It’s no secret that turfgrass needs water to survive. We all do! Although applying water to grass seems simple, here are five of the most common myths about how, when and where to apply water to turf.
Myth #1 - If it’s brown, it must need more water.
We often equate brown turf and brown plants to dry conditions and a lack of water in the soil, but that is not always the case. Before breaking out the hose, it is important to check the soil to see if adequate moisture is present.
Sometimes brown spots can occur despite adequate soil moisture because of insects or fungal diseases. In these cases, adding more water could make the situation worse. It’s good to always check the soil before adding more water.
Myth #2 - Watering during the day will burn the grass.
Some people mistakenly believe that drops of water remaining on turfgrass leaves on a hot day will act like a prism to intensify the rays of sunlight and scorch the plant. While this is an entertaining thought, nothing could be further from the truth.
It is important to recognize that water conducts heat. Any water that remains on turfgrass leaves will evaporate, and in the process, draw heat out of the plant much like sweat evaporating from a person’s skin.
However, while this is true for turfgrass leaves, too much water in the soil on a hot summer day can heat up the rootzone and damage the roots, a condition known as “wet wilt.” Keep in mind that watering on a hot summer day is fine – just don’t overdo it.
Myth #3 - If I have an automatic irrigation system, there should never be a need for hand watering.
An efficient irrigation system is an indispensable tool to irrigate turf and plants when there is a lack of natural rainfall. But just because you have a state-of-the-art system doesn’t mean you won’t need to occasionally hand water a few dry spots.
Differences due to soil type, compaction, topography, sun and shade patterns will make it necessary to add a little more water to some areas to avoid over-saturating other areas. For example, a sprinkler with a 60 ft. radius covers 11,300 sq. ft. It doesn’t make sense to turn on that sprinkler to address a 10 sq. ft. dry spot. Occasional spot watering ends up being a prudent water conservation practice.
Myth #4 - Ultra-pure water is best for turf.
Although it sounds strange, water that is too pure and devoid of minerals can actually be detrimental to turf and landscape plants. Water that has a salinity level of < 0.3 dS/m is slow to infiltrate and can end up stripping calcium and magnesium from the soil.
When this happens, you can see water sitting on the surface of the turf or running off the surface. Water with some salinity (0.3 to 0.5 dS/m) infiltrates into the soil more readily and does not harm plants.
Myth #5 - Turfgrass is a huge water waster.
Like all plants, different turfgrass species vary in the amount of water needed for healthy growth and survival. Water demand is typically measured as a percentage of the water that evaporates from the soil surface and transpires through the plant, also known as evapotranspiration (ET).
Cool season grasses such as tall fescue and perennial ryegrass typically use 80% of ET while warm season grasses such as bermudagrass and zoysiagrass typically use 60% to 70% of ET.
Many turfgrass species can also survive extended periods of drought and then spring back to life when water is supplied. When it comes to water waste, it’s not so much the plant as it is the person holding the hose or programming the irrigation system who is to blame.