November 6, 2025
Leyland Cypress trees are one of the most common choices for privacy screens and windbreaks in Southern Maryland. They grow fast, stay green all year, and can turn a property line into a solid, natural wall in only a few years. But when they are not cared for properly, they decline quickly. Branches turn brown, diseases spread through the hedge, and entire sections begin to die off. This guide explains how to keep Leyland Cypress trees healthy in our local climate, how to prevent common problems, and when it is time to call a professional.
What Makes Leyland Cypress Popular Here
Homeowners choose Leyland Cypress because they grow three to four feet per year, tolerate most Maryland soils, and are rarely damaged by deer. They provide instant privacy and reduce noise from nearby roads and neighbors. Their ability to adapt to different yards makes them a standard sight in Calvert, Charles and St. Mary’s counties.
The problem is that fast growth also makes them weak if not maintained. Poor spacing, heavy clay soil, drought stress and lack of pruning make them vulnerable to disease. Many people plant them too close together or never trim them until they are already damaged. Healthy trees begin with proper planting, watering and airflow.
Core Leyland Cypress Care: Watering, Soil, Mulch and Spacing
Leyland Cypress prefers moist but well drained soil. Young trees should be watered deeply once a week during dry periods. Mature trees usually need water only during long droughts. Water at the base, not over the foliage. A two to three inch layer of mulch helps hold moisture in summer and protect roots in winter, but the mulch should not touch the trunk.
These trees are not heavy feeders. Over fertilizing makes them grow too fast and weak. If the soil is poor, use a slow release, balanced fertilizer in early spring. A soil test is helpful before adding anything.
Spacing is one of the most important parts of long term health. Trees planted too close compete for water and nutrients and trap moisture around the branches. This creates ideal conditions for fungal disease. Plant them at least ten to fifteen feet apart if you want a long lasting hedge that can breathe and stay dry inside. Good airflow is one of the simplest ways to prevent issues.
Pruning Without Ruining the Tree
Pruning keeps Leyland Cypress dense, green and healthy. The best time to trim is from early spring to mid summer. Avoid heavy pruning in late fall or winter when new cuts cannot heal before cold weather.
The biggest mistake people make is cutting into old wood. If you cut past the green growth into the brown, leafless wood, it will not grow back and the tree will stay bare in that spot. Only trim current season growth. When shaping a hedge, keep the base slightly wider than the top so sunlight reaches lower branches. This prevents thinning and browning from the ground up.
Dead, broken or diseased branches should be removed as soon as possible. Clean pruning tools with a bleach solution when moving from one cut to another, especially if disease is present. Regular light trimming two or three times per year is better than one heavy cut.
Local Problems: Disease, Bagworms and Root Rot
Even well cared for Leyland Cypress can face issues in Southern Maryland because of humidity, summer drought and heavy soils.
- Seiridium canker is the most damaging disease. It usually attacks trees that are already stressed. Branches turn orange or brown, and the bark may show sunken lesions with sticky resin. There is no chemical cure. The only solution is to prune several inches below the infected spot into healthy wood. If the canker reaches the main trunk, the tree often needs to be removed.
- Bagworms are a common pest. They create cone shaped bags from silk and foliage and hang from branches. As they feed, needles turn brown and trees can become bare. Pick the bags off by hand during winter or early spring before the larvae hatch. If there are too many, a professional insecticide treatment may be needed.
- Root rot appears in areas with poor drainage or compacted clay soil. Trees decline slowly from the top down, foliage turns yellow or brown, and growth stops. Once rot sets in, recovery is unlikely. Prevention is the only real solution. Plant in well drained soil and avoid overwatering.
When It Is Time to Call a Professional
Not every Leyland Cypress issue needs a tree service, but there are moments when doing it yourself isn’t worth the risk. If disease has spread into the trunk, the tree is leaning, the hedge is too tall to trim safely or large branches are dying near your home, it’s time to call a professional. These trees can grow massive, and removing or treating them without the right equipment can cause more damage than good.
Empire Tree Services works with Leyland Cypress trees across Southern Maryland every day. We know the soil, the drainage problems, the summer droughts and how these trees react when they’re stressed. Whether it’s pruning, diagnosing disease, removing a failing tree or keeping a hedge healthy for the long run, we handle it safely and with care for your landscape.
Final note: Leyland Cypress is a fast growing, beautiful tree, but it is only low maintenance when planted and cared for correctly. With proper watering, spacing, pruning and early attention to disease, your hedge can stay green and full for decades.
Frequently Asked Questions
Why are my Leyland Cypress branches turning brown?
Browning can happen for different reasons. Inner foliage turning brown in fall is normal. But if outer branches are browning, especially in large patches, it may be stress, drought, Seiridium canker, bagworms or root rot. Look for signs like resin oozing from bark (canker), silk bags hanging from branches (bagworms) or constantly wet soil (root rot). Early identification makes a difference.
How often should I water Leyland Cypress trees?
Young trees need deep watering about once a week during dry weather to help roots grow down. Mature trees only need water during long dry periods. Always water the soil at the base, not the foliage. Avoid shallow daily watering and avoid soaking roots constantly, because overwatering and poor drainage can cause root rot.
Can a Leyland Cypress recover from canker disease?
If caught early and limited to a few branches, the tree can often be saved by pruning several inches below the infected area into healthy wood. Tools must be disinfected between cuts. If the canker reaches the trunk or multiple main limbs, the tree usually cannot recover and should be removed to protect nearby trees.
What is the correct way to prune a Leyland Cypress hedge?
Prune in spring or early summer while the tree is actively growing. Trim only the green growth and never cut into bare brown wood, because it will not grow back. Shape the hedge so it is a little wider at the bottom than the top. This lets light reach lower branches and prevents browning from the ground up. Small, regular trims are better than heavy cuts once a year.
How can I prevent root rot in Leyland Cypress trees?
Plant in well drained soil and avoid areas where water sits after rain. If your yard has heavy clay, plant on a slight mound to raise the root system. Water deeply but allow the soil to dry slightly between watering. Keep mulch a few inches away from the trunk and avoid constant moisture around the roots. Once root rot is advanced, it cannot be reversed, so prevention is key.
