Watering

WATERING NEW PLANTS

When transplanted, most plants have a majority of their roots removed. It takes approximately 10 days for the fine white roots to re-establish to meet the plant’s water and nutrient needs. After 10 days some of these roots will elongate up to 24″.

What does this mean?

• The soil around the plant should be moist (wet but not soaked as the plant needs air as much or more than water) up to a depth of 12″ for the first ten days.
• After ten days the goal should be to encourage deeper root exploration. This is accomplished by deep, but less frequent watering. Plants should be monitored for water stress and then watered to a soil depth of 18″ to 24″
• After your plants are well established, provide 1″ of water per week. A rain measurer will let you know how much rain has fallen. You can supplement from that point.

Many of the plants that seem to die in the drought of the summer months, actually succumb to the heavy rains in spring due to the loss of their root system from the rain.

Simple watering instructions

• Water once a day for the first week enough to wet 8 to 10 inches
• Water every other day in the second week same depth as # 1
• After the second week water as needed by checking soil moisture (see below)
• Avoid over watering!!!

Soil-Water-Air relationships

Establishing the correct water-air relationship in the soil is essential for all plants. Oxygen in the soil is necessary for plant growth. Watering too often or too much is likely to exclude the necessary oxygen from the soil. Without enough oxygen, plant roots suffocate and die. Plant parts above ground exhibit symptoms of stress: wilting, yellowing, drying foliage, leaf drop and twig dieback may all occur. (Notice these symptoms are the same for plants getting too little water). Most plants die because of over watering!

Too little water, on the other hand, does not allow the roots to replace water lost by plant transpiration. The roots may dry up and die, while the top growth begins to show abnormal symptoms similar to plants that are over watered. In both cases, either too much or too little water, the plant suffers from lack of moisture in its tissues.

Heavy clay soils are more likely to be over watered than lighter soils. Most soils found in the Chicago area are heavy clay soils. Conversely, light sandy soils are drought susceptible and tend not to be watered enough. Light soil allows deeper and quicker water penetration, but dries out more rapidly as it holds less water. Heavy soils, on the other hand, are slower to allow penetration but dry out much more slowly.

A good rule-of-thumb to follow when watering plants is to fill the entire root zone with water, and then allow the soil to dry out partially before the next irrigation. The amount of drying depends on the plant species and size. Large trees and shrubs can be allowed to dry several inches down in the soil before re-watering. A small or newly established plant will need watering before very much soil drying takes place.

It is essential that gardeners become familiar with how long it takes the root zones of their plants to become completely moistened, and how long it takes the soil to dry before the plants begin to show stress and need re-watering. It is also necessary to understand that quick, light sprinkling does not do the job of wetting the entire root zone.

Handy Tips to check for Soil Moisture

• Check the soil before you water because over-watering can be more detrimental than under-watering.
• A Ross Root Feeder, or other metal probe, is a great tool to check soil moisture. Push the probe into the soil applying the pressure of your body weight. If the probe goes in too easily the soil is too wet. If the probe is hard to push in then the soil is too dry. If the probe goes in slowly and evenly then the soil moisture level is probably about right. After a few tries you’ll learn what the “feel” should be like when the soil moisture is just right.
• Alternatively, dig a small hole 3 or 4 inches deep and feel the soil. If the soil feels moist to your touch then you don’t need to water. If there is visible water or water quickly seeps into the hole, defer watering for a few days. Although we think of watering during the late spring through the summer, fall watering is crucial to winter survival of newly planted plants. Therefore, continue monitoring watering until freezing temperatures occur regularly.