By Joe Julian, Colorado State University Cooperative Extension agent, horticulture and entomology
With the concern about water shortages, water use and rate increases, how does a water-guzzling home garden fit into the picture?
Very easily. Growing vegetables and conserving water are more compatible than most of us might think.
Your vegetable garden can lose water in three ways -- through evaporation, transpiration and percolation.
When summer rainfall is insufficient, water thoroughly to moisten the top 6 inches of soil. You can use the common methods of watering, sprinklers, soaker hoses or hand watering, but trickle irrigation probably is the best. Trickle irrigation involves the use of plastic pipe and a series of small-diameter tubes leading directly to the plants. At low pressure, you can apply a reduced, but sufficient, volume of water.
Mulches also help conserve soil moisture. You can lay down mulch and plant vegetables through it, or you can place mulch between rows after the garden is planted. The mulch also helps control weeds that compete with vegetables for valuable moisture. Mulching materials includes leaves, grass clippings, peat moss, sawdust, ground corncobs, straw hay and shavings. The mulch should be about 3 inches deep.
Sheets of black plastic also can help conserve water, warm the soil and hasten crop maturity. Place the plastic and cover the edges with soil to hold in place. Cut holes at the desired spacing and place seed or transplants in the soil. Water plants through the holds. Because the plastic does not break down, remove in the fall.
You can determine when to water by taking a soil core sample from the plant root zone. Squeeze the sample into a ball. If it holds together in the palm of your hand, the soil is sufficiently moist. If, however, it crumbles, apply water. A foot of dry soil holds 1 inch of water. To determine when an inch of water has been applied, place three or four tuna fish cans under the sprinkler system. Check the time it takes to accumulate an inch of water in the cans; set the sprinkler or other watering devices accordingly. During hot and windy weather, a garden will consume up to 1 and 1/2 inches of water. Water consumption is reduced as fall approaches.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010