Why Not Consider Drip Line Irrigation?
On average, vegetable gardens require 1” of rain per week for optimum growth. This translates to 623 gallons of water per 1000 square feet. They may need more in warmer years or in sandy soils, and certain plants demand more water than others. While our growing seasons often deliver sufficient precipitation, the rain may not be spread throughout the season the way our plants demand. Watering with garden hoses daily helps plants get established just after seeding and transplanting, but watering every day with this method may use more water than is necessary. It may deliver so much at a time that it runs off of the garden bed and does not soak into the ground. This can lead to puddling, inadverdent watering of weeds, and water that does not infiltrate into the soil can be lost to evaporation. To ensure that your plants get the water they need without wasting water in the process, consider installing a simple drip irrigation system in your landscape, flower beds, or vegetable gardens.
Drip irrigation delivers water through thin plastic lines that have evenly spaced emitters, or holes where water comes out. Water is delivered slowly and directly to plant roots, reducing water losses to evaporation. Drip lines are available with different emitter spacing and flow rates.
Most drip irrigation lines will indicate how many gallons per hour are delivered from each emitter, and using these numbers you can calculate how long you need to run your drip irrigation to provide the appropriate amount of water. Critical components of a drip system include a filter, backflow stopper, pressure reducer, a main line (sometimes called “headline” or “lay flat”) that carries water from the source to the garden bed, and drip lines that are attached to the main line.
Fittings and adapters specific to the diameter of drip line are required to connect drip lines and main lines. The pressure reducer is needed for running a drip system off of some wells or municipal water. You can use valve fittings to connect drip lines to the main line if you rotate watering beds, or if certain beds demand more water than others. For low-hassle watering, install a timer to regulate how long the system runs and the number of times it turns on in a day or week.
Reduce your water bills even more by collecting water for the garden with a rain barrel. Rain barrels catch water that runs off of impermeable surfaces, such as a roof, and stores them in a tank until use. Many have a valve where water flows out slightly above the base of the barrel to allow some sediments to settle. Drip irrigation can be run off of rain barrels if the rain barrel is elevated so that gravity causes the water to flow. Rain barrel-collected water generally meets safety standards for irrigation water, but it is best to apply it directly to soil and not to the consumable plant part.
Monitor how much rain you receive by placing a rain gauge in the garden. Then, estimate what additional irrigation you will need beyond the weekly total. Watering in the morning is generally best to prevent foliar disease and minimize evaporation. Mulching and increasing soil organic matter are good strategies for conserving water applied to the garden. Drip lines can be placed under mulch. For vegetable beds, use 3” of straw mulch, plastic mulch, or landscape fabric. Choose hardwood mulch or pine straw in landscape beds. Increase soil organic matter by planting cover crops each year and adding compost. By combining good soil organic matter, mulch, drip irrigation and a rain barrel, you will set yourself up for a successful garden season and good water conservation practices.
Please contact the Caldwell Extension Center with other questions on gardening at 828-757-1290 or visit us anytime at https://caldwell.ces.ncsu.edu.