Water Conservation In Your Backyard
Wise use of water for garden and lawn waterings not only helps protect the environment, but saves money and provides for optimum growing conditions. Simple ways of reducing the amount of water used for irrigation include growing xeriphytic species (plants that are adapted to dry conditions), mulching, adding water retaining organic matter to the soil, and installing windbreaks and fences to slow winds and reduce evapotranspiration.
Watering in the early morning before the sun is intense helps reduce the water lost from evaporation. Installing rain gutters and collecting water from downspouts also helps reduce water use.
Plant Needs for Water
Water is a critical component of photosynthesis, the process by which plants manufacture their own food from carbon dioxide and water in the presence of light. Water is one of the many factors that can limit plant growth. Other important factors include nutrients, temperature, and amount and duration light.
Plants take in carbon dioxide through their stomata--microscopic openings on the undersides of leaves. Water is also lost through the stomata in the process called transpiration. Transpiration, along with evaporation from the soil surface, accounts for the moisture lost from the soil.
When there is a lack of water in the plant tissue, the stomata close to try to limit water loss. Wilting occurs when the tissues lose too much water. Plants adapted to dry conditions have developed numerous mechanisms for reducing water loss, including narrow leaves, hairy leaves, and thick fleshy stems and leaves. Pines, hemlocks, and junipers are also well adapted to survive extended periods of dry conditions which they encounter each winter when the frozen soil prevents the uptake of water. Cacti, with leaves reduced to spines and having thick stems, are the best example of plants well adapted to extremely dry environments.
Choosing Plants for Low Water Use*
You are not limited to cacti, succulents, or narrow leafed evergreens when selecting plants adapted to low moisture requirements. Many plants growing in humid environments are well adapted to low levels of soil moisture. Numerous plants found growing in coastal or mountainous regions have developed mechanisms for dealing with extremely sandy, excessively well-drained soils, or rocky cold soils in which moisture is limited to months at a time. Following is a list of low water use plants from various parts of the country:
*Always check with your local State extension service when selecting plants to avoid the potential of selecting a plant that is considered invasive in your particular location.
Efficient Watering Methods
Trickle irrigation and drip irrigation systems help reduce water use and meet the needs of plants. With these methods, very small amounts of water are supplied to the base of the plants. Since the water is applied directly to the soil, rather than onto the plant, evaporation from leaf surfaces is reduced. The water is also placed where it will do the most good, rather than sprayed over the entire garden.
Installing Irrigation Systems
An irrigation system can be easy to install. Numerous products are readily available for home use. The simplest system consists of a soaker hose that is laid out around the plants and connected to an outdoor spigot. No installation is required and the hose can be moved as needed to water the entire garden. A slightly more sophisticated system is a slotted pipe system.
Slotted pipe system installation
Drip or Trickle Irrigation
The basic elements of a drip or trickle system consist of the head, the tubing, and the emitters.
The head is the part of the system that connects to your water supply. The major components of this may include a pressure regulator, a filter, an anti-siphon valve, and an automatic timer. While this may sound complicated and expensive, it is not. Installation of these components will create a better operating system.
Consideration for the Head
Plastic tubing is used to get the water from the source to the garden. This comes in many sizes. A variety of fittings are available to go around corners and to connect pieces.
Plastic Tubing Considerations
Emitters deliver the small amounts of water to the plants. Depending on the design, emitters can either be attached directly to the pipe or attached to "spaghetti tube," a very small flexible tube that can be placed next to plants or in pots. Emitters can let water drip out very slowly, or small sprinkler emitters can be installed to provide a spray pattern similar to a lawn sprinkler. Sprinkler emitters may be appropriate for watering groundcover and lawns.
The size of the emitter will influence the amount of water delivered. Drippers vary in the amount of water delivered per hour. Some deliver as little as one half gallon of water per hour while others deliver up to 10 gallons per hour. Some emitters are adjustable to deliver different rates of water. Sprinkler emitters also are available in various flow rates as well as with different spray patterns and coverage areas.
While these systems need more planning, they are neither expensive or difficult to install. In most cases, no special tools or skills are needed. Plastic pipe is punched with an inexpensive tube punch that assures the proper hole size. Emitters or spaghetti tubes snap into the hole. No gluing or soldering is required. Because the holes are small, they can easily be plugged if you put one in the wrong place. Some systems come with pre-assembled emitters at regular intervals. Drip systems require periodic maintenance. You will also need to check emitters to make sure they are working properly as they can become clogged.
Once you have thought about your watering needs, discuss your ideas with a supplier. Most trickle irrigation suppliers will help you design a system to best meet your gardening needs.
On the Farm
Trickle irrigation systems are frequently used by farmers dealing in high value crops such as vegetables, and small fruits such as grapes and berries, where lack of moisture can mean the difference between a profitable harvest or costly failure. These systems are similar to those used by the home gardener.
High-efficiency irrigation systems for row crops use less energy to pump water and, since they spray water downward, less water evaporates before it reaches the crop.
Farmers implement other water management practices to reduce the amount of water used to produce a crop.
More About Backyard Conservation
The Natural Resources Conservation Service, National Association of Conservation Districts, and Wildlife Habitat Council encourage you to sign up in the "Backyard Conservation" program. To participate, use some of the conservation practices in your backyard that are showcased in this series of tip sheets -- tree planting, wildlife habitat, backyard pond, backyard wetland, composting, mulching, nutrient management, terracing, water conservation, and pest management. Then, simply fill in the Backyard Conservation customer response card, send a Backyard e-mail request to mailto:firstname.lastname@example.org, or call 1-888-LANDCARE.