Earlier this week after a heavy afternoon shower I came home from work to see my neighbor’s sprinkler system on. Since they have a built in system it is set to a timer, and comes on daily around 5 pm. Aside from seeing their sprinklers wasting water an hour after it rained, there were many other things wrong with this picture.
Manicured, green lawns are as much part of the American Dream as the homes they surround. We are very invested in our lawns, be it with expensive trimming equipment, fertilizers and pesticides, high summer water bills, or contracted lawn care specialists. Beautiful lawns are all well and good, but consider some of the environmental impacts that are associated with this.
During the summer in New Jersey, and really most of the United States, we see lots of hot dry days, and few showers to naturally keep our lawns green. Regardless of the heat or amount of sunlight, lawns typically only need 1 inch of water per week. If you don’t already have a way measure the amount of rain you get, you can easily set up a cup or jar somewhere to measure. Likewise you can set up cups around areas that you water, and time how long it takes to provide an inch of water, this way you aren’t over watering your lawn and wasting money and water.
While the 1 inch rule is a good one to follow, it also important to water at the correct times. As I mentioned my neighbor waters their lawn in the late afternoon hours, this is not the ideal time to water. Timing when you water is really common sense thing. Think about what happens when you drop an ice cube on the ground in the summer; if it’s the middle of the day and in direct sunlight the cube will melt and evaporate very quickly, but if you drop that cube early in the morning or late at night when its cooler and the sunlight is not direct, it will take much longer to evaporate. The same holds true for lawns. While you might think it is good to water the lawn during the middle of the day while it is getting beat down with excessive sun and heat this is not the way to go.
The ideal time to water is early in the morning between 4 AM and 8 AM. Less water will evaporate during this time, so you’ll get more absorbed into the soil and waste less. While at night you also have the advantage of losing less to evaporation, you could actually be overwatering your lawn if you do so at night, which can allow lawn diseases to spread due to excess moisture.
Not only is it important to water during the right time of day, but the frequency of watering is also very important. There is no need to water your lawn every day. The grass roots will actually become stronger if they receive one good watering per week. So if you get an inch of rain one day, you can go a week without needing to water. This is where knowing how much you are watering is important. If you measure your sprinklers’ output, and know it takes 30 minutes to get an inch of water, you only need to water your lawn for 30 minutes a week if there has been little or no rain.
It is also important to maintain the health of the lawn constantly. If during prolonged periods without rain you allow the lawn to begin to dry up (and thus good into dormancy) before you start to water it will require more water to green up again, and also will break up the dormancy cycle of the grass, causing it to go through large amounts of stored energy, damaging its natural cycle.
Other ways to reduce the amount of water needed include mowing to a length of about 2 ½ inches to allow for less loss in evaporation. Also using sprinklers that apply low large drops versus high fine drops will help reduce evaporation losses further. If you have an automatic sprinkler system, install moisture sensors so the sprinklers will not turn on during or shortly after rainfall.
Rain barrels are another great way to reduce the amount of water used for irrigation. With rain barrels you can store up the excessive water that goes through your gutters during a storm and use it several days later to water gardens. While rain barrels can capture excess rain on impervious surfaces during storms, properly location of the sprinkler to prevent watering driveways and pavement is also a way to save.
These tips will keep the lawn healthy, save you money, and prevent the waste of drinking water. While we aren’t in a drought in New Jersey right now, Texas is in the midst of one of the worst droughts on record, and its spreading to neighboring states as well. Wasting water to keep lawns green, especially when you are overwatering, seems pretty silly when people, animals, ecosystems, and crops are having trouble getting the water they need right in our own country.
Aside from using better watering habits, there are other things to consider when maintaining your lawn. Using fertilizers and pesticides on your lawn can help make it stronger, and more resistant to drought conditions, but these chemicals can also be lost due to water runoff. Timing the application of chemicals is very important; for one thing if they are lost in water runoff they are not absorbed into the soil, so you’ve wasted them. Also once they are lost in runoff they will go into the environment and can cause all sorts of damage. So to avoid losing the pesticides and fertilizers through runoff they should not be applied if heavy rain is expected. Likewise only a very light watering should be done after application to allow the chemicals to soak into the soil.
Planting native species in your property is another method that will reduce the amount of water needed. It is also helpful to group plants with specific watering needs together, as to not waste water on a low demand plant that happens to be next to one with high water demand.
Nobody enjoys seeing high water bills in the summer months. Using water for your lawn wisely doesn’t just save you money, it incredibly important for the planet. About 75% of our planet is covered in water, but only about 1% of that is drinkable. And we are not going to get additional drinking water, what we have now is all there is and will be. On average watering your lawn for an hour uses about 220 gallons of water. Remember that when you see someone’s sprinklers on during or after it rains. All of those gallons of water could be put to better use on crops, for livestock, or our own consumption.