Establishment problems
Leaves turning brown and desiccated on young trees and shrubs in the first summer after planting, often remaining firmly attached, indicate that plants have not established satisfactorily. The reason why is often difficult to determine. It may be due to the poor quality and condition of the plants purchased, poor planting or lack of attention after planting.
Always buy healthy-looking, good quality plants with a good root system. Make sure they are suited to the soil and situation in your garden. Always prepare the site thoroughly and ensure roots are well-spread out when planting. Plant in autumn so the roots can establish in cool conditions before the next summer. For the first two years after planting water in dry periods.
Drought
The leaves of even well-established trees and shrubs may turn brown and desiccated from the tips in periods of drought. Prolonged summer drought can lead to premature leaf drop.
Where practical maintain a 5-7.5cm (2-3in) mulch of bark or leaf-litter around all shrubs and younger trees, particularly on lighter, drier soils. For further information see Mulching or Water-wise Gardening
Frost
Late spring frosts can seriously damage shrubs coming into growth (e.g. Pieris; beech (hedges). Leaf margins turn dry and brown and shoots may be killed. Plants will recover but re-growth may be slow.
Wind
Cold, drying winds in spring can cause browning and desiccation of young foliage of Japanese maples.
How to avoid: Ensure they are kept well mulched and are never dry at the roots. For further information see Mulching or Water-wise Gardening
Pesticides
Brown, dead areas on foliage can be caused by using pesticide sprays at the wrong strengths or in hot, sunny conditions; also by misjudged application of some weedkillers. Weedkiller damage
Pests and diseases
Various pests and diseases can also cause browning of leaves
and these possibilities cannot be ruled out. The following
is a list of the most common pests and diseases:
- Fireblight
- Blossom wilt, twig blight and spur canker
- Cherry leaf scorch
- Honey fungus
- Canker diseases
- Phytophthora
- Cypress aphid on conifer hedges
- Horse chestnut leaf-mining moth
- Stem girdling by rabbits, deer, voles and squirrels