The Ash tree (Fraxinus excelsior) is a native tree species found throughout the UK and plays a vital role in our natural landscape. Known for its impressive height, strong timber, and distinctive leaves, the Ash tree has long held cultural and ecological significance. However, recent threats, particularly from diseases like Ash Dieback, have raised concerns for its future. In this fact sheet, we’ll cover how to identify an Ash tree, how to care for it, potential threats, and how professional tree surgeons can help maintain these majestic trees.

Characteristics of the Ash Tree

The Ash tree is a large, deciduous tree that typically grows between 15 and 20 meters tall, with some exceptional specimens reaching up to 30 meters. It has smooth, greyish bark that becomes more ridged and cracked as the tree matures. The Ash tree is well-known for its compound leaves, which consist of 5 to 13 leaflets arranged in an opposite pattern. These leaves are dark green in summer, turning yellow in autumn before falling.

One of the most distinctive features of the Ash is its clusters of purple or green flowers that bloom in early spring before the leaves appear. In late summer, the tree produces its characteristic seeds, known as ‘keys’ or winged samaras. These seeds are dispersed by the wind, allowing the Ash tree to spread across the landscape.

How to Spot an Ash Tree

Identifying an Ash tree is relatively easy once you know what to look for. Here are a few key characteristics to help you recognise it:

• Leaves: Ash trees have compound leaves made up of multiple leaflets (usually 5-13). These leaflets are long, narrow, and pointed, with a smooth edge. In autumn, the leaves turn pale yellow before dropping.
• Bark: The bark of a young Ash tree is smooth and grey, while mature trees have a rough, ridged texture.
• Twigs: Ash twigs are relatively thick with a distinctive dark purple-brown colour and opposite branching. The buds on the twigs are large with a characteristic “black” appearance.
• Seeds (Keys): In late summer or early autumn, you will see the winged seeds of the Ash tree. These seeds are elongated and hang in clusters, often spinning as they fall to the ground.

How to Care for an Ash Tree

Ash trees are generally low maintenance, but to ensure they stay healthy, consider the following tips for tree care:

• Watering: Ensure the Ash tree receives adequate water, especially in the first few years after planting. They prefer moist, well-drained soil. Water deeply during dry periods to encourage root growth.
• Pruning: Regular tree pruning helps maintain the shape and health of the tree. Removing dead or damaged branches will prevent diseases from spreading and ensure good air circulation.
• Mulching: Apply mulch around the base of the tree to retain moisture, suppress weeds, and stabilize soil temperature. Keep mulch away from the trunk to prevent rot.
• Fertilising: While Ash trees typically do not require heavy fertilisation, you can apply a slow-release balanced fertiliser in the spring if you notice poor growth or yellowing leaves.

Threats and Diseases to Ash Trees

The Ash tree faces several significant threats, with the most concerning being Ash Dieback (Hymenoscyphus fraxineus). This fungal disease is spreading across Europe and has devastated Ash populations in the UK. It causes leaf loss, dieback of the crown, and eventually leads to tree death. The disease is especially concerning as it affects Ash trees of all ages.

Other threats to Ash trees include:

• Ash Yellows: A disease caused by a bacterium, which affects the tree’s vascular system and causes yellowing of the leaves.
• Honey Fungus: A parasitic fungus that attacks the roots and lower trunk of Ash trees, causing them to weaken and eventually die.

Problems Ash Trees Can Cause Homeowners

While Ash trees are generally hardy, they can pose some challenges for homeowners, especially if they are not properly maintained:

• Falling Branches: Ash trees have brittle wood, and during storms or high winds, branches can break off, potentially causing damage to property or posing a safety risk. Hiring a tree surgeon for regular pruning can help prevent this.
• Root Damage: Ash tree roots can spread widely and may damage underground pipes, driveways, or other structures, especially if planted too close to buildings.
• Pests and Disease Spread: Diseased Ash trees, particularly those suffering from Ash Dieback, can become unsafe and spread pathogens to other nearby trees. Regular tree health monitoring by an arborist can help catch issues early.

How Tree Surgeons Can Help

Tree surgeons and arborists are skilled professionals who can help homeowners manage and care for Ash trees. Here’s how they can assist:

• Disease Diagnosis: Tree surgeons are trained to identify signs of Ash Dieback and can recommend appropriate treatments or safe removal if necessary.
• Pruning Services: Proper tree pruning by a tree surgeon helps maintain the health and structure of your Ash tree, reducing the risk of falling branches and ensuring the tree remains safe and attractive.
• Tree Removal: If an Ash tree is severely diseased or poses a risk to your property, a tree surgeon can safely remove it. They have the tools and expertise to handle tree removal, even in challenging locations.
• Tree Health Monitoring: Arborists can monitor the health of your trees and can help catch early signs of disease and prevent long-term damage.

The Ash tree is a valuable part of the UK’s natural heritage, but it faces growing challenges due to disease and other environmental factors. By knowing how to identify an Ash tree, care for it, and recognise signs of poor health, you can help preserve this beautiful tree. If you have concerns about the health of your Ash tree, a qualified tree surgeon or arborist can provide expert advice and services to ensure its longevity and safety.

LES Tree Services can help with hedge trimming, stump grinding, tree trimming, tree pruning, tree removal or general tree care. If you’re trees or hedges are becoming a problem, and you need help give your local tree surgeon a call on 01772 885100.