Ryegrass has very low drought tolerance and requires supplemental irrigation when natural rainfall is lacking. Most homeowners can accomplish watering their ryegrass with regular lawn sprinklers and garden hoses. If you have a larger lawn, you may need to move the sprinklers around more to cover the whole lawn, but it is well worth it to keep your ryegrass looking green and healthy. One inch of water per week applied over the entire lawn is usually sufficient to keep your ryegrass lawn healthy.
Set up lawn sprinklers in your yard. Space them so that the sprays overlap some since the spray may alter slightly when the wind blows. This will ensure total and even coverage.
Connect each sprinkler to a garden hose and connect the hoses to your water spigot. If multiple hoses run back to the spigot, you can use a "Y" fitting to connect them.
Turn on the water at the water spigot. Observe the spray pattern from the lawn sprinklers. If the water isn't reaching as far as it should according to the lawn sprinkler, you may need to disconnect a few sprinklers from the system and run them separately. Turn off the sprinklers until you are ready to run them.
Run the sprinklers between 10 p.m. and 6 a.m. This will mimic the natural dew pattern on your lawn, which will lower the chance for lawn disease from having wet grass. Irrigate until you apply 1 to 1 1/2 inches of water over your entire lawn. Use a pan to measure how much water is applied. This will tell you how long you need to run the sprinklers.
Irrigate once each week at the above amount. Irrigate more frequently during periods of heat when your grass shows drought stress. Drought stress symptoms include wilting leaves and grass that doesn't spring back up when walked across.