Deep root watering a large tree comes down to checking that the topsoil is dry, then applying about 10 gallons per inch of trunk diameter slowly around the dripline so it soaks 12 to 18 inches down. Established trees need this less often than young ones, but each watering still has to go deep.

Why does a large tree need water at the dripline rather than the trunk?

Because its roots spread out to the dripline, the ground beneath the outer edge of the branches, and beyond. Water poured only at the trunk misses much of the root system.

What are the steps for deep watering a large tree?

Four steps, in order:

• A soil check, watering only once the top few inches are dry
• A trunk measurement, planning about 10 gallons per inch of diameter
• Slow application at several points around the dripline
• A deep soak to 12 to 18 inches, with the next watering after the topsoil dries again

Which tools deliver water deep around a large tree?

A soaker hose left running for several hours around the dripline, or deep root tools set 12 to 18 inches into the soil at points around it. Five to six Deep Drip 24" Tree Watering Stakes are driven into the ground around a well established tree and moved outward as its roots grow.

Frequently Asked Questions

Where is the trunk diameter measured?

At about chest height, roughly 4.5 feet above the ground.

How can watering depth be checked?

By pushing a long screwdriver or soil probe into the ground a few hours after watering. It slides in easily through moist soil and stops where the soil turns dry.

Can a large tree be overwatered?

Yes. Soil that stays soggy or pools after rain points to too much water or poor drainage.

What time of day suits deep watering?

Usually early morning, when cooler air means less water is lost to evaporation.