How to Irrigate Evergreens
- 1). Determine the water needs for your evergreens and water accordingly during all times of year when the ground is not frozen or covered with snow. For example, arborvitae needs high moisture levels to thrive, while junipers have low moisture needs. Remember to water more frequently during the summer, especially those evergreens that need more moisture. For all evergreens, water deeply in the fall or early winter before the ground freezes to help them through the winter.
- 2). Apply mulch around evergreens and out 2 to 3 feet from the drip line, especially for those plants that require lots of water. A 2-to-3-inch layer of mulch will help the soil conserve water.
- 3). Water evergreens properly. Water them near the canopy drip lines rather than right up against the trunks. Most evergreens have feeder roots under the drip lines and outward a few feet, not next to the trunks. Place a hose near the drip line and let the water trickle out for an hour or so. Move the hose several feet and repeat until you cover the entire drip line.
Source...