Dragon trees do not require a great deal of pruning unless you are growing them indoors or you wish to trim off shoots for starting new plants. If you are growing an indoor dragon tree, pruning will become a necessity to keep your plant from reaching an unmanageable height. Pruning can also include trimming the roots when the plant becomes rootbound.
Trimming to reduce height or to obtain cuttings
If not cut, dragon trees tend to grow upward to a single pom-pom of long, narrow leaves at the top of the tree. As a rule, they do not become messy or out of control, but they can grow too tall for indoors.
Pruning is best done in mid-spring or early summer to give the parent plant plenty of time to recover during optimal growing season. To trim the tree, use a sharp set of pruning shears to cut the main stem at a 45-degree angle slightly below the desired height. If you are trimming a large, outdoor tree, you might need to use a pruning saw. Always use a sharp implement to make the cut.
The tree might look a bit odd for a while, but in a month or two it will put out two new branches at the location where the it was trimmed. For a bushier look, you can let the new limbs grow out, and then prune each of those so they will, in turn, produce double shoots.
The pieces that are trimmed away can be used as single shoots for sprouting or even cut into pieces to obtain more than one new plant. When rooting more than one piece from the original plant, be sure to place the piece so that it is oriented in the same direction in which it originally grew.
Trimming to Relieve Roots
Dragon trees tend to grow to the size of their pot. Therefore, if you wish to restrict the growth of an indoor tree, you can allow it to become a little root bound. The roots will coil around inside the pot. The tree’s growth will slow or stop. When the pot becomes too full of root, you have the choice of placing the plant in a larger pot or trimming a little off the root. The root will coil somewhat like a spring.
Gently remove the plant from the pot and allow the root to spring down. Trim off a little of the excess root. Like the upper trimmings, you might have some success growing a new plant by placing the trimmed root into a new pot.
Trimming away Dead Leaves or Limbs
Although dragon trees are very hardy plants, sometimes they can develop problems. The cause is often overwatering, but the trees are also subject to scale, mealybugs, thrips, and spidermites. The first step is, of course, to stop any insect infestation. The second is to trim away damaged limbs or leaves.
If a limb is damaged, cut off the damaged part behind the dead or damaged area. As when trimming for height or to obtain cuttings, cut the wood at a 45-degree angle using a sharp set of pruning shears or a sharp pruning saw. This minimizes the damage and shock to the plant.
Disposing of Damaged or Diseased Limbs
If possible burn the damaged or diseased plant parts. If burning is not an option, place the plant material in a plastic bag, spray the material with an insecticide, and seal it before hauling it to a disposal site. The goal is to avoid infecting other plants or contaminating the environment with toxins.
Trimming Dead Leaves
Lower leaves in the leaf pom-pom can sometimes wilt or die. Often this is simply natural attrition, but it can also be in response to improper watering, disease or bug infestation. Use a sharp pruning tool or scissor (depending upon the size of the plant) to remove the dead growth.
In summary:
Healthy pruned material can often be used to start new plants. These trimmings can be either from the crown of the tree or from the roots. If the plant is trimmed because of a problem, then that material should be disposed of in a way that will avoid infecting other plants.
Whether trimming small potted plants or trimming large, outdoor plants, always make the cut at a 45 degree angle using a sharp cutting tool.