Installing your own irrigation system

By Melanie Mathieson
Gardening Guru

Have you ever wished that you didn’t have to haul the sprinkler around the yard to water your flower beds? If so, I may have a solution for you. If you install a soaker hose system around your garden you can help minimize the work and effort involved come watering time and maximize watering efficiency at the same time. This low-level watering system installed from hoses or pipes laid along the ground, delivers the water very close to the base of the plants and requires only a low-pressure water supply. Watering at dawn is recommended, as night time watering provides ideal conditions for slugs, snails, mildew and moulds. To enhance your system, a timer can be installed between the faucet and hose and the garden can be watered even when no one is home. Soaker hose systems work well for shrub, tree, perennial, annual and vegetable gardens, but they do not work for lawns.
Soaker hoses are available in various lengths. They are black rubbery looking flexible hoses with many small holes that allow water to seep not spray out. Some garden supply centres also sell rigid pipe that works in a similar way. Multiple hoses can be connected together to create lengths of up to 100 feet. It is not recommended to extend beyond 100 feet as after this length the water pressure drops too low to allow the additional length of hose to weep. Some garden stores sell kits and parts to connect pieces of soaker hose together, giving you greater flexibility in your design and water efficiency. You can custom design your system and create multiple watering zones of less than 100 feet total each by using Y-type shutoff valves or hose splitters.
Steps to installing a soaker hose system:

Lay Out the Hose in Your Garden Beds
Position soaker hoses throughout the garden near each plant within 6 to 12 inches of the base. On slopes, run across the slope, not up and down. In perennial beds, keep hoses about 18 inches (sandy soils) to 24 inches (clay soil) apart. For annual plants space the runs closer, 12-18 inches apart, to make sure water reaches their shallow roots. Pin the hose into place with U-pins (created from lengths of aluminum wire or coat hangers) wherever it is needed to secure the hose’s position.

Hide the Hose
After testing the soaker hose to see that it waters the area well, cover it with 2 inches (or more) of mulch, such as wood chips, bark, leaves, compost or even decorative rocks. The mulch keeps water from evaporating and helps spread the water flow. It also helps protect the hose from the sun. Have you ever felt the temperature of water that was just sitting in a hose out in the sun? It’s hot! Make sure you do not bury the end that needs to be connected under the mulch. This installation can become semi-permanent in the shrub, tree and perennial garden. For annual and vegetable gardens you pick the hose up each fall and store until the next season. I leave my system in place all year round.

Watering times
Start out by running your soaker hose for about 40 minutes once a week or 20 minutes twice a week for sandy soils, and annual plants and gardens that have shallower roots. The goal is to wet the soil in the plant’s root zone. You can tell if the plant is getting enough water by digging a hole with a trowel to see if the root zone is wet (wait awhile after watering before you check, so the water has time to soak in). Leaves may droop a little on hot days but if they stay droopy after the hottest part of the day, they’re probably too dry. Drooping can also be a sign of overwatering but again, check the soil first. Once you’ve got the timing figured out establish a routine and stick to it unless there is a lot of rain.

Maintaining Your Soaker Hose System
Once or twice a year, unscrew the end caps and flush out any accumulated sediment. Flushing it at the start of the year will help you check for leaks, and ensure that it’s not plugged. Make sure everyone working in the garden knows the soaker is under the mulch, so they don’t accidentally damage it. Most cuts or nicks can be fixed with connectors and hose clamps, available from garden supply centres that sell soaker hose.

Recommendations:
This is a great system but do not install it until you are satisfied that your perennial (or tree and shrub garden) is at least 90% finished with plant insertion. If you have a garden where you continuously move plants around, the soaker hose will never be in the right place and will have to be constantly repositioned.
Attach quick connect adapters to the ends of all your hoses. It allows for easy identification of your end and a quick hook up to the hose supplying the water.
Do not use sprinkle/spray hoses for this. They must be soaker hoses as the water pressure from the other types is too strong and can blow of your mulch. Check the label carefully before purchasing.
Don’t let water freeze in the hose over winter as they will split. Usually the hoses will drain themselves after the last watering in the fall but if you expect a sudden cold snap that may freeze the hose, you can blow the hoses out with compressed air from a compressor.