Check the soil. To check the soil’s moisture, either use a soil probe or place your finger in the soil. If it is dry and hard, watering is appropriate. If there is some moisture, continue to monitor the soil’s moisture level.
Water weekly. Gardeners should continue to water plants weekly as needed. Prioritize watering needs. Start with newly planted trees or those planted within the last two to three weeks. Large established trees should be watered every two to three weeks in dry periods.
Don’t forget the trees on your parkway. During droughts, they need water too.
Water the roots. There is no reason to water the leaves of a plant. Water the soil, where the roots are. The Morton Arboretum recommends watering within the drip line of a tree, from the trunk out to the end of the branches, to reach the roots most effectively. The water-absorbing roots are within the top 2 feet of soil. The objective is to keep roots moist but not wet.
Avoid frequent light watering. Instead, water deeply at wider intervals such as once a week. Let a hose run slowly at the drip line of the tree, moving it around occasionally. At medium pressure it will take about five minutes to produce 10 gallons of water. If using a sprinkler system, place a straight-sided container under the sprinkler and water until it has filled 1 to 2 inches. If you deliver the equivalent of 1 to 2 inches of rain, the water will percolate into the soil about 6 inches, reaching the fine water-absorbing roots.
Keep checking in fall. Trees and shrubs, especially newly planted ones and evergreens, need ample water in their root systems as they go into winter. Continue to water as long as you can.