Top three activities recommended to increase lawn-watering efficiency during summer?
Mow high: Raise the mower to three inches
Water deep: Use only one inch of water per week
Increase soil depth to minimum six inches
MOW HIGH: Raise the mower to three inches
The most common lawn mowers have notches for setting blade height. Set the notches at the highest setting. This will be three inches. Specialty mowers may go as high as six inches. Read your mower instructions. Allowing the green part of the grass to grow longer has the following advantages:
- Less mowing;
Longer grass shades the soil, so less evaporation;
Long grass keeps feeding roots, even after cutting, so plant doesn’t have to race to make more green to feed the roots;
A stressed plant is more prone to disease;
The lawn will hold more moisture;
Longer grass shades weeds, which then will not grow.
WATER DEEP: Use only one inch of water per week
For southern Vancouver Island, grass needs slightly less than one inch (2.5 cm) per week, including rainfall. It is not physically possible for grass to absorb any more than one inch of water per week.
How would I measure that amount?
For automatic sprinkler systems, ask your irrigation specialist or lawn care provider. You can also place a rain gauge or shallow cans (tuna cans work well) in strategic locations and run sprinkler for 15 minutes. If this puts half an inch of water into the can, then you only need to water your lawn for 30 minutes each week. Call 250-203-2316 or e-mail email@example.com for a rain gauge.
What if water starts running out on to the pavement long before an inch is collected?
That means you have very poor water retention due to wrong type of soil or not enough soil. Try a 10-minute “cycle and soak” watering regime to improve water absorption (water for 10 minutes and then let the water soak in for 10 minutes). Amend your soil by leaving grass clippings behind and a quarter inch top-dressing of good soil in spring and fall. Aerate in spring and late summer.
Where does the One inch (2.5 cm) number come from?
To find out exactly how much water a plant needs, it is necessary to understand how much water evaporates from the soil and plant surface and how much is released from the plant itself through transpiration. This water is referred to as the evapotranspiration or ET number. This is the water that needs to be replaced by irrigation.
The ET for grass was calculated at 42 sites using a reference grass crop and an equation recommended by the United Nations Food and Agricultural Organization. For southern Vancouver Island, the ET indicates that grass needs slightly less than one inch per week, including rainfall. It also indicates that it is not physically possible for grass to absorb any more than one inch per week.
INCREASE SOIL DEPTH
The desirable soil depth approaches six inches or more. Measure the depth of your soil and if it’s less than six inches (which is a common occurrence in suburban homes) consider adding a quarter inch of good quality top soil or compost, once or twice per year, in spring and fall.
More tips to keep your lawn green on less water:
Over time, soil becomes compacted. Compacted soil loses its air spaces around the soil particles leaving no room for water (or air). Irrigation or rain water cannot penetrate the soil and will run off onto adjacent areas instead of heading down into the soil, where it can be absorbed by the grass roots. Aerate your lawn at least once a year, preferably in early summer or early autumn, when grass is growing the fastest. This is a critical step to improve irrigation efficiency. You can aerate your lawn using a hand aerating tool or aeration machine available at garden stores and rental facilities.
Mulch is a protective cover of organic material placed on soil to retain moisture, reduce weeds, and provide nutrients to the soil as it breaks down. Mulching mimics leaf cover found in forest floors and attempts to replicate a natural process.
For lawns: Leave grass clippings behind when mowing. Or rake them, compost then and then spread thinly over the lawn.
For garden beds: Add grass clippings, leaves, wood chips, newspaper or cardboard.
Grass grows best at a pH of 6.5 and will be healthy up to pH 7.0. Below pH 6.5, your soil is too acidic for grass and you will need to add lime. You can test your soil, or you can take it for granted that in this area, soil will more than likely be acidic and just lime on an annual basis, in spring or fall. It won't hurt your lawn....or you!
Lime has come a long way from the powdery, dusty stuff that blew all over the place. Dolopril lime is perhaps one of the best limes available today. It's granular for easy application. You can spread it much the same way as fertilizer, following the instructions and precautions on the bag.
CREATE ISLANDS OF SHADE
Some Campbell River gardeners do not add any water to their lawns, yet they stay green much longer than others. Apart from the above lawn care recommendations, one of the main sources of long-lasting, water efficient lawns is the presence of partial shade throughout the day.
To create shade, establish beds within your lawn and plant flowers, shrubs or trees.
- Mow lawn.
- Cover area with cardboard or thick layers of soaked newspapers.
- Add bed border.
- Add six to 12 inches of good soil.
- Choose ornamental or native plants that require little watering once established, or plant fruits or vegetables.
Naturescaping uses native plants in your garden. Advantages abound.
- Native plants are adapted to the Campbell River climate and a wide variety of habitats, from wet to dry and shady to sunny.
- There is no shortage of colours and variety.
- No watering required after plants are established in approximately two years.
- Native plants increase habitat for local pollinators (e.g. red-flowering currant attracts hummingbirds).
- Native plants reduce need for pesticides.
AUTOMATIC SPRINKLER SYSTEMS
Professional installation of an underground irrigation system will cost more up-front, but provides a water-efficient system. Certified irrigation professionals are up to date on the correct techniques and equipment for efficient watering. Do-it-your-selfers should seek professional advice before installing their own system.
Don’t “Set and Forget”
Check and service automatic sprinkler systems every spring and once per month during summer. Summer use, traffic and winter freeze-thaw cycles can affect the performance of your irrigation system. Below are some things to look for:
- Check timer settings, ensuring sprinklers run at the right time.
- Adjust for odd and even numbered months.
- Add a rain sensor.
- Check for blocked or misaligned sprinkler heads and repair.
- Check for leaks and repair.
- Test backflow prevention valves, check valves.
Irrigation installation companies should be able to provide this service.
- Use a hose with automatic shut-off for washing cars, boats, driveways, exterior of homes.
- Wash vehicles on lawn, use a bucket and rag, or use commercial car wash.
- Use a broom instead of a pressure washer to clean a drive-way. Misting the surface first helps control dust.
- Use a hose with shut-off nozzle to lightly spray surfaces for dust control.
- To reduce evaporation, cover your pool when not in use.