No-flop, no-fungus perennials with this irrigation system.
Using standard sprinklers, it's not easy to maintain a closely planted perennial border that combines both herbaceous flowers and woody shrubs. The heavy, overhead stream of water can cause tall, soft stemmed plants to become top-heavy and collapse. And as plants grow, they often block the sprinklers. When water is applied over foliage, there's more chance that plants will get fungus diseases, especially as plantings become more crowded. And there's no way to give shrubs extra water to encourage deep rooting without overwatering other plants. To overcome these problems on a recently planted perennial and shrub border, landscape designer Michael Bates of Santa Rosa, California, experimented with a combination of low-volume mini-sprays and drip emitters. The mini-sprays, installed on stakes and lengths of 1/4-inch polyethylene tubing, give him flexibility in dealing with unpredictable plant growth. As plants block sprays or die out, he can rearrange the sprays to accommodate the changes. Since the mini-sprays sit only 6 to 8 inches off the ground, their emission doesn't wet much of the foliage. The spray is fine enough that it doesn't knock down softstemmed plants. To supply extra water, Bates placed several 1-gallon-per-hour (gph) emitters around each foundation shrub. These include barberry, butterfly bush, philadelphus, shrub roses, and spiraea. Polyethylene tubing supplies the water To distribute water to all sides of the perennial bed, Bates installed 1/2-inch polyethylene tubing around its perimeter (the tubing runs from pressure regulators, filters, and automatic valves at the water source). He also ran distribution lines across the bed at 6-foot intervals so he could supply water to plants in the center. Bates then installed the mini-sprays on 2to 3-foot lengths of 1/4-inch tubing. He used enough of them to overlap spray patterns (depending on the brand, the spray radius ranges from 4 to 10 feet; some are adjustable). To correct spray patterns, he turned on the system and adjusted placement of the mini-sprays. Although perennial beds are usually considered high water users, once they're established they grow best with deep, infrequent waterings (assuming the soil is amended and drains well). Bates waters according to summer temperatures, for 2 to 3 hours every five to seven days (test soil to determine water penetration). If the current drought becomes even more serious and he has to cut back on water use, Bates can cap off the sprayers and keep valuable shrubs alive with emitters set to run infrequently. El
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|Date:||Jun 1, 1990|
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