Drought, lasting months or even years, will have a long-term affect on the health and survival of the trees and shrubs on your property. Given the labour-intensive maintenance of severely stressed trees and potential expense of large-scale replacement costs, the best option is a preventative approach that keeps trees healthier and better able to withstand lack of moisture.
The first step is irrigation. Watering grass is automated on many properties, so it's easy to forget trees and shrubs that have special irrigation needs. Landscape plants should be watered thoroughly and deeply to a minimum of 30 centimetres. Drip irrigation or soaker hoses work well, but remember to keep water off the trunk of the tree.
Mulching is also important as it conserves soil moisture and improves the overall condition of the soil. With that in mind, maintaining adequate soil fertility also helps prevent nutrient stress and minimize the effects of drought.
At all times, but particularly during drought, trees should be cleaned to remove dead, damaged, or dying branches. Trees should also be monitored for insect and disease problems since moisture-stressed trees are highly susceptible to borers, bark beetles, root rot, and stem and canker disease.
Proper care for trees and shrubs before, during and after droughts is critical especially when you consider that moisture stress adversely impacts virtually every plant process including:
- Reduced food (photosynthates) production
- Reduced growth
- Fine root mortality
- Reduced nutrient absorption
Keeping trees and shrubs healthy and planting drought-resistant species whenever possible can help mitigate the loss of valuable landscape investments.