The recent record heat combined with very little rain is creating stress on landscape plants. July brought us the hottest day ever recorded in our area in the midst of the driest July on record. Here are some helpful summer time tips for providing adequate irrigation for your landscape beds.

In hot dry weather the plants that are the most important ones to water are any that have been recently installed as well as container plants. However, most established trees and shrubs don’t need to be irrigated. Tree roots can grow many feet deep, tapping into subsoil moisture. Look at the native plants in the forest. Who’s setting out a sprinkler for them?

In the case of recently installed trees, watering them for the first few years is critical, especially during times of hot, dry weather. Tree watering bags slowly deliver water directly to a tree’s root system over an extended time period. The bag is refilled every week or two and the attached drip emitter allows for deep water saturation with no run-off or evaporation. Deep watering keeps moisture concentrations far below the surface, reducing transplant shock, and attracting roots downward deep into the soil. Tree watering bags are available at nurseries and garden centers.

Deep roots will tolerate dry spells better than plants with shallow roots. Water to the root zone then wait until the soil is again nearly dry before irrigating.

Always water early in the morning or in the evening when the temperature is cooler; this method will conserve water because less water will be lost to evaporation and more will soak into the ground. Watering in the heat of the day adds the danger of leaf scorch.

Make sure the water only goes on the plants that need it. Irrigation is made easier, and the plants healthier, if you group compatible plants together. The same amount of water can then be applied to meet the needs of the entire planting bed. Or, in the case of drought-tolerant plants, very little additional water is applied and sometimes none at all. When the rains return this fall, make it a goal to revamp planting beds into companionable water use zones. In the Covington Water District’s WaterWise Demonstration Garden there are some areas that have received no irrigation at all during our very dry July, and the plants are still going strong. Other areas have had minimal watering.

Eliminate water waste, don’t allow the sprinkler to wastefully spray the sidewalk, street or driveway. Water should never run down the street. Leave that for the kids chasing the ice cream truck.

If the soil is too dry to absorb water without run-off, practice cycle and soak irrigation. Turn on the sprinkler for a few minutes, and then turn it off. Allow the water to soak in. Resume watering in intervals to eliminate runoff. Mulch also helps water soak in, while water often just runs off bare soil.

During hot, dry periods, mulching really proves its worth. The soil stays cooler and evaporation of water from the soil is greatly reduced. If mulch has not already been applied before dry weather hits, then be sure to irrigate well before adding a top dressing of mulch.

Soaker hoses placed under a good cover of mulch will supply your plants with water right at the root zone. Soaker hoses eliminate water waste from overspray, runoff and evaporation. With no water sprayed on the leaves, diseases are kept in check. Follow the helpful instructions at www.savingwater.org/docs/SuccesswithSoakerHoses.pdf.

Drip irrigation is another excellent method to keep plants hydrated right at the root zone. Add an automatic timer and you’ll have a worry-free way to water effectively. Often a 60 percent or more savings in water usage may be achieved using such a system.

It may seem like it’s not possible to overwater when the weather is very hot. Unfortunately, homeowners can end up killing their plants with good intentions. Along with water, plants need oxygen in the soil in order to grow. Watering too much causes plant roots to suffocate and die. It can be very confusing because plants show their water-logged stress with signs that are very similar to under-watering: wilting, yellowing and dying foliage, along with leaf drop. The best detective method is to actually check the soil moisture conditions. Simply use a garden trowel to dig down 3 to 4 inches and check for moisture around the plant. If the soil is dry – time to water, if moist – no need to water. Always use the trowel to check soil moisture and not your eyes when trying to decide whether to water or not.

Worried about a high water bill from all the landscape watering? Here’s an easy way to determine how much water you’re using to irrigate. Open your water meter box and write down the numbers that appear under the words “cubic feet.” Apply the typical amount of water to your landscape as you usually do, without any inside use. Go back to your meter and read the numbers again. Then subtract the first number from the second number. This will tell you how many 100 cubic foot units of water have been used. Multiply your number by 748 and discover how many gallons of water have been used to irrigate. If you want to know how much that amount of water costs, visit your water supplier’s Web site. Customers of Covington Water District can visit CovingtonWater.com to compute the cost of their water use.

Hopefully a forecast for showers soon will pan out. Our plants will welcome whatever rainfall nature delivers. Just remember to check the depth of soil moisture before adding additional irrigation water.

Katie Swickard is a Water Resources Specialist at Covington Water District, a WSU Master Gardener and serves on the Board of the Lake Wilderness Arboretum. She also serves in the leadership of the Pacific Northwest Section of the American Water Works Association Conservation Committee. For more information, including lawn watering tips, visit CovingtonWater.com.