Five Steps to Protect Your Trees from Drought

In the midst of a multi-year drought, we have received many inquiries about preparing and protecting trees for summer drought stress. Shrubs, perennials, and groundcovers are relatively inexpensive to replace. However, replacing old trees that have died is a long process that carries high costs. Depending on age of the tree that is lost; it may take new trees 25 years or longer to grow to size. You have to factor in the cost of tree removal and stump grinding in addition to the cost of the new plant material. 
 
There are many ways to protect valuable shade and specimen trees during a drought.
 
1. If the tree is growing in turf, remove the existing lawn and install a thick layer of mulch to reduce water loss. Turfgrass competes with the tree for moisture. Grass is able to use the irrigation water before it reaches the tree roots. Turf requires regular nitrogen fertilization to encourage lush growth. Trees grown in lawns push out excessive foliage growth. The extra foliage increases the rate of transpiration and water use. Removing the lawn will positively affect the tree.
2. Mulch beyond the drip line of the tree. Tree canopies divert rainwater to the feeder roots at the drip line of the tree. Roots in this area are responsible for the majority of the water uptake of the tree.
3. Deep water your trees to a depth of 1 foot. With drip irrigation, this is an easy task to achieve. If using overhead spray irrigation; eliminate runoff and utilize multiple cycles to ensure irrigation water percolates deep into the soil profile.
4. Soil injections provide moisture directly to the root-zone of the tree. This method of deep watering is especially helpful on drought stressed or declining trees.
5. Prune the canopy of the tree to reduce excess foliage, weak branches, and diseased plant material. Dead and dying limbs should be removed. These limbs may harbor insect borers or canker disease fungi that can contribute to further dieback and decline. If tree crowns are very dense, light thinning will help reduce demands for water and nutrients. But avoid significant over pruning of live branches, as it will add additional stress from defoliation and wounding.
 
A healthy tree is more resistant to drought stress. Proactively monitoring the tree for symptoms of stress from pests and diseases is the best method of Integrated Pest Management (IPM). Pests and diseases can wreak-havoc on drought-stressed trees.
 
Mature trees are one of the most valuable elements of any landscape. Improper care or neglect can permanently ruin the long-term health of a tree. The best advice is to contact a certified arborist and schedule a consultation. To schedule an appointment with our Tree Sculpture arborist, call us today at 510-562-4000.