How To Propagate Crape Myrtle Trees

Crape myrtle trees are a beautiful and popular addition to any landscape. They are known for their showy flowers, which come in a variety of colors, and their attractive bark. Crape myrtles are also relatively easy to care for, making them a good choice for gardeners of all levels. If you are interested in adding a crape myrtle tree to your landscape, you can propagate them yourself from cuttings. This is a relatively easy process that can be done with a few simple tools.

The best time to take cuttings from crape myrtle trees is in the late summer or early fall. At this time, the wood is mature and has hardened off, which makes it more likely to root successfully. To take a cutting, select a healthy branch that is about 6 to 8 inches long. Make sure the branch has at least two or three leaves. Use a sharp knife to cut the branch from the tree, making a clean, angled cut just below a leaf node. Remove the leaves from the bottom half of the cutting, and then dip the cut end in rooting hormone. This will help to promote root growth.

Once you have taken the cuttings, you need to plant them in a well-draining potting mix. You can use a commercial potting mix or make your own by combining equal parts peat moss, perlite, and vermiculite. Water the potting mix until it is moist, and then make a hole deep enough to accommodate the cutting. Insert the cutting into the hole, and then firm the soil around it. Water the cutting well, and then place it in a warm, sunny location. Keep the potting mix moist, and in a few weeks, the cutting should begin to root. Once the cutting has rooted, you can transplant it into a larger pot or into the ground.

Air Layering

Air layering is a technique that allows you to root a new crape myrtle tree from a branch of an existing tree. This method is particularly useful for propagating cultivars that are difficult to root from cuttings. Here’s a detailed guide to air layering crape myrtle trees:

Materials you’ll need:

Sharp knife or pruning shears
Moist sphagnum moss or potting mix
Plastic wrap or aluminum foil
String or twine

Steps to air layer crape myrtle trees:

Choose a healthy branch that is at least 1/2 inch in diameter and free of disease. The branch should also be located in a spot where you can easily work on it.
Remove the leaves and small twigs from a 4- to 6-inch section of the branch. This will expose the bark and promote rooting.
Using a sharp knife, make two parallel cuts around the branch, about 1 inch apart. Connect the two cuts with a downward cut to create a T-shaped incision. Take care not to cut into the wood too deeply.
Carefully peel the bark and a thin layer of cambium (the green tissue beneath the bark) away from the branch. This will expose the xylem (the woody tissue that transports water and nutrients). Be careful not to damage the xylem.
Wrap the exposed xylem with moist sphagnum moss or potting mix. Secure the moss or potting mix in place with plastic wrap or aluminum foil.
Tie the plastic wrap or aluminum foil tightly around the branch, above and below the moss or potting mix. The wrap should be tight enough to hold the moss or potting mix in place, but not so tight that it cuts off the circulation.
Keep the moss or potting mix moist by watering it regularly. Roots will start to develop within 6 to 8 weeks. Once the roots are visible, you can remove the plastic wrap or aluminum foil and carefully cut the layered branch from the parent tree.
Pot up the rooted branch in a well-draining potting mix and place it in a warm, sunny location. The new crape myrtle tree should be mature enough to transplant into the ground in one to two years.

Grafting

Grafting is a technique used to combine two separate plants, creating a new plant that possesses the characteristics of both parents. In the case of crape myrtles, grafting is a highly effective method of propagation, as it allows for the preservation of desirable traits and the creation of new varieties.

There are several different grafting techniques that can be used with crape myrtles, including cleft grafting, whip and tongue grafting, and budding. The most common method is cleft grafting, which involves splitting the rootstock (the lower plant) and inserting a scion ( a cutting from the desired variety) into the split.

Step-by-Step Cleft Grafting Procedure

To perform a cleft graft, follow these steps:

Step	Description
1	Select a healthy rootstock and a compatible scion.
2	Using a sharp knife, make a clean, vertical cut down the center of the rootstock, approximately 2-3 inches deep.
3	Prepare the scion by making a wedge-shaped cut at the base, about 1-2 inches long.
4	Insert the scion into the cleft of the rootstock, ensuring that the cambium layers of both plants are aligned.
5	Wrap the graft union with grafting tape or waxed string, taking care not to cover the cut surfaces.
6	Place the grafted plant in a warm, humid environment and keep it out of direct sunlight.

Greenhouse Propagation

Propagating crape myrtle trees in a greenhouse provides controlled conditions for optimal growth and development. Follow these steps to successfully propagate crape myrtle trees in a greenhouse:

1. Seed Collection and Preparation

Collect seeds from mature crape myrtle trees in the fall. Scarify or nick the seeds to enhance germination.

2. Sowing and Germination

Sow the seeds in a well-drained potting mix in flats or containers. Maintain a temperature of 70-80°F (21-27°C) and provide ample light for germination.

3. Seedling Care

Water the seedlings as needed and fertilize lightly every few weeks. Provide adequate light and space for the seedlings to develop.

4. Cuttings

Alternatively, crape myrtles can be propagated from semi-hardwood stem cuttings. Take cuttings from healthy plants in the summer.

5. Rooting

Dip the cuttings in rooting hormone and place them in a well-drained potting mix. Keep the cuttings warm and moist until roots develop.

6. Transplanting

Once the cuttings have developed a strong root system, transplant them into individual containers or the greenhouse bed.

7. Grafting

Grafting is another method of propagating crape myrtle trees. This technique involves grafting a desired variety onto a rootstock.

8. Detailed Steps for Grafting

Step 1: Rootstock Selection: Choose a healthy rootstock from a vigorous crape myrtle tree.
Step 2: Scion Preparation: Cut a 3-4 inch (7-10 cm) scion from the desired variety.
Step 3: Grafting: Make a T-shaped cut on the rootstock and insert the scion into the cut.
Step 4: Binding: Secure the graft with grafting tape or a rubber band.
Step 5: Aftercare: Keep the grafted plant warm and humid in a propagator. Remove the tape or band after several weeks when the graft has healed.

Field Propagation

Field propagation refers to the propagation of crape myrtle trees directly in the ground. This method is suitable for large-scale production and is commonly used in nurseries and commercial operations. The following steps are involved in field propagation:

Site Selection: Choose a well-drained planting site with adequate sunlight and organic matter. The soil should be loose and well-aerated.
Propagation Method: Crape myrtle trees can be propagated through root cuttings, stem cuttings, or layering.
Root Cuttings: Select healthy roots from mature trees and cut them into 4-6 inch lengths. Plant the cuttings vertically in the soil, leaving the top half exposed.
Stem Cuttings: Collect stem cuttings from healthy stems in late summer or early fall. Cut the stems into 6-8 inch lengths and remove the leaves from the lower half. Dip the bottom of the cuttings in rooting hormone and plant them in the soil.
Layering: Bend a lower branch to the ground and cover it with soil, leaving only the tip exposed. Roots will develop along the buried portion of the branch, and the new tree can be separated from the parent plant once it has established its own root system.
Planting Depth: Plant the propagated crape myrtle trees at the same depth they were in the nursery or when they were taken from the parent tree.
Spacing: Space the trees according to the desired size and shape of the mature tree. Generally, 6-8 feet of spacing is recommended for most varieties.
Watering: Water the newly planted trees regularly, especially during the first growing season.
Fertilization: Fertilize the trees once a year in the spring with a balanced fertilizer.
Pruning: Prune the trees as needed to remove dead or damaged branches, shape the tree, and encourage flowering.
Pest and Disease Control: Inspect the trees regularly for pests and diseases and take appropriate control measures if necessary.