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Case Study By Lynette Von Minden Going Deep T rees are the focal point of almost every landscape — residential and commer- cial. Home buyers scan real estate listings to find those with "many tall, mature trees." New home purchasers and commercial property developers often place "tree planting" at the top of their landscaping to-do lists. The benefits of trees run the gamut from their simple aesthetic beauty to their positive effects on the environ- ment. They provide beautiful views, ob- scure not-so-beautiful views, generate cooling shade, create wind breaks and cleanse the air. Economically, trees can lower energy costs and increase property values. Unfortunately, while everyone seems to want trees on their properties, new trees require a great deal of care to be- come well-established. Most trees are purchased from local nurseries and then transplanted onto residential and com- mercial sites, a process that can definitely take a toll on a tree's health and vitality. "In a typical transplant project, as many as 20 percent of trees do not survive be- yond two years," said Rick Foster, senior product manager for Rain Bird Corpo- ration's accessories group. "Over 50 per- cent of newly planted tree mortality is due to water stress, poor drainage or a lack of oxygen in the root zone." Whether planting a smaller potted tree or a large tree that's been recently removed from its comfortable spot on a nursery's growing fields, there's always a chance that it will experience this type of transplant shock. Caused by significant loss of a tree's root system, transplant shock can also make trees far more vulnerable to insects, drought and diseases. Because a newly transplanted tree's root system was severed and reduced when it was dug up for transplanting, the tree often loses more water than its root mass can absorb. Trees suffering from water stress struggle to produce energy, diminishing the tree's overall growth. To a greater or lesser degree, transplant shock lasts until a tree is able to restore the natu- 26 Landscape and Irrigation July/August 2012 Deep root watering systems help trees survive and thrive ral balance between its root system and its top, or crown. Although it's certainly possible to greatly improve a tree's chances of sur- vival with painstaking care, trees planted along street medians and highways or in large numbers on commercial sites are often unable to receive regular one-on- one attention. "In these situations, groundskeepers or city employees are un- able to regularly visit every newly trans- planted tree and give it the water it needs to survive," Foster said. "Particularly in the case of trees transplanted along roadways or in street medians, extreme sun expo- sure and heat reflecting from nearby pave- ment can cause tremendous stress that leads to high levels of tree mortality." Foster said that products like Rain Bird's Root Watering Series (RWS) product can remedy this type of situa- tion. Created to help increase the chances of tree and shrub survival, the RWS consists of various sizes and models of patented basket-weave canisters in- stalled on their own irrigation zone with water-dispensing devices such as bubbler heads and drip emitters. "About 10 or 15 years ago, we observed that contractors were piecing together their own root watering systems out of separate components," said Foster. "While it was great that contractors and landscape architects understood the need for deep root watering, the fact that they were assembling their own systems led to inconsistent per- formance and questionable quality. We designed the RWS to elimi- nate that inconsistency and give professionals a consistent, high-quality option that they can install right out of the box." The size of the RWS canisters and the number of canisters used per tree or shrub depends on the tree or shrub's size. For trees, Foster recommends two to three. For shrubs, one or two canisters are typically sufficient. The canisters are installed near the tree's root ball with the goal of helping the roots get out of the original hole and into the adjacent soil. Because tree roots tend to grow toward water sources, the RWS needs to place water into this tar- geted area. www.landscapeirrigation.com Photos provided by Rain Bird Corporation