Every year at the beginning of the dry season, I like to remind readers of the importance of conserving our water resources.
As Costa Rica grows and develops, water is becoming a dwindling resource; therefore, it’s the gardener’s challenge to develop a home irrigation system that reduces, reuses and recycles water. Here are important tips that can be of help.
First, cut your gardening activities back so you don’t overstretch yourself, or your water supply. Use a few beds with plenty of diversity. Closer spacing between plants will shade the soil below for lower soil temperatures and slow evaporation.
Mulching with grass clippings or dried leaves is one of the best water-conserving tricks a gardener can use. Each year the Pacific slope and Central Valley face four months of dry, hot weather, practically without rainfall. A blazing tropical sun can overheat exposed soils, endangering the biotic life in the topsoil. Earthworms, for example, retreat to the depths of the soil and remain there until the rains return. Plants become dehydrated quickly in these dry conditions, and wilt rapidly without constant heavy irrigation. But with mulching, your soil will stay moist and cool, permitting better root growth and greater worm activity in the bioactive zone.
Use 15 centimeters or more of fresh mulch on your beds and walkways. In a short time, this will compact to a five-to-seven-centimeter protective covering, giving your garden an attractive carpeted effect.Mulch is also a great cover for dormant planting beds. It keeps the ground moist and weed free, while worms stay busy aerating the soil. As the rains return, this mulch can be incorporated into the soil to increase soil fertility.
Water your garden in the late afternoon or evening. This prevents excessive loss of water from evaporation under the hot sun. Watering in the evening helps to condense more dew on the garden during the night. Try to water the soil instead of plant foliage; a greater amount of moisture will then be trapped in the soil under the mulch.Hand-watering with a garden hose equipped with a showerhead is the simplest and most efficient method.
Shade cloth, or Saran, as it’s known commercially, is another valuable addition to your summer garden. This helps tremendously to keep your garden cooler and to lower evaporation rates. A 50% shade mesh is the best for garden vegetables. However, a bamboo frame constructed over the garden and topped with palm fronds can substitute the costlier shade cloth.
Reuse and Recycle
Many homes can be converted so that plumbing from sinks and showers collects gray water. If you are careful to use biodegradable soaps, this water is okay for watering plants around the home.
Rain catchments are another great way to solve dry-season watering problems. Roof gutters can be connected to a cistern or tanks to collect and store rainwater for dry-season gardening. Just be sure your water catchment tanks are well covered to prevent dengue mosquitoes from breeding around the home.
Container planting around the home and porches is another way to reduce the amount of water you use to produce food. And of course, there’s hydroponics, a system of growing vegetables in a liquid substrate that is recycled over and over again. Some of the results that home gardeners have enjoyed using hydroponics are truly amazing, and the practice is quickly gaining popularity with urban gardeners.
You may need to redesign some of your landscaping to help reduce your water consumption.
For example, experts say showy lawns use more water and require more maintenance than any other part of the home landscape. Try to design your home garden and landscaping using a new approach called xeriscaping (TT, Feb. 6, 2004).
The term comes from the Greek word xeros, which means “dry” or landscaping for dry areas. The word was coined in the U.S. city of Denver’s Water Department in the early 1980s and quickly spread to the southwest United States, California and Florida.
A xeriscape design consists of three important zones. The “oasis zone” is located nearest to the house and should contain showy plants and the vegetable garden, which requires frequent irrigation.
The second zone is called the “drought-tolerant zone,” where plants need an occasional watering during dry times. This area may consist of fruit trees and other ornamental plants that are drought resistant.
Next is the “natural zone,” which ideally needs no watering during the dry season. This area is usually away from the home, with little traffic and visibility, and should consist of totally native plants that weather the dry season without water. For example, the hardy local grass for the lawn called jenjibrillo may turn brown during the dry season, but never needs watering and greens up as the rains return.