lower than one foot above soil level, and remove much larger branches than in a regular pruning. Hard pruning is a drastic quantify for mature plants that aren’t growing or blooming well. It is particularly good for those old plants that are tall with lots of sticks & stems but few leaves and flowers. A hard prune will force the plant to regrow an additional compact, rounded bush.
This means pruning those branches that are undesirable or damaged. Pruning off dead tips or branches that have been damaged by cold is one category of corrective pruning. Another form is cutting off very long stray branches that stick out in unattractive ways or reshaping a lopsided plant. The goal is to prune enough to create a healthy, balanced plant.
Pruning method in Hibiscus:
For hibiscus planted in the ground in very warm climates where winter freezing is seldom a problem, pruning can be completed in the late fall. This forces the plant to put rising energy into roots first, then when spring comes, branches shoot out all over, which means a lot more flowers in the summer.
Pruning is used to shape future growth, invigorate old plants, manage plant size and get rid of diseased & dead wood. While the tropical hibiscus can be pruned any time, probably the ideal is the earliest where the resulting tender new development will be safe from cold damage. For shaping purposes, some growers will prune the longest third of the branches & return in 4 to 6 weeks and prune the next longest third. Only sharp, clean shears must be used. A clean cut should be just above and angled down & away from an “eye” or node. Cutting above outward pointing “eyes” will encourage development in that direction. The new growth resulting from pruning invigorates the plant & will provide a source for many new blooms.
Training begins when a tree is planted & continues throughout the life of the tree. Training a tree properly through its first few years can save many hours of difficult, corrective pruning as the tree ages. Limb positioning is important because it determines whether the branch will generate primarily fruit or vegetation. When branches grow straight up, they produce mostly vegetative growth & very little fruit. By contrast, branches that grow straight out from the tree are very fruitful but generate little new vegetative growth. The perfect limb position is about 30° above horizontal, creating a 60° crotch angle. This allows maximum fruit production while still promoting the development of new wood for future fruiting. In addition, branches having a wide angle between the limb & the trunk, the crotch angle, are stronger than upright branches with narrow crotches. Branches are more easily positioned when they are only 3 to 6 inches long with very soft wood.
Training Young Trees:
Young trees can be trained using pruning methods which will help promote plant health and long life.
The first pruning after trees and shrubs are purchased consists of removing broken, crossing & pest-infested branches. The traditional suggestion of pruning up to one-third of top growth when transplanting to compensate for root loss is no longer valid. Excessive pruning at transplanting reduces leaf area, which decreases the amount of plant energy generated which are needed to create a healthy root structure. When transplanting woody plants, the necessary pruning is the removal of broken or damaged branches.
The central leader of a tree must not be pruned unless the leader is not wanted, as is the case with some naturally low-branched trees or where multiple-stemmed plants are desired. Trees with a central leader, such as Texas red oak, sweet gum, may require little pruning except to eliminate branches competing with the central leader. These competing branches must be shortened. Some pruning can be necessary to maintain the desired shape and to shorten extra vigorous shoots.
The height of the lowest branch can range from a few inches above the ground for screening or windbreaks, to more than seven feet above the ground near a street. Removal of lower limbs is generally completed over a period of years beginning in the nursery & continuing for several years after transplanting until the desired height is reached.
The model in training a tree called “the trashy trunk” refers to this gradual raising of the lowest branches of a tree. Lower branches on the major trunk help create a thicker trunk more quickly. A common mistake in pruning young trees is to strip them of small branches, leaving a tuft of leaves at the top of the tree. This training is incorrect & forms a weak “buggy whip” trunk. Remove lower limbs when they reach one inch in diameter. This prevents permanent scarring of the trunk basis by removing larger limbs.
Another important model in training trees is light versus heavy cuts. This refers to the length of the branch being removed & the desired growth response to that branch. With a young, vigorous growing branch, if the terminal end is lightly cut back, then lateral branching is induced up & down the branch. On the contrary, if this branch is heavily cut back, the one or two buds located just below the cut are forced & grow at a very rapid rate. The importance of this pruning concept lies in the development of bushy, well-shaped trees through light pruning & the often-desired invigorating effect of heavy cuts.
For greater strength, branches chosen for permanent scaffolds must have a wide angle of attachment to the trunk. Branch angles less than 30 degrees from the main trunk effect in a very high percentage of breakage, while those between 60 and 70 degrees have a very low breakage rate. Although some trained hibiscus develops strong trunks, many tree-form hibiscus plants require continuous maintain, so you must keep the stake in place beside the plant.
Read: Growing Marigold.