As demand for water resources and concern for water conservation increase across the U.S., drip irrigation is becoming a popular method to reduce water bills and safeguard water resources. Implementing drip irrigation in a garden or landscape is also a way to streamline watering your plants. With new irrigation controllers that can be set and operated from your phone, you can water your Illinois garden while sitting on a tropical beach; the convenience factor is a big perk.
What is drip irrigation?
Drip irrigation is a method that enables water to gradually seep onto the soil surface or directly into the root zone through a system of pipes, valves, tubing, and emitters.
There are many reasons gardeners should incorporate drip irrigation into their landscapes and gardens.
- Overhead watering is prone to runoff before water penetrates the soil, especially on clay soils. Drip irrigation is highly efficient. 90 to 95 percent of the water applied infiltrates into the soil, while the opposite is true for overhead watering on hot, windy days.
- Due to their efficiency, drip systems use 30 to 50 percent less water than sprinkler irrigation.
- Applying water directly to the soil minimizes leaf wetness, reducing the risk of plant diseases.
- Drip irrigation provides moisture to desirable plants, while weeds struggle to get the moisture they need.
- Drip irrigation takes the guesswork out of watering. A timer can be set on a spigot to turn the system on and off and apply the exact amount of water needed, leaving you more time to enjoy your garden.
In the past, drip irrigation could be intimidating for homeowners, and early systems had their share of problems, ranging from clogged emitters to uneven distribution of water.
Today, the development of new materials has improved and simplified drip irrigation. There are nearly endless combinations of drip irrigation systems that can be set up for use in landscaping beds or the vegetable garden. Many local garden centers and online retailers sell customizable drip irrigation kits that can easily connect to an outdoor water spigot.
Components of a drip irrigation system
At the start of your drip irrigation system, there are three essential components: a backflow preventer, a filter, and a pressure reducer.
Most drip irrigation kits come with a backflow preventer that stops water from flowing backward into a home’s drinking water system. While many modern outdoor faucets have built-in check valves to prevent backflow, it remains wise to install the included backflow preventer.
Sediment can clog drip emitters. Using a filter helps reduce sediment buildup and is often included with most kits. Filters can be disassembled so the mesh can be removed and cleaned. Depending on the source of your water, the filter can clog with sediment and limescale. Rinse off your filter a few times during the growing season, or more if you have high amounts of calcium or sediment in your water supply.
Drip irrigation systems run on very low water pressure; therefore, every system requires a pressure reducer. The typical water pressure found at the spigot is around 30 psi. If a drip irrigation system is run from a water source without a pressure reducer, emitters can be damaged, and a drip system’s lifespan may be shortened.
After the three components listed above, you transition into the delivery portion of your drip irrigation system. Following the pressure reducer is the mainline. The mainline is often a plastic tubing ranging from 1 inch to 1/4 inch wide (most common for homeowner gardens would be 1/2 inch) that supplies individual beds. When a mainline T's off or transitions into a garden bed, that is called a lateral.
One useful tip is to include manual valves at the start of each lateral. That way if there is repair needed or a particular garden bed needs less water, you can manually turn off that section or zone of the irrigation system.
Laterals supply the emitters that drip near the base of your plants. Drip can be as simple or complex as the gardener desires, and there are many different types of drip irrigation emitters.
- Drip tape appears flat when the system is off, but when filled with water becomes rounded. The emitters are spaced within the tape. Drip tape is often less expensive but doesn't bend, and so is often used in straight row crops and vegetable gardens.
- Single-mounted drip emitters are typically used to irrigate trees, shrubs, containers, and hanging baskets. Emitters are ‘plugged’ into a flexible polyethylene pipe buried under mulch and run to wherever water is required.
- Drip tubing is similar to drip tape, where the emitters are in the tubing, but drip tubing can bend. Drip tubing is typically used in landscape beds and vegetable gardens.
Drip irrigation systems do need to be winterized to reduce damage from freezing water. The backflow preventer, filter, and pressure reducer should be removed before a freeze, dried, and stored inside. Drain out the irrigation system by opening up the lowest part to let gravity move water out of the lines. An air compressor can be used to blow out the system. The primary goal is that any hard plastic fitting left outside needs to be clear of water to prevent cracking.
Good Growing Tip of the Week: For most homeowners, drip irrigation kits are as easy (and fun) as putting together a Lego set. For larger drip irrigation projects, you will need to begin to account for pressure loss and even distribution of water. That's when it is helpful to consult or hire a professional irrigation installer.