by Stuart Spaulding,
CLIA Certified Landscape Irrigation Auditor Training & Communications Manager at DIG Corp.
Like many products in the current commercial drip irrigation market place, low-volume micro-sprinklers were first developed for use in the agricultural industry, where wholesale growers, nurseries, and tree farmers have utilized them with much success for many years. Recently their use in the landscape field has accelerated, and for two primary reasons: these efficient emission devices share both the water saving benefits of drip irrigation systems, and the reliability, durability, and ease of maintenance of conventional sprinkler systems.
Although there are several landscape situations where they should not be utilized, (irrigating turf areas for example), for some parts of the landscape, low volume micro sprays of one type or another are the ideal choice. They should definitely be considered for use in any planters or flower beds where there are many low profile plants close together, (i.e. annuals) or small areas of groundcover, since it would not be practical to install a single drip emitter near each plant, and using soaker tubing could create maintenance problems.
Micro-sprinklers are also an excellent emission device to utilize on sloped terrain, where traditional high flow sprinklers my cause the water to run-off before it has been able to penetrate down deep enough into the root zone.
To efficiently irrigate plants and trees in containers of any size, perhaps there is no better method than to use micro-sprays, misters, or so-called “spitters”. It is not uncommon for containers to be filled with fast draining potting soils, and if single point source drippers are used, the water may tend to not spread far out laterally below the soil surface. Over time, a vertical path may form below the dripper, eventually boring a vertical tunnel down through the soil, before quickly draining out the bottom. Several different types of container sprayers are now available which connect to either ¼” or 1/8” distribution tubing, and most include a stake that holds the sprayer 4-8” above the top of the soil. The water is then more evenly distributed over the entire soil surface, creating a more uniform wetted area below for the roots to grow.