How to Deep Water Plants

How to Deep Water Plants. Deep watering is the process of driving water down into the soil so that it merges with the natural moisture level deep underground. It encourages roots to follow the water downward, eventually joining the moisture level where they can help themselves to a drink any time they please.

Here are a variety of ways to do it.

  1. Use a soaker hose around the drip line of existing landscape trees. Turn on the water to a very slow flow and allow it to run as long as overnight. Roots grow where the soil is damp. By driving the water deep into the soil, you encourage roots to follow.

  2. Purchase a deep watering tool that can be attached to the end of a hose. Turn on the water 1/4 strength - any stronger will wash the soil away from the roots. Plunge the spike end into the soil around the drip line of existing landscape shrubs. Move around the tree, watering in 8-10 places around the drip line.

  3. Wrap the end of a hose with an old cotton sock. Use a rubber band to hold it in place. Turn on the water to a slow trickle and place the sock end of the hose near the drip line. Allow the water to run for several hours, then move the hose 1/4 revolution around the drip line. Continue until the entire perimeter of the tree has been watered. The sock breaks the force flow of the water so that it doesn't wash the soil away.

  4. Set up permanent soaker hoses under redwood trees and cover with mulch. Although redwoods are shallow rooted and don't require deep watering, their wide, flat mat of roots will benefit from a biweekly application of water applied directly to the roots during the summer and fall. Allow the water to run for several hours at a very slow volume.

  5. For flowering summer annuals, such as marigolds, form an earthen bowl around the plant and fill it with water, allowing the water to soak into the earth. Do this once a week to encourage deep root growth and larger, stronger plants.

  6. Tip

    The drip line is the imaginary circle on the ground under the tree that corresponds to the outer edge of the leaf canopy. Landscape plants such as trees and shrubs require deep watering in areas that receive no summer rainfall. Deep watering should be done once a month during the dry season unless the landscape trees and shrubs are drought resistant natives such as oaks or redbud. Cover soaker hoses made of recycled rubber tires with mulch to protect them from the sun so that they will last longer.


    Make sure the soil has excellent drainage if you plan to deep water. Soggy, water-logged soil can cause plants to rot or become diseased.