Drought stress is common with newly planted trees and shrubs. Even in a cool, wet summer, the rain rarely replenishes soil moisture stores fully. The soil may be dry around the roots even when the surface appears moist.
Dry, windy conditions are especially likely to lead to water shortages. With experience, it is possible to detect the dull, lifeless foliage indicative of drought stress but by then the tree has already been damaged. Ideally anticipate water loss, and irrigate to prevent damage.
Watering aids can assist watering of newly planted trees such as irrigation tubes (biodegradable tree irrigation pipe made from potato starch is available) or watering bags such as Treegator®.
Overwatering is possible, especially on poor draining soils and with automatic irrigation systems, which leads to rotting roots and symptoms similar to drought. If in doubt dig down with a trowel to the side of the rootball to see if the soil is beginning to dry before watering. The quantity required will vary with soil type but typically 30-50 litres per square metre (4-6 watering cans) each week in dry weather during the growing season will be necessary.
Weeding and mulching
Weeds, lawns and other vegetation intercept water before it reaches the roots of newly planted trees and shrubs.
- Keep a vegetation-free circle at least 1.2m (4ft) in diameter around the plant for its first three years to help avoid this problem
- The circle can be kept weed free through hoeing, using a mulching mat or use of contact or systemic weedkillers
- Laying mulch over this circle is also helpful, although take care to leave a collar of 10cm (4in) around the woody stems that is free of mulch, to prevent the risk of rotting the bark
Fertilisers do not need to be added at planting time but can be used a season after planting if the soil is very poor or a boost to growth is required. However, if you are using a mycorrhizal fungi (e.g. Rootgrow) do not to apply a fertiliser at all as phosphorus (found in general fertilisers and superphosphate) can suppress the fungus.
Corrective pruning on misshapen trees is best carried out while the tree is still young. This may involve shortening or removing any competing leaders and removing damaged, dead or diseased wood. Lower laterals (i.e. sideshoots coming off the main trunk) may also need removing in stages over the first few years if a clear trunk is desirable. See our page on formative pruning of new trees.
Adjusting ties and removing stakes
Inspect tree ties in spring and autumn and adjust ties to prevent constriction of the stem. After two growing seasons the tree should make sufficient root growth to anchor the tree and the stake can be removed.