Three basic conditions must be met for plants to thrive: light, nutrients and water. Of these, water is the trickiest to deliver correctly: Too much at once, and the plant could drown; too little and growth and/or yield will be compromised. A good drip system helps to take the guesswork out of watering, as it controls the amount of fluid that is delivered over a prescribed period of time, and it directs the flow straight to the roots of the plants, where it is needed most.
Setting Up Drip Irrigation
Draw a basic sketch of the garden area. Draw where hose bibs are located, and measure the distance from them to the vegetable plot(s) to be watered. Note which crops are thirstier than others. For instance, peppers will require much more water than sunflowers; write down their placement in the garden and relative water needs for future emitter choices.
To the hose bib, attach a manifold, if desired. Preferably, the water from the single faucet should be accessible from several threaded connectors. To one of the threads, attach a pressure regulator. Next, connect a backflow regulator to prevent water from returning into the piping. Finally, screw on an in-line filter, as even small particles can block the narrow tubing and drip emitters.
Cut a length of 1/2-inch main water line long enough to reach a garden plot. Crimp one end. Push the other end into a 1/2-inch hose bib female connector, and attach it to the in-line filter. Lay the main line out to the plot.
Attach secondary lines to run out to the bases of the plants. Cut a length of 1/4-inch line long enough to run along a row of plants. Use the punch tool to make a hole in the main line. Push one barb of the 1/4-inch in-line connector into the hole, and the other into one end of the secondary line. Make more secondary lines as needed to feed all the plants in the garden bed.
Choose drip emitters according to the needs of the plants in the row. For crops with high water needs, such as melons, use emitters with high flow rate, such as two gallons per hour. For drought-tolerant plants, use emitters that drip as little as half a gallon an hour. Cut the line where it will lie at the base of the stems and insert the in-line emitters. Either crimp the end of the 1/4-inch line or insert an end-line emitter.
Test the system. Make sure everything's connected, and turn on the water. Check for proper dripping and leaks. Repair as necessary.