Cypress trees are heritage trees that provide all-year-round color in the garden and bold statements on the landscape.
Whether grown in borders or containers, these long-lived trees are highly valued for their versatility. From living screens to focal points, no garden is complete without at least one variety of cypress trees.
However, taking the right action is essential if you’ve noticed your cypress tree turning brown and becoming unsightly.
Many gardeners have faced this challenge. Fortunately, though, reviving a browning cypress tree is often possible with the right care and attention.
In this blog, I will explain why cypress trees take a turn for the worse and provide practical step-by-step solutions to help restore them to health. From best watering practices to tackling pests and diseases, this guide will provide all the support you need to revive a cypress tree that is turning brown.
Why Are My Cypress Trees Turning Brown?
Cypress trees turning brown can signify several potential problems, ranging from environmental stressors to pests and diseases. These are some of the likely common causes:
Watering Issues
Cypress trees need adequate moisture. If they don’t get enough water, the roots cannot provide nutrients for growth.
All cypress trees generally grow best in moist to damp soil that drains away. Soggy soil or areas that hold onto water for periods after rainfall are the worst kind and will lead to serious problems that can affect the health of the root system. This, in turn, will affect the tree’s growth and can be a major cause of cypress trees turning brown.
Excessive water can also be harmful, leading to root rot. This condition causes the roots to literally drown and be unable to absorb nutrients and water, resulting in browning needles, especially in Leyland Cypress trees.
However, the exception is the Bald Cypress, which can thrive in water-retentive, moist, free-draining soil.
Pest Infestations
Reviving a cypress tree is tricky when pest infestation occurs.
Spider Mites feed upon the vital sap of a cypress tree and weaken it. This causes the foliage to turn brown and appear dusty or sandy. Severe infestations can even cause the tree to die off completely. Apart from telltale signs of brown foliage, look out for what appears to be fine webbing on the tree. This will indicate a large-scale infestation that needs prompt treatment with organic insecticides.
Bagworms are the caterpillars of the hairy moth that form a protective silken bag that hangs from tree branches. The bag is often mistaken for pine cones but contains hundreds of eggs that hatch into larvae. Each larva produces a strand of silk that enables it to travel with the wind to new food sources. Early treatment is essential with so many airborne hungry mouths wanting to feed.
The best time to inspect for and remove bagworms is from late autumn to early spring. This is before they start to hatch in May and become airborne.
For small infestations, handpick the silken bag from the tree and leave it in a deep bucket for the birds to feed upon. This will promote a natural form of pest control by attracting more birds to the area. For large infestations, chemical insecticides will need to be applied. This is best done in the evenings when there is less chance of harming pollinating insects.
Diseases
Seiridium Canker or Cypress Canker as it is sometimes referred to, is a fungal disease characterized by sunken cankers on branches and trunks. It causes lower branches to turn brown and die back before spreading to the top canopy.
It’s more common in Leyland cypress and very noticeable because it totally blights one side of the usually shaded tree. It can also affect Italian and Montery cypress.
This fungal disease will thrive in wet conditions, providing the ideal environment for the spores to grow.
Infected branches will need to be removed. Then, the tree must be pruned to allow more light and air to circulate from the canopy down to the lower branches.
For younger or newly planted trees that present signs, check that they have been adequately watered. Trees that are water-stressed are usually more susceptible to canker diseases.
Phytophthora Root and Crown Disease are caused by soilborne pathogens that cause distinctive signs of red or yellowing leaves and wilted growth. It rarely affects mature trees, being more common in newly planted or young cypress trees. The cause is usually poor drainage.
The chances of reviving a cypress tree with these issues are slim; the only treatment method is a fungicide. If the tree does not survive, it must be removed and all parts destroyed. The tree’s soil should also be removed to a depth and width beyond the roots.
Improve the drainage if necessary and avoid planting any other cypress variety of trees on the same site.
Needle Blight is a nonparasitic disease that causes the leaves to turn brown. It usually only affects growth in the second year and is caused by incorrect watering. Either too much or too little.
As a result, the tree’s feeder roots are affected, which leads to a poor uptake of water and nutrients. This lack of uptake causes brown patches of growth on the affected side.
