Irrigating a raised garden bed doesn't have to be complicated, and you don't need to spend hours watering your raised bed with a garden hose. Several irrigation systems exist, but when it comes to raised beds, the simpler the better. Drip irrigation is an effective method that conserves water and ensures even distribution of moisture to garden plants. One drip irrigation technique that works well for raised garden beds is the soaker hose or "leaky pipe" system. You'll find that this irrigation system is inexpensive and easy to install in your raised beds.
Purchase a soaker hose with holes perforated along the length of it. Be sure to get end caps that fit the soaker hose and a quick-connect clamp that will fit both the soaker hose and your garden hose.
Lay the soaker hose in between the rows of plants in your raised garden bed. Start along one side of the raised bed and snake the hose up and down the furrows, doubling back when you reach the end of a row and running the hose up the next row. When you make a turn with the hose at one end of the raised bed, make sure the hose touches the raised bed frame.
Secure the hose at each turn at the end of the rows by hammering in two nails in a crisscross fashion into the raised bed frame and over the soaker hose. This will help to hold the hose in place.
Cut off the excess soaker hose when you've laid all of it in the raised bed and secure an end cap onto the end of the hose. Fasten a quick-connect clamp onto the other end of the hose, which you will use to connect the soaker hose to your garden hose when you're ready to water the raised garden bed.
Cover the soaker hose partially with straw mulch. You can also spread the straw mulch around the base of your plants to help them retain moisture.
Connect the garden hose to the soaker hose using the quick-connect clamp. Run the water at low pressure through the soaker hose for about 15 minutes or until the soil is watered thoroughly. When you're finished watering, remove the quick-connect clamp and place an end cap on the end of the soaker hose.