Another week of hot, dry weather … another opportunity to visit about watering! So let’s start off with:

Watering the garden. Reducing home water use has become a major concern whether you live in town with high utility bills or in a rural area with water scarcity. Outdoor water use often comprises more than half the water consumed by the average household and is an area where many significant improvements can be made. Careful planning, proper soil preparation, efficient watering and use of mulches combine to make the most of every drop of water for your garden.

Watering efficiently. Two factors influence the general practice of watering: the water available in the soil environment and the rate the plant is using water. The first depends primarily on the soil’s water holding capacity as well as the root mass. The second depends on some special characteristics of plants which allow them to retard water use and, more important, on the weather conditions such as temperature, wind and humidity.

The type of soil you have influences its capacity for holding water. Soil is composed of small particles, the largest particles being classified as sand; medium sized particles as silt and fine particles as clay. Varying amounts of each size particles in any soil determine its texture. Some soils may have different textures at different depths. A layer of clay or hardpan beneath a loamy soil can restrict drainage. The soil texture in many garden areas has been altered by construction activity including the addition of fill soil.

Principles of plant water use. Garden plants use water as part of the photosynthetic process and to move nutrients from the soil to the upper parts of the plant. A continuous flow of water moves from the root system up through the plant where it evaporates into the atmosphere. In hot, dry conditions, the loss of water to the air is greater than in cooler and more humid conditions. In addition, as the size and complexity of the plant increase there is a greater need for water.

In contrast to landscape plants, garden plants need adequate water to encourage rapid, vigorous growth. Crops should never be under prolonged water stress because yield, quality and pest resistance may be sacrificed.

New seedling plants with a shallow, poorly developed root system may require regular, shallow watering, while a mature plant with it’s extensive root system can use water from a larger area of the soil profile.

Garden crops differ in the size and complexity of their root system. Consider the type of root system when determining which water practice would be most efficient.

The development of the root system of garden crops is such that water is absorbed in the UPPER half of the root system. Thus, if the effective rooting depth of tomatoes is 48 inches, we could assume that most of the water is absorbed in the upper 24 inches and an attempt should be made to manage watering practices to keep an adequate supply in this two foot area.

Suggestions for applying water. Some vegetables, such as lettuce and corn have especially sparse, less developed root systems. Other crops, such as pepper and tomato, have fibrous root systems that more effectively remove water from a given area of the soil.

Cool season vegetables (those planted in spring or fall) generally root to a shallower depth than warm season and perennial vegetables. These crops may need watering more often in stressful periods. Because fall and spring are usually characterized by cooler temperatures and more abundant rainfall, watering during these times is of less concern.

In many direct seeded crops, you must be sure that adequate water is available in the root zone to encourage germination of seeds and allow for initial growth and development. Thus, it is often necessary to provide frequent shallow watering during dry seasons until the crop develops beyond the seedling stage. This is especially true of crops planted for fall production.

With transplanted garden crops, providing water at transplanting time is essential to support the plant until it is able to absorb water from the surrounding soil. In general, apply ½ to 1 cup of water with each transplanted vegetable. Water slowly so that it soaks into the area near the plant, or water at the bottom of the transplanting hole.

A garden crop needs water throughout its life cycle to survive and grow. There are several periods, however, when adequate water is critical. During these periods, the plant may respond to a lack of water by changes that are irreversible during the remainder of its life. We’ve all seen these!

Next week we’ll talk about methods of watering. Remember this, though: “Feed the roots, the rest of the plant will take care of itself.”

Today I’m wheelbarrowing gravel to make paths around some raised beds that are new this season at our urban two-lot farm. It’s been a privilege and a pleasure to take this short break to communicate to you fellow gardeners! Till next week!

Steve Haller, of Osage City, a K-State Research and Extension Master Gardener, writes The Garden Patch featuring gardening ideas and tips for gardeners in northeast Kansas. In his words: “I am not a horticulturist. By education I am an economist. By experience, I am a marketing guru from a local to an international scale. Gardening was taught to me by my grandfather and my Mom, and I’ve been doing it since World War II was going on.”

Steve can be contacted at steveh3002@yahoo.com, or leave questions or comments below.