Watering Turf: How, When & How Much
Water is essential to all life…… too little water and we die, too much and we drown. The same is true of the grass in our lawns. Water makes up 70% to 80% of the weight of our lawn grasses and the clippings alone are nearly 90% water, Many newly laid lawns are destroyed or damaged by not watering enough or quickly enough.
The first watering of newly installed turf is the most important. Begin watering immediately after the installation of the new turf. The first watering establishes how well the grass will perform in the years to come.
When to Water your New Turf
It is essential to begin watering your new turf within a half hour after it is laid on the soil. Apply at least 1 inch (2.5 cm) of water so that the soil beneath the turf is very wet. Ideally, the soil 3 to 4 inches (7- 10 cm) below the surface will be moist.
Do not water using a hand held hose. It is far better to use a sprinkler. You will get better coverage by using a simple round metal hose-end sprinkler (48 – $ 10 at the hardware shop).
Watering Tip #1:
Pull back a corner of the turf and push a screwdriver or some other sharp tool into the soil. It should push easily and have moisture along the first 3 or 4 in. (7 to 10 cm), or you need to apply more water.
Watering Tip #2:
Make absolutely certain that water is getting to all areas of the new lawn, regardless of the type of sprinkling system you use. Corners and edges are missed by many sprinklers and are particularly vulnerable to drying out faster than the centre portion of the lawn. Also, areas near buildings dry out faster because of reflected heat and may require more water.
Watering Tip #3:
Run off may occur on some soils and sloped areas before the soil is adequately moist. To conserve water and ensure adequate soak-in, turn off the water when run-off begins, wait 30 minutes and restart the watering on the same area, repeating as needed.
For the next two weeks (or until the turf is well rooted), keep the below-turf soil surface moist with daily (or more frequent) watering of approximately one-quarter inch (0.6cm) each. Especially hot, dry or windy periods will necessitate increased watering amounts and frequency.
Watering Tip #4:
As the turf begins to knit it’s new roots into the soil, it will be difficult, impossible and/or harmful to pull back a corner to check beneath the turf (Watering Tip#1), but you can still use the sharp tool to check moisture depth by pushing it through the turf and into the soil.
Watering Tip #5:
Water as early in the morning as possible to take advantage of the daily start of the grass’s normal growing cycle, usually lower wind speeds and considerably less loss of water because of the high temperature evaporation.
Watering Tip #6:
If the temperature approached 100(37 C), or if high winds are constant for more than half of the day, reduce the temperature of the turf surface by lightly sprinkling the area. This does not replace the need for longer, deeper watering, which will become even more critical to continue during adverse weather conditions.
During the remainder of the growing season, most lawns will do very well with a maximum total of one inch of water a week, coming either from rain or applied water. Soil conditions may dictate that the amount be applied in two settings, approximately two to three days apart. This amount of water, properly applied is all that is required for the health of the grass, providing it is applied evenly and saturates the underlying soil to a depth of 4 to 6 in. (10 to 15 cm).
Watering Tip #7:
Infrequent and deep watering is preferred to frequent and shallow watering because the roots will only grow as deeply as their most frequently available water supply. Deeply rooted grass has a larger “soil-water bank” to draw moisture from and this will help the grass survive drought and hot weather that rapidly dries out the upper soil layer.
Proper watering techniques are a critical aspect of lawn watering, equal in importance to the issues of when to water and how much to water. Here are several key factors to proper technique:
Avoid hand sprinkling because it cannot provide the necessary uniformity. Most people do not have the patience, time or “eye” to adequately measure what is being applied across any large areas of lawn. The only possible exception to this guideline would be the need to sprinkle the surface of the grass to cool it, or to provide additional water near buildings or other heat-reflecting surfaces.
Understanding the differences between sprinkler designs because each type has its advantages and disadvantages. Its proper use will be determined by the type of sprinkler you select.
In-Ground systems require professional design and installation and they require routine adjustments and regular maintenance to be most efficient and effective. The greatest mistake made with most in-ground systems is the “set it and forget it” philosophy that fails to account for the changing seasonal water requirements to maximise turf growth or even allowing the system to operate during or following a multi-inch rain storm. Another frequent problem is when heads get out of alignment and apply water to the sidewalk, street or house-siding, rather than to the lawn. The potential for evaporation loss is reduced and trees, shrubs and other plants do not block the pattern (or very noticeable if they do).
Hose-End Sprinklers range in complexity, cost and durability, but are highly portable and can provide uniform and consistent coverage, when properly placed on the yard and adequately maintained. Sprinkler that do not throw the water high into the air are usually more efficient, as are larger drop generators because prevailing winds are less disruptive of distribution patterns, the potential for evaporation loss do not block the pattern (or very noticeable if they do).
Several times during the growing/watering season. Routine maintenance is important to check for blocked outlets, or misaligned sprinkler heads, regardless of the sprinkler design.
Verifying watering uniformity can be accomplished with a very simple and inexpensive method that uses only four to six flat bottomed, straight sided cans (tuna fish, cat food, etc.), a ruler and a watch.
Follow these steps:
Step #1: arrange the cans at random distances away from any sprinkler, but all within the area you assume is being covered;
Step #2: run the sprinkler for a specific amount of time, say half an hour OR run the water till a specific amount of water is in at least one can, say 0.5in. (1.3cm).
Step #3: measure the amount of water in each can, checking uniformity. Some variation is expected, but a difference of 25-30% or more between any two cans must be addressed by replacing or adjusting the sprinkler or relocating the system.
This measuring method should be used across an entire lawn that has an in-ground irrigation system to assure maximum coverage and uniformity.
Watering difficult areas such as slopes and under trees requires some special attention to achieve maximum benefit and a beautiful lawn.
For slopes, see (Watering Tip #3)
For Areas Near and Under Trees you need to know the water requirements for the specific trees, as well as for the grass. Despite having deep “anchor” roots, trees take up moisture and nutrients for the top six inches of soil…the same area as the grass, Trees and grass will compete for water. Watering sufficiently for the grass may over-water some varieties of trees and under water-others. A common solution is not to plant grass under the drip line of the trees, but rather use that area for perennial ground covers, flower beds or mulch beds
How Much Water Is Needed And Applied
The amount of water your lawn requires and receives will determine its overall health, beauty and ability to withstand use and drought. Keep in mind that too much water can ruin a lawn just as fast as too little water.
One inch (2.5cm) a week is a “watering rule of thumb” suggested for most lawns; however, this will vary between different turf species and even among cultivars of a species. There will also be varying water requirements for seasonal changes and still more differences brought about because of different soil types.
Look at your lawn to determine its water needs. Grass in need of water will have a heavy grey-blue cast, rather than a blue-green or green colour. Also, foot prints will completely disappear within a few minutes. Inspecting your lawn frequently will help you detect water requirements and to avoid over- or under-watering.
Verify water quantities with the same measuring can method mentioned above, except you will want to note the TIME it takes to collect a specific amount of water. For example if 0.25in. (0.6cm) collects in 30 minutes, you can easily calculate that it will take one hour to apply 0.5in. (1.3cm) of water and two hours to apply 1 in. (2.5cm) of water.
Water Timers can help provide consistence and even be programmed to turn on and off when no one is awake or at home. Some timers measure just the amount of time water is flowing through the device, while other measure the number of gallons of water flowing through it. Read the timer’s directions to determine how your operates.