Honey locust trees (Gleditsia triacanthos) are common landscape trees, recognized for their distinctive, delicate foliage and adaptability. These deciduous trees have gained a reputation for their ability to establish and grow quickly in various environments. This article explores honey locust growth patterns and influencing factors.
Understanding Honey Locust Growth Rates
When discussing tree growth, “growth rate” refers to the increase in height and spread over a year. Honey locusts are classified as fast-growing trees. Under optimal conditions, they can add 18-24 inches of height annually. This rapid development means a young honey locust sapling can mature into a substantial tree, providing shade and visual interest. They can reach mature heights of 30 to 70 feet, with some specimens growing as tall as 100 feet.
Factors Influencing Growth
Several environmental and genetic factors impact how quickly a honey locust tree grows. Soil conditions play a role, with honey locusts performing best in well-drained, moist soils that have a pH between 6.0 and 8.0, though they tolerate a wider range, including acidic, alkaline, and salty soils. While they tolerate drought once established, consistent moisture, especially for young trees, supports robust growth. Full sunlight is important; they require at least six hours of direct sun daily for optimal development and canopy growth, struggling in dense shade.
Climate and hardiness zones affect growth, as honey locusts are hardy in USDA zones 3 to 9, but extreme temperatures can influence their growth cycle. Southern varieties planted in northern regions may experience frost damage due to prolonged growth into colder periods. Pests and diseases, such as spider mites, gall midges, webworms, and cankers, can hinder growth by stressing the tree. The genetic makeup of the tree, including specific cultivars like thornless or seedless varieties, can lead to differences in their inherent growth potential and mature size.
Promoting Optimal Growth
To encourage healthy and vigorous growth, proper care from planting is beneficial. Selecting a site with full sun and well-drained soil is important for initial establishment. During the first year after planting, regular deep watering, about once per week, helps establish a strong root system. Once established, honey locusts are drought-tolerant, but supplemental watering during prolonged dry spells can still be beneficial.
Applying a balanced fertilizer in the spring can support growth, especially if soil nutrients are lacking, but over-fertilization should be avoided. Mulching around the base helps retain soil moisture, regulate soil temperature, and suppress weeds, all of which contribute to better growing conditions. Protecting young tree trunks from damage by lawnmowers or other equipment is important, as injuries can stress the tree and make it more susceptible to issues.
Managing Established Honey Locusts
Once honey locusts are established and growing vigorously, management shifts towards maintaining their structure, health, and form. Pruning is an important practice, best performed in late winter or early spring before new growth begins, or in late fall after leaves drop. This allows for the removal of dead, damaged, or crossing branches, which can prevent canker development and improve air circulation within the canopy. Structural pruning during the tree’s younger years helps establish a strong central leader and balanced branching, contributing to its long-term stability.
For varieties that produce thorns, managing them is a consideration, though many modern cultivars are thornless. While honey locusts are adaptable, their rapid growth can lead to issues like overshading or shallow root systems that might interfere with lawns, especially if stressed. Long-term monitoring for signs of stress, such as thinning canopies or branch dieback, or for the presence of pests like the honey locust pod gall midge, can help address potential problems promptly and ensure the tree continues to thrive.