A little water and a little fertilizer. Critical elements to make your garden grow. Except soon you might be able to scratch the water. A nice thought here in the desert.
The city Transportation Department is testing a slow-release water product and studying water harvesting along a West Side right of way to see if the same techniques could be used elsewhere.
"Dry water" is a combination of water and cellulose gum. It is "planted" in the ground with the plant, and as bacteria erode the cellulose gum packaging, water is released to the roots of the plant, said Kraig Wilson, associate product manager for Rain Bird.
The process takes from 30 days to 90 days and provides a little extra help for the plants to get established. It could be helpful to consumers who could use the products to reduce the frequency of their watering or to keep plants moist while out of town, Wilson said.
The test site for Rain Bird Irrigation Supplement, made by a company called DriWater, is along the south side of West El Camino del Cerro, between North Silverbell Road and Interstate 10.
The test includes both native and non-native plants. It will run for two years, which is typically how long it takes for native plants to be established, said Jason McCutcheon of AAA Landscape, the company that put in the plants and dry water containers.
This city project began as a water-harvesting test site, said Gary Wittwer, a city landscape architect. He said when he heard the manufacturers of the irrigation supplement were interested in doing a trial here, he spoke up.
"I've always felt that we should be utilizing the natural vegetation and reducing the cost to city by doing water-harvesting," Wittwer said, in the case of road rights of way, using runoff from the adjacent streets.
"We can do water-harvesting, but to get plants to establish is very difficult with just water- harvesting itself. This product may get us over that period," he said.
McCutcheon said, "The younger the plants are, the more they need regular watering, and water-harvesting just isn't consistent enough. Once they're established they're better able to get by with less regular watering."
The trial includes three parts. One group of plants is getting the older version of Rain Bird's product; one section is using a newer version with trace minerals; and the third section is just testing water-harvesting techniques, Wittwer said. Water trucks are also spraying the site twice a week until the plants take root and the weather is a little cooler.
"Once everything is established and running, we hope it will be able to take up and manage itself," Wittwer said.
The department is also testing several types of plants to determine which work best with water-harvesting, because different landscaping projects need different plants.
This will help the city decide if the product works for Tucson and which plants it works best with.
At the test site, the product looks like green milk cartons sticking out of the ground. After the water is used, the cartons can be replaced. Wilson said some home-improvement stores sell the irrigation supplement, but none in Tucson.
This city project will cost the department $15,000 for the first year, but all of the Rain Bird DriWater products were donated, Wittwer said.
The overall savings for large projects, like city landscaping, lies more in the labor saved from watering than in water usage, said Wilson, the Rain Bird product manager. This project will allow for less-frequent watering, he said.
"It's hard to put a number on water savings on product like this," Wilson said.