Water Less, and Keep the Green
Hydrologists and meteorologists are predicting another year with less water than we need. This is leaving homeowners wondering what they can do to make it through the summer without making the already bad situation worse. The good news is there are some simple things you can do in your yard that will make all the difference!
Calibrate your watering system
In short, spend a little time understanding how much water your current system is putting out. Experts in turf science talk about inches of water per week, while typical homeowners measure their water in time, for example, 15 minutes per station every other day. The trouble with measuring water with time is that every sprinkler system is different. The size of the nozzles, the amount of overlap, the time of day you water and even evaporation rates will all affect how much water your grass is actually getting. We suggest performing a water audit. A water audit is where you place 3-5 water gauges in the lawn and run the system for 15 minutes. These gauges look like little measuring cups and will tell you how many inches of water you are putting down in that area in a given amount of time. Water audit kits make calibrating much easier and are available for purchase in the valley for less than $20.
Build your lawn’s drought muscle
When grass is thirsty it will look wilted and slightly bluish in color, not brown. There are some advantages to drought stressing your lawn on purpose especially early in the season. When grass is slightly drought stressed, the plants are encouraged to send roots down deeper in the soil in search of water. Think of this process as building your lawn’s drought muscle. Southwest Idaho’s clay soil does a masterful job of holding water down deep and deeper roots enable the grass to take advantage. The opposite is also true. Putting down less water and watering more frequently encourages roots to stay at the surface making your lawn “water addicted”. The key is to start building the drought muscle at the very beginning of the season. I suggest leaving your sprinkler system off entirely and manually turn it on for a good drink. Then wait to water again until the grass looks wilted, continue this pattern clear until early May. If your lawn will only allow a little water to penetrate before it begins to run off, investigate penetrating agents that will help the soil absorb more water.
Follow the turf expert’s recommendations for water
The rule of thumb is one inch per week in as few watering days as possible until about Memorial Day. As temperatures rise more water will likely be needed but watch for the wilt and aim for extending the watering times and less frequently. In a typical hot July, lawns need closer to 2” per week. Keep in mind that these recommendations are guidelines not hard and fast rules but they are true most of the time.
Encourage life in the soil, not just green grass
Thinking of your soil as a living organism will pay dividends during a drought year. Healthy soils contain billions of organisms, many of which are made mostly of water. They act as a “water battery” in the soil by storing water that plants can use later if they need it. To promote this micro ecosystem, think of your soil like a compost pile. In order to have a healthy working compost pile we focus on “browns (carbon) and greens (nitrogen)”. The same is true in our soils. A carbon to nitrogen ratio of 12:1 to 20:1 in the soil stimulates the good bacteria that hold water. In Idaho soils, we don’t have a lot of available carbon. As a result, over-applying nitrogen to the lawn can throw off our C/N ratio. We suggest using lawn products that are formulated for our area that take into account this lack of natural carbon. Also make a point of top-dressing your lawn yearly with quality compost or a good humate product. These are loaded with carbon and keep the water-holding ecosystem happy.
How you mow will make a big difference
Set your mower deck one notch from its highest setting. Longer grass blades will help shade the ground reducing evaporation. Also sharpen your mower blade two times during the season, once at the start of the season and again mid-way through the summer. A sharp blade makes a clean cut helping the grass heal faster and minimizing the water loss from the cut. This is important in any year but especially during a drought. ACT NOW and cruise into the dry fall with no worries.
It may be that plentiful irrigation water will not be available this season. In a typical water year, the irrigation is available until October. However, some experts are predicting water may not last until September 1st this year. In that case many lawns around the Treasure Valley will suffer. Taking all these factors into consideration it is important to prepare your grass in advance for a water shortage. Mow properly, build the lawn’s drought muscle and encourage your soil’s “water battery” and the grass will be greener on your side of the fence!