You’re the envy of your neighbors with your thick, beautiful lawn, right? Well, if you’re like me, the grass really IS greener on the other side of the fence. But, I’ve learned to deal with my lawn envy and instead know that the choices I make are having a better long-term affect on my lawn and on the water bodies down stream from where I live. Here are some summer lawn tips you may not have known.
HOW IS MY LAWN CONNECTED TO WATER QUALITY?
Land use decisions almost always impact water quality. In the case of lawn care, fertilizers often send nutrients into nearby water bodies during periods of high rain and flooding. When fertilizer has been recently applied or over-applied, fertilizer is carried away from the grass and either sent to wastewater treatment plants or directly to nearby surface waters.
Purdue’s Department of Agronomy found 87% of studied Indiana lawns had “adequate” or “high” levels of phosphorus. Most Indiana soil has enough phosphorus to sustain plant life; it will only need phosphorus when new plants are taking root. Excess phosphorus will not be absorbed by soil and plants. Phosphorus in particular can be dangerous to Indiana’s waterways because it contributes to potentially toxic blue-green algae blooms.
HOW SHOULD I FERTILIZE MY LAWN?
Unless you are establishing a NEW lawn or a soil test shows a phosphorus deficiency, use a phosphorus-free lawn fertilizer. If you do find that your lawn needs phosphorus, only use fertilizers with phosphorus in the fall; this is the time of year when plants need phosphorus for root growth. Continue using phosphorus-free lawn fertilizers in the spring.
Homeowners often over-apply fertilizers to try to get a greener lawn faster; the extra fertilizer will not help the grass, but it will very likely hurt nearby rivers and lakes. In general, a lawn will need about one pound of nitrogen for every 1,000 square feet. The type of soil, existing nutrients in the soil, and the quality of the fertilizer can all impact the specific needs of the soil, but this ball-park figure will be about right for most lawns. Find out the right rate for your lawn, and make sure that you only apply that much fertilizer.
The other side of over-application is applying fertilizers too often. Lawns only need fertilized twice a year. The first time should be in the spring, usually early May. Never spread fertilizer if rain is forecast within 24 hours. The fertilizer will at least partially wash away, hurting water quality and wasting money. Fertilize again in late fall, usually sometime in late September or early October.
HOW SHOULD I WATER MY LAWN?
During periods of drought, grass will go dormant but not die, so avoid watering in the middle of a drought. Unless it is severe, grass will almost always survive. In fact, allowing lawns to start to go during short-term dry spells will actually increase rooting. Decide before summer hits whether to water lawns consistently or let them go dormant as conditions turn hot and dry. Do not rotate back and forth. Breaking the lawns dormancy actually drains large amounts of food reserves from the plant.
Water in the morning or evening, and water deeper rather than often. Instead of watering every day, water only once a week and make sure the water is penetrating to the depth of the roots, usually at least 6 inches. When in doubt, dig a small hole in the lawn and check the root depth. In addition to saving water, this trick will stunt the growth of shallow-rooting plants, such as weeds and crabgrass.
Putting down a layer of mulch around trees and plants will prevent evaporation as well. The best mulches to use will be made from bark, peat moss, or even gravel and rocks. Mulching can save as much as 1500 gallons of water a month.
HOW CAN I DO MORE TO PROTECT WATER QUALITY?
Instead of using the hose, try out a rain barrel or two. Rain barrels serve a two-fold purpose: they capture excess rainwater that would otherwise flood the lawn and wash pollutants into sewers and waterways, and they provide a water resource during drought months for watering lawns. Decorative rain barrels are now available, so they can be easily incorporated into an attractive landscape. However, rain barrels should not be used for drinking water or to water a vegetable or herb garden – pollutants from the roof can contaminate the food.
Switch to native plants, and consider a rain garden. Native plants will use water resources more effectively than exotic plants, and will likely require less attention and fertilization as well. Site the plants in places where water will tend to run off and gather speed – i.e. the slope of a lawn. Installing a rain garden will help absorb run-off water even as it adds curb appeal.In places where water pools, attracting mosquitoes and other pests, consider using aquatic plants, or bioswales, to absorb the extra water.