How to Check Soil Moisture

At least once a month for the first summer, check the soil moisture around your new trees using one of the two methods below. This will help you fine-tune your watering system to better fit your soil type and environment. Be sure to check moisture on a day when your sprinkler/drip system doesn’t water.

• Dig Test: Take a shovel and dig down 12 inches, just outside the root ball, and check whether the soil is moist to the touch. If it’s pretty wet on a non-watering day, you’ll need to reduce the amount of water the tree is getting. If it’s dry to the touch, increase the amount of water to maintain sufficient moisture between watering.

• Probe Test: Buy a soil moisture meter at a garden center or farm store and you can easily check soil moisture without any digging. These probes usually have a simple gauge that reads either Dry, Moist, or Wet. If it’s not a watering day, the meter should point to the Moist section. On a watering day, it may read Wet. Most new trees will begin to show signs of stress if much time is spent in the Dry category. The critical range for soil moisture is the entire top two feet of soil. The soil probe test is limited to the length of the probe, so if at all possible, purchase an 18-24” probe, to be sure you’re getting a deep enough moisture reading.