When the sun starts to shine and the air loses its chill, it is easy to get the itch to wake up a yard in hopes of having the best looking lawn in the neighborhood. Knowing when and how to fertilize a lawn in the spring can be tricky. Over-fertilizing a lawn, or fertilizing it too soon, can cause more problems down the road. Whether you are establishing a new lawn or caring for grass that has seen better days, be sure to know the what, when, and how much when it comes to lawn care.
Do I need to fertilize my yard?
Soil tests are the most accurate way to determine if your yard needs fertilizer. Most yards in the midwest do not need fertilizer to grow. In fact, if applied too early, fertilizer can stunt root growth which will hurt grass growth later in the summer when we reach the drier months. In early spring, it is best to let roots establish first, then focus on grass growth. Without deep roots, grass becomes more susceptible to heat and drought, pests, and disease. Removing dead grass and leaves allows moisture to reach the roots which aids root growth.
Fertilizer can assist grass in maintaining its health when applied at the right time. Late April through May is the ideal time to apply a slow release fertilizer, with the safest date being mid-May when the threat of frost has passed.
Which type of fertilizer do I need?
Established lawns need nitrogen and potassium for growth. Lawn fertilizer will generally come in a 4-0-2 or 3-0-2 formulation. The first number represents the percentage of nitrogen in the bag, the second number is the percentage of phosphorus and the third number is the percentage of potassium. Phosphorus should only be used on new lawns to help establish root growth. Established lawns have enough phosphorus in the soil and do not need additional phosphorus applied. Additional phosphorus will contribute to run-off which negatively affects the environment. In fact, the states listed below restrict or ban the application of phosphorus-containing fertilizers unless it will be used on a new lawn or a soil test proves a deficiency.
States restricting or banning phosphorus-containing fertilizer application on lawns: Minnesota, Wisconsin, Michigan, Illinois, New York, New Jersey, Vermont, Virginia, Maryland, Maine, and Washington.
Nitrogen is the most important nutrient for grass growth as it provides the energy for growth and helps grass maintain its bright green color. It also helps to recover from environmental stress and keep the lawn thick and lush. Yellow grass, thin growth, or grass that isn’t growing is often a sign of low nitrogen.
Potassium is key for water management in grass and also helps to prevent disease. Potassium is often available in adequate amounts in the soil naturally so a soil test will guide you in what you need.
How much fertilizer do I need?
The amount of fertilizer your yard needs directly correlates to the size of your yard. The saying “too much of a good thing is a bad thing” rings true when it comes to fertilizer. Over fertilizing not only wastes money, product, and contributes to pollution, it can quickly kill the grass you have worked so hard to establish. An overabundance of nitrogen will burn your grass leaving you with a brown and dried lawn that will take time to recover.
Before you can apply fertilizer in the correct amount you need to know the square footage of your yard. Measuring with a tape or laser is the most accurate, however Google maps can be helpful as well. Using Google maps on a desktop, find your address, go to “map tools,” then “measure.” Click points around your yard until you close the shape and Google will tell you the total area in square feet. While still an approximate number, this is much better than guessing.
It is generally recommended that nitrogen be applied at a rate of one pound per 1,000 square feet for full sun lawns and about a half pound per 1,000 square feet for shade lawns. To easily calculate your needs, visit the Purdue Turf Fertilizer Calculator.
Following these tips will help you get that golf course looking yard you desired, but think “rough” more than “green.” Mowing your yard too short, less than three inches, opens it up to water loss, pests, disease, etc. Resist the urge to mow every time you see growth in order to maintain your “best yard in the neighborhood” designation.
