And don’t forget the thirstiest part of your property: your lawn. To calculate your lawn watering costs, “you need to determine the total area of your lawn/garden, and figure out how many inches of water your lawn needs,” says McKenzie. It’s usually one inch per week, and it takes about 0.62 gallons of water to equal one inch per square foot of lawn. “Multiply the total area of your lawn by 0.62 to figure out the total number of gallons needed to cover it, then multiply this number by the cost per gallon of water in your area.” For example, if you have a 1,000 square-foot lawn, it would take 620 gallons to provide an inch of water to the space. A simple way to measure that inch is with a small watertight container set out on your lawn. Mark an inch up from the bottom of the container, then run your sprinklers or irrigation system until the water level reaches that mark. Once you figure out how much it costs to water your garden and lawn one time, you can easily estimate how much it costs you to keep your outdoor plants hydrated over an entire season. And while there’s no getting around the fact that all plants need water, there are several tricks and tips for reducing just how much water you need to keep your garden thriving. Here are a variety of simple ways to lower your garden water bill.
Mulch to retain moisture in the soil.
Mulching, whether with wood chips, grass clippings, straw, or a mixture of organic materials, serves many purposes in your garden. Mulch can prevent the sprouting of weeds, which compete for the same nutrients as your plants. And it can protect plant roots from extreme hot or cold temperatures. But mulch also provides a protective layer that prevents soil from drying out too quickly. “Mulch shades the soil to conserve soil moisture,” says Angelo Randaci, Earth’s Ally master gardener and horticulture expert. “It reduces evaporation and protects the soil from drying out from heat and strong winds.”
Add plenty of compost.
Compost is a rich, organic material that provides numerous benefits to the garden, such as enriching the soil with nutrients, which helps reduce the need for chemical fertilizers. Compost also plays an important role in retaining water in the soil as well as preventing soil from hardening into less water-permeable layers (known as soil crusting). “Compost reduces soil crusting, helping water absorption into the soil,” explains Randaci. “The addition of compost also helps water to move more readily through the soil.” You can add compost regardless of the season, but it’s especially helpful in the warmer months. “The high-water holding capacity helps during summer droughts and reduces plant stress,” he adds.
Know when to water.
On busy days, you might forget to water until you notice your plants starting to droop. When, rather than just how often, you water your garden may seem irrelevant—but timing can make a difference. “Watering in the morning is best,” says Randaci. “If watering with an overhead sprinkler or other device, it is best to water in the morning so the leaves have a chance to dry off before evening and prevent fungus and bacterial problems.” Watering in the morning may be complicated, especially during the week on work days, so if the evening is a better option, that’s possible, too. “Watering in the evening is okay, if applying water to the root zone only,’’ says Randaci.
Choose an irrigation system.
Having a reliable irrigation system can be an easy way to ensure your garden receives the water it needs without worrying if you have sufficient time in your schedule to reach for the garden hose. There are different styles and types of watering systems, such as sprinklers or tubes that you place around the plants. “Micro-irrigation includes low-volume water uses of spray, drip, subsurface, and bubbler irrigation,” explains Randaci. By “drip irrigation” he means a process by which small droplets of water are released near the base of the plant. “Drip irrigation is one of the most efficient methods of irrigating your plants [because] water goes directly to the roots and reduces evaporation.” The benefits of micro-irrigation include reducing water consumption, soil erosion, and weed growth, he adds.
Water deeper, but less frequently.
The way you water the garden can also influence how often your plants will need to be watered before they wilt. One method called deep-watering involves slowly watering plants for about 15 minutes, instead of having the hose nozzle on full blast and doing a quick pass. “Deep-watering involves getting water to go a few inches further down than the roots of your plant,” says Randaci. “It encourages root systems to grow deep,” where soil tends to dry out more slowly. Watering your plants in this manner may take some time to figure out, because there are many variables. According to Randaci, “Getting water to the desired depth will be different depending on the plants you are growing, the season, temperature, how much water nature provides, and your type of soil.”
Choose drought-tolerant plants.
It likely comes as no surprise that not all plants need the same amount of water. Familiarizing yourself with which plants grow well in the region where you live can provide plenty of insight on whether your garden will continually be thirsty or can go without for longer periods. “Native plants to your area are always a good choice, because they will have minimal, if any, watering needs,” says Randaci. Another option is to look for specific species that need little water. “Choose ornamental plants that are defined as ’low water use’ or ‘drought-tolerant,’” says Randaci. Knowing how much or how little water each plant needs to thrive can make a huge difference in their growth as well as your water bill. According to Watersense, a partner program of the EPA, the Environmental Protection Agency, native plants don’t need much or any water except from typical rainfall, after their first growing season in your garden. “Most native plants can thrive on occasional rainfalls and may require manual watering only during drought,” says McKenzie.
Harvest rainwater.
Another option to consider is having a rainwater system in place that allows you to collect rainwater from your rooftop and gutters. The rainwater is then stored in a barrel or container to use during times of little to no rainfall. “Harvesting rainwater is a good idea, because it is a free and clean source of water,” says Randaci. Because rain falls directly from the sky without passing through tubes or filtration systems, there is no added chlorine, making it ideal for your plants. Having access to rainwater also reduces your dependence on the city’s water—and there may be additional reductions. “Irrigating with rainwater will offset initial water costs and may qualify for tax incentives,” explains Randaci. McKenzie adds that “the current tax rebate is usually $50 for every 100 gallons of stored rainwater, but such incentives are not available in every state; 20 states encourage rainwater harvesting, 17 don’t restrict it, and 13 states allow harvesting with various restrictions.”
