San Diego County – Due to several years of below average rainfall, water users across San Diego County are being asked to reduce their water use by as much as 20 percent or more. The question for tree owners is, knowing that their trees have grown up with and now depend upon landscape water for survival, how they can ensure that those big, beautiful, mature trees don’t suffer.
The importance of mature trees is obvious. From economic values to air quality, from social benefits to energy conservation, trees provide an important resource for everyone. They provide shade and beauty, and are often expensive to remove if they should die. A mature tree that is lost may take decades to replace.
So how much water do trees use?
For mature trees, estimates range from 50 up to a few hundred gallons of water on a summer day. And about 95% of the water absorbed by a plant or tree is transpired through the leaf area.
If a tree is not getting enough water, problems develop quickly. The first is that feeder roots begin to die off. Then the leaves wilts, yellow, shrivel, and drop as the canopy becomes sparse. It is at this point that pests and diseases become opportunistic, secondary concerns. Once the Permanent Wilting Point (PWP) is reached there is no possible recovery. Water is the single most limiting essential resource for tree survival and growth. Without enough of it, a mortality spiral begins which takes a tree from healthy to stress to declining to death in a very short period of time. Here is what you can do for your trees:
- Perform proper pruning: Do not over-thin; be sure there is an objective before pruning;
- Postpone or minimize construction near trees; physical damage and trauma to a tree or its immediate surrounding area can cause stress and decline;
- Apply mulch; a 3-4 inch thick layer of mulch can save 20-30 gallons of water per day per 1000 square feet;
- Provide water; deeply and slowly, within the dripline of the tree, 10 gallons for each diameter inch of tree, approximately once per month in winter (if no rain), twice per month in summer – you may need to reallocate water from other areas of the landscape;
- Do not cut roots; this will reduce a tree’s ability to take up water;
- Avoid soil compaction; roots are easily damaged and lost by even minor compaction
Looking for an Expert opinion on your Trees? Contact Our Certified Registered Consulting Arborist for San Diego.
