Dry air, low precipitation and inconsistent temperatures can damage trees, shrubs, lawns and perennials if they do not receive supplemental water during the winter months. We often think once trees and shrubs go dormant they don’t need anything. However, beneath the ground, there is still activity going on. Roots continue to grow and need adequate water to survive.
Long periods of little or no precipitation during the fall and winter can lead to injury or death to parts of a plant’s root systems. Damaged plants may appear perfectly healthy and resume growth, but may be weakened and die in the late spring or summer when temperatures rise. Injured plants are also more susceptible to insect and disease problems.
If you are going to water during the winter months, make sure the water and soil temperatures are above 40 degrees and mid-day to allow enough time for it to soak in before freezing temperatures at night.
As a general rule, apply 10 gallons of water for each diameter inch of the tree. Newly planted shrubs require more water than established shrubs, approximately 5 gallons twice a month. However, all shrubs benefit from winter watering in dry winters. Small, established shrubs (less than 3 feet tall) should receive 5 gallons per month. Larger, established shrubs (more than 6 feet tall) should receive 18 gallons per month.
Mulch can help prevent moisture loss and insulate roots. Leaves, finely chopped bark and wood break down and create nutrient-rich compost that will keep soil evenly moist while providing essential nutrients.
Winter is the perfect time to give your trees and shrubs a healthy start to their growing season in the spring and winter watering is the key.