Purple Robe Locust Tree Growth Rate, Problems, Care

The Purple Robe Locust Tree, also known as Robinia 'Purple Robe,' is a deciduous tree that is indigenous to the eastern and central regions of North America. It is capable of growing in conditions that are unfavorable to the majority of other plant and animal species. U.S. Department of Agriculture hardiness zones 4 through 8 are suitable for the purple robe locust. The purple robe tree is considered invasive because its roots and seeds grow so vigorously.

When fully mature, the purple robe locust tree can reach heights of up to 50 feet and widths of up to 25 feet. It is classified as a medium-sized tree. It develops into an upright, uneven oval shape as it matures. The bark of the tree is deeply furrowed and extremely dark grey that it appears nearly black. The fragrant pinkish-purple blooms on hanging racemes that can reach up to 8 inches in length are produced by the purple robe locust tree in the springtime, typically between the months of May and the beginning of June.

Purple robe tree leaves are around a foot long. Each leaf is composed of 9 to 17 leaflets that are either one or two inches long and grouped in pairs. When the leaves of purple robe trees first come out in the spring, they have a reddish-purple color. They gradually grow to a dark green hue and turn yellow in autumn. The tree's seeds are enclosed in 3 to 4-inch long pods.

Purple Robe Locust Tree Growth Rate

The growth rate of a purple-robe locust tree is between 2 and 3 feet each year, and it can reach a full height of 40 to 50 feet, with a width of approximately 30 feet. The pinnate leaves have a bronze-red color when they first emerge in the spring, then change to a blue-green color over the summer, and finally, become yellow in the fall. The sweet-smelling flowers bloom for 10 days in late spring. Then, purple-brown, leathery seed pods 4 inches long stay on the trees all winter. Under the tree, grass can grow because of the tree's tight canopy and short, crooked branches, which create a medium amount of shade.

Purple Robe Locust Tree Problems

Some of the pest problems with "Purple Robe" are substantial, while others are not. Both the locust borer, which can kill the tree, and the locust leaf miner, which can cause the leaves to become brown, can infest the tree. Aphids, whiteflies, worms, and scale insects can all pose a threat to this tree, but they are usually less problematic.

If there is a need for treatment, apply a pesticide that is indicated for these pests, such as Dursban, Permethrin, or Talstar, or an insecticidal oil, and follow the instructions on the label for the appropriate dosage. If you see an increase in adults, spray the lower branches of trees and shrubs with an insecticide.

Purple Robe Locust Tree Care

Once well-established, the Purple Robe Locust tree has excellent drought resistance and is simple to cultivate. It is important to remove any undesirable root suckers as soon as possible to prevent them from becoming invasive. It is vulnerable to the attack of the locust borer as well as other kinds of insect pests. The tree may grow in the partial shade even though it prefers full sun.

Frequently Asked Questions (FAQ's)

What are the Pros and Cons of Purple Robe locust tree?

The Purple Robe Locust is a sturdy, quickly growing shade tree with strands of deep pink flowers in the spring that are both intensely fragrant and incredibly gorgeous. This tree is a genuinely distinctive shade tree that has recently gained popularity. It is highly adaptable to all soil types. It is, however, susceptible to several insect infestations, such as locust borer. If necessary, use pesticides like Talstar to get rid of the infestation.

Is Purple Robe locust invasive?

Due to the rapid growth of its roots and seeds, the purple robe tree is called invasive. The purple robe locust tree has the potential to grow up to 50 feet tall and up to 25 feet wide when fully grown.

Is the Purple Robe locust tree poisonous to dogs?

According to the American Society for the Prevention of Cruelty to Animals (ASPCA), honey locust and carob trees are safe for canine consumption, however black locust and other species of Robinia are considered to be hazardous.

How to Propagate Purple Robe Locust tree?

Even in nutrient-poor soil, these trees thrive and proliferate swiftly. Once fully grown, they can grow up to 40 to 50 feet tall and 30 feet wide. It can be propagated by taking cuttings from the roots or by cutting shoots from the tree.