Disease and Environmental Stress

British trees are afflicted by a number of harmful diseases. Most diseases are the result of Fungal infection, which we cover in our fungi page. However there are a number of bacterial infections, disorders and environmental conditions that affect trees that are referred to as diseases.

Here are a few of the more common ones.

Dehydration
This simply means the tree isn't getting enough water. It may be due to lack of shade, falling water-table, drought, damage to the roots, salt poisoning, excessive damage to the trunk of the tree or wind exposure.

Flood Stress
Flooding is very stressful for trees in general. Trees can be slow to show symptoms and it can be difficult to judge the effects on the tree. Typical symptoms include:

• Wilting
• Leaf Scorch
• Small leaf size
• Excessive Watersprouts
• Crown dieback

Flood stressed trees are best treated by applying a low-nitrate fertilizer, and mulching the soil about the roots. Flood water often washes nutrients out of the soil and these require replacement. Since flooding can cause defoliation it can be tricky to decide whether leafless limbs are dead. Dead limbs must be removed for the health of the tree so we recommend contacting us if you are unsure about the condition of your tree.

Frost Cracks
Less common than they once were, these are a response to bitter cold dry winters especially in Ash and Maple trees. They are long, usually vertical cracks that open in cold winters, but usually close again in warm weather. If this takes place repeatedly the tree may develop a "frost rib" a deep vertical callus ridge. Frost cracks can lead to heart rot and structural failure within the trunk.

Leaf Scorch
Leaf scorch is a name given to the symptom of leaves browning and/or falling outside of autumn. Whilst a number of bacterial and fungal infections can cause the symptom it is often associated with dehydration.

Shoot (or bud) death
Late spring frosts can kill buds and shoots. This problem is exacerbated by poor tree husbandry such as over irrigation in late autumn or excessive fertilization in late summer as both can cause winter growth.

Watersprouts and suckers
Not really a disease but often symptoms of a stressed tree these are straight vertical limbs off side branches (in the case of watersprouts) or roots (suckers). They are usually only weakly atatched, and rarely fruitful, but are rapidly growing and can become problematical if left too long. We recommend early pruning of watersprouts and suckers.

If you have any questions or concerns about a tree growing on your property please do not hesitate to contact us via email, telephone, fax or post. We will be happy to examine the tree in question and assess any risks to it and your property.