In this instance, the best way to revive the tree is to ensure the right amount of water and an antifungal treatment.
Nutrient Deficiencies
Iron or magnesium deficiency can cause chlorosis and browning of the foliage, particularly if the soil pH is too high (pH > 7.0), restricting nutrient uptake.
In general, mature cypresses will obtain enough nutrients from their surroundings. A thin mulch of compost should be applied every couple of years, providing an adequate top-up of any lacking nutrients.
Newly planted or younger trees will require applied fertilizer in spring and again in summer. For the first growing season, apply a fertilizer with a root stimulator. Then, a balanced fertilizer will be adequate for the next two growing seasons until the roots are well established.
Environmental Stress
- Drought Stress: Prolonged drought conditions can lead to browning, particularly in cypresses that are not drought-tolerant.
- Winter Burn: Cold winds and freezing temperatures can damage foliage, leading to browning, especially in evergreen cypresses.
- Heat Stress: Excessive heat can stress trees, particularly if newly planted in areas without adequate water or in unsuitable soil conditions.
Poor Planting Location
Always consider the eventual size of your tree and any nearby plantings that could be affected. Removing or pruning a mature, poorly located cypress tree can be expensive and inconvenient.
Once removed, you might not be able to plant where any remains of roots are left. This would be more so if it had been removed due to a fungal disease. The ground might also take a while to settle and require leveling off.
Avoid locations with poor soil drainage, inadequate sunlight, or are likely to restrict root growth, as this can all cause browning as a sign of stress. For more information, refer to where the cypress tree grows the best.
How To Revive A Cypress Tree Turning Brown?
In the first instance, decide if it is worth saving. If it needs pruning to remove large areas of brown patches, will this spoil the overall shape and symmetry? Lopping off the canopy can dramatically alter the tree’s shape, too.
It is worth considering whether it is the one focal point in your garden or a main feature of the landscape. Will it be as aesthetically pleasing once all the brown growth has been removed? Or will it be better to remove and replant another cypress tree?
Reviving a cypress tree that is turning brown will involve identifying the root causes and how best to resolve them. You might be able to treat the problem yourself, or you might need the services of a tree specialist.
To help you decide, we have compiled a few steps you can follow on how to restore the health of your cypress tree:
Diagnose the Problem
Are there signs of pests, diseases, or physical damage, such as broken branches or brown growth? Check for insects, sticky residues, or unusual markings on the trunk and foliage.
Also, inspect the soil and drainage. Cypress trees dislike waterlogged soil but shouldn’t be allowed to dry out.
Is the tree planted near underground drains? A burst pipe could be causing water-logged soil at a deeper level.
Consider recent weather conditions, such as drought or excessive rainfall, and check if the tree might be suffering from heat stress or winter burn.
Adjust Watering Habits
Ensure the tree, especially if newly planted or young, receives consistent moisture, especially during dry periods. Watering deeply but less often is best, as this will encourage deep root growth over shallow roots.
The watering needs can also depend on the season, the rate of growth, and unusual weather patterns, such as prolonged dry or wet periods. Wind can also have a very drying effect on soil.
If the area is waterlogged, improving drainage might be necessary by adding organic matter to the soil or creating a drainage pathway to help excess water escape.
A drainage pathway involves digging a trench and filling it with gravel, hardcore, or similar materials. The pathway should slope away from the waterlogged area.
Alternatively, a drainage pipe can be used in the trench and backfilled with soil.
Control of Pests and Diseases
Treat the tree with appropriate insecticides if pests like spider mites or bagworms are identified. Neem oil and insecticidal soap are natural products that have proven very effective. Neem oil can also help prevent fungal spores from developing and protect against certain fungi.
Be especially vigilant about bagworms when trying to revive a cypress tree. When hatched, the larvae travel on airborne silk threads, enabling them to quickly spread to all areas of your garden if left unchecked.
Prune branches with any heavy infestations. Then, either remove the prunings from the site or burn them. Don’t be tempted to put them out for composting, as there will be a real risk of re-infestation.
Note: Neem oil is not permitted in Canada or the United Kingdom due to associated health risks. It is advised to check with your local authority before purchasing and always follow recommended guidelines.
