1. General Watering Timeline: If you haven't received precipitation in winter, it's crucial to water your plants. With dry weather, once a month winter watering is suggested. If the dry weather continues, you may need to go to twice-monthly watering. Write a reminder on your calendar to water. Keep an eye on the skies.
2. Water Above Freezing: Water only when the air temperature is above freezing. You'll want to apply water early in the day so that it will have time to soak in before nighttime freezing. Avoid ice damage - if water stands around the base of a tree, it can freeze and damage the bark. Heavy coatings of ice on turfgrasses can cause suffocation or result in matting of the grass.
3. Don't Forget Your Lawn: Lawn grasses are prone to winter damage, especially newly planted sod and seeded lawns. To help protect plant roots, do not mow your lawn shorter than 4" before winter. Pay particular attention to turf on southern exposures.
4. Watering Evergreens: As a rule of thumb, evergreen trees need more water than deciduous ones. Any plant with shallow root systems, such as pine, spruce, non-native juniper, Euonymous, and Oregon grape will be more susceptible to winter damage.
5. Watering Woody Plants: When watering woody plants that have been planted in the last two seasons, the most important area to water is the distance from halfway between the plant and the outer stretch of the branches to approximately one foot beyond the "drip line" of branch extremities. This also prevents water from building up near the trunk of the plant.