May 2020 is the driest May on record since 1896 and the fourth hottest May on record since 1880. So, with hot, dry weather ongoing, this month we will look at what action is needed to maintain a healthy garden.
Watering Newly Planted Trees – How Much, How Often?
‘Water is life’s matter and matrix, mother and medium. There is no life without water.’ – Albert Szent-Gyorgyi, M.D. who discovered Vitamin C
Watering is one of the fundamentals of successful tree (and shrub) establishment. Trees will require watering for the first two years post planting, after which they will generally be able to look after themselves. How much and how often to water a newly planted tree will depend on numerous factors including soil type, location, air temperature, wind speed, size and species of tree.
The following is a good general guide as to how much and how often to water your newly planted tree.
- Use a watering can with a rose attachment to water or a sprinkler or other such method that will administer water slowly and at a low pressure, mimicking rainfall.
- Water should be applied to the surface of the tree planting pit, evenly distributed over the whole area to encourage even root development.
- A newly planted tree should be ‘watered in’ when planted.
- A newly planted tree should be continuously watered from bud burst in spring to leaf fall in autumn (for deciduous trees).
- It is occasionally necessary to water evergreens a little during the winter months if it is particularly dry. This does not need to be done routinely and can be a response to a period of dry weather.
- During the height of summer, water should be applied at a rate of 20 litres (roughly 2 x 5-gallon buckets) every other day. A lesser volume water is generally required during spring and autumn.
Top Tips to Make the Most of your Watering
Make sure that you are able to quantify how much water you are applying to your tree and how often you are applying it. If there is a problem with watering, it is much easier to diagnose if you know how much and how often.
Mulch your tree. Mulch should consist of either sheet material or organic material and be 1.0m in diameter with the tree at the centre. If using organic material, it should be at least 50mm in depth but no more than 100mm in depth. Mulch should only be applied to the root system; tree stems should be mulch free. The mulch should resemble a shallow bowl not a flat plate. The mulch helps to retain water, prevent weed growth, control soil temperature, and gives you an indication of where you need to water!
NB. Newly planted trees still need watering, even after it has been raining! It is the root-ball of the tree that needs watering and often rainfall is intercepted by the canopy and does not reach the planting pit.
Reference: Barcham Trees
Leaf Scorch on Young Deciduous Trees
I have three young but established trees in my garden with leaf scorch. They came into leaf as I would expect but now look rather sorry for themselves.
Scorch is more common in spring but can occur in the autumn as well. Scorch happens whenever water is lost from the leaves more quickly than the roots can take it up. Leaf scorch rarely causes long-term damage, but it can leave an affected tree unsightly for the remainder of the growing season. A wide range of environmental factors can cause or contribute to scorch such as frost, drought (including under-watering), water-logging, drying winds, hot sun and salt-laden winds in coastal areas.
The foliage on affected trees turns brown, particularly around the tips and margins. It is often followed by the leaves curling and shrivelling. In some cases whole leaves can become entirely crispy and there may be some minor die-back of branches.
- Choose a sheltered spot protected from strong winds and midday sunshine.
- Choose the right tree for the soil conditions.
- Plant in moisture-retentive but well-drained soil.
- Don’t feed too early or too late in the season (don’t feed between November and March). Avoid over application of high nitrogen fertilisers.
- Keep newly planted trees well watered but not over-watered.
- Mulch around the base of trees. Make sure the mulch is kept away from the trunk of the plant.
- In very cold, windy weather, a temporary windbreak maybe worthwhile.