The wilting and color changing are a giant beacon or call to action to water these plants. Those that are committed to maintaining these areas will comply and start with supplemental irrigation. Trees, on the other hand, will take much longer before signs of drought stress will become apparent.
So many times, trees are abused. You will see them planted near streets, paved walkways, or in parking lot islands where root growth is impeded. Radiant sunlight and heat make for a very inhospitable place to be. You will find them in the middle of hardscapes or areas of little soil volume, all while little is done to care for them or properly irrigate them.
But trees are an important part of our ecosystem: they provide shade, filter air, sequester carbon, reduce runoff, and create a cooler overall environment.
In the case of drought, there is an accumulative effect. Sometimes, over years, that will eventually lead to death. In less severe cases, they can recover, but when drought stress is considered to be long-term or these conditions reappear year after year, decline will happen.
Sometimes the signs are ignored, but they can be serious. A few of the first things typically seen are leaf scorch and unseasonal leaf drop. This results in lack of vigor. Leaves are transpirational and photosynthetic sites. Reduced transpirational pull puts a serious damper on the plant’s ability to take in moisture or nutrients from the soil. Losing them, the plant becomes less efficient in water movement and carbohydrate production while consuming precious reserves to stay alive.
As the conditions persist, the tree will fail to compartmentalize, leaving open wounds or pruning cuts allowing pathogen and insect entry. In a weakened, stressed state, rootmass becomes diminished, making the tree far more susceptible to insects and diseases that will eventually mean the end. Borers prefer stressed trees, and they can mean certain doom.
Outward signs of stress may only seem mild initially, but when paired with other stressors, could lead to a decline scenario where the aesthetic value is lost. Then the next step is a chainsaw and chipper.
Water availability is the number one factor in tree development; lack thereof will start the clock. If you have never seen it, The Manion Decline Spiral is a great model depicting the numerous inputs to tree loss. In this model, predisposing factors lead to inciting factors ultimately ending with contributing factors. The cycle can be broken though.
Beginning with proper irrigation for trees is vital. Most of the active roots are within the top 12 inches of soil so deep watering, meaning 2 inches of water, is a good starting point. For trees with turf under them, it will take more.
In areas of temperatures ranging from 95 to 105 F, this process should go on every four to six days, remembering to soak the entire area under the canopy. The frequency can be reduced as temperatures drop for established trees, but newly planted or young ones should be watered every two to three days.
The use of plant healthcare materials like EMPRO Kelp Complex, EMPRO Carbon Complex, and Hydretain can greatly improve stress tolerance. Kelp and Carbon-based materials will enhance root development while Hydretain helps reduce drought stress. Another strategy is vertical mulching or rootzone excavation and backfilling with EMPRO Granular Soil Enhancer. This will go a long way to reduce environmental stressors.
Fertilizing trees under stress is not recommended. It can make the situation worse. Other ideas include reducing competition for water and using a good organic mulch under the canopy which will create a friendlier environment to help trees thrive.
Feel free to reach out with questions about tree care especially during severe drought conditions.