For fungal diseases like Seiridium canker or Cypress canker, prune away affected branches to prevent spread and sterilize your tools between cuts. Fungicides can be applied, but they are often more effective as a preventative measure rather than a cure.
Dispose of all affected branches by removing them to a designated waste area or burning them.
Nutrient Management
Conduct a soil test first to check for nutrient deficiencies. Cypress trees turning brown may lack essential nutrients. In some cases, adding iron and soil sulfur can help revive your cypress to full color.
Based on the soil test results, apply a suitable cypress tree fertilizer like 18-18-8 (NPK). Avoid high-nitrogen fertilizers, which can exacerbate fungal issues, and instead choose a balanced or micronutrient-rich formula.
Pruning
Careful pruning of cypress trees, especially dead or dying branches, can help reduce the tree’s stress load. Pruning improves air circulation and allows light to reach dense foliage. It also removes potential sources of disease infection and pest infestation.
When brown branches have been cut away, it allows more sunlight to reach the surrounding foliage. The sunlight will encourage more growth that, in time, will help to cover areas that have been cut away.
Pruning also allows more air to circulate throughout the denser foliage. This helps keep the foliage dry and makes it more difficult for fungal diseases to take hold.
Mulching
Add a layer of mulch around the tree’s base (but not touching the trunk); this will help retain soil moisture and regulate soil temperature. It will also keep weeds at bay for newly planted or young trees.
Here are ten steps to follow if weeds grow in the mulch bed.
Monitor and Maintain
Continue monitoring the tree’s health, looking for positive signs of new growth or further signs of decline. Also, regularly check for pests and diseases.
Correct watering is crucial, especially for young trees. It is the key to preventing and addressing many of the problems covered in this article.
Types Of Cypress Trees More Prone To Browning
Certain types of cypress trees are more prone to browning due to environmental pollution, pests, diseases, and poor location.
Leyland Cypress (x Cupressocyparis leylandii)
Browning Issues: Leyland cypress is particularly prone to browning, especially from fungal diseases like Seiridium canker and Botryosphaeria (Bot) canker. These diseases cause branches to die back, leading to extensive browning if not treated at first sight. Leyland cypress is more prone to drought stress and root rot, which can result in visible browning.
Italian Cypress (Cupressus sempervirens)
Browning Issues: Italian cypress is particularly susceptible to cypress canker, a disease that leads to severe browning and dieback. The tree is also vulnerable to root rot in poorly draining soils, contributing to the foliage’s browning.
Arizona Cypress (Cupressus arizonica)
Browning Issues: This type of cypress can experience browning due to Phytophthora root rot, particularly in wet conditions. Spider mites, which thrive in dry, hot environments, can also cause the foliage to brown.
Bald Cypress (Taxodium distichum)
Browning Issues: Bald cypress is a deciduous conifer that naturally turns brown, red, and orange as it loses its needles in the fall. However, it can also show browning due to excessive drought or waterlogging, which stresses the tree and affects its health. Yellowing foliage before the fall is a sign that the tree is receiving too much water. In contrast, wilting foliage suggests the opposite: not enough water.
Monterey Cypress (Cupressus macrocarpa)
Browning Issues: This tree is susceptible to the cypress tip moth, which can cause browning and dieback of the tips of branches. Monterey cypress also faces threats from Phytophthora canker, which leads to branch browning and decline. It is also sensitive to environmental pollution.
Are Cypress Trees Evergreen?
Most cypress trees are evergreen, meaning they keep their foliage and remain green all year round. Different varieties have different shades of green, from light to dark hues.
Some also have yellow or more bluey-grey foliage. This versatility makes them popular choices for landscaping and privacy screens, providing year-round color and structure to gardens and outdoor spaces.
However, there is an exception: the bald cypress (Taxodium distichum). Unlike other cypress species, the bald cypress is deciduous, which means it sheds its needles annually in the fall.
Its needles are green during the growing season but put on a spectacular autumn show in the fall. This is when they turn rusty orange and red before falling off as the season changes to winter. This unique trait sets the bald cypress apart from its evergreen relatives.
Final Words
Here at Gardens’ Yards, we hope you will find this article useful in enabling you to revive a cypress tree successfully. Given the right care and attention, cypress trees will sometimes grow for many years, even hundreds of years!
