Spring Lawn Care

Spring is finally here and a little work now will help maximize your yard for appearance and performance throughout the summer. April is a great time to fertilize your yard to help it green up, and prevent summer annual weeds with an application of a preemergent herbicide.

A slow release fertilizer is the best option for many homeowners. A fertilizer label will include what type of fertilizer is in the bag, slow release fertilizers include sulfur-coated urea, methylene urea, IBDU, and natural organic fertilizers. Try to apply 0.75 lbs. of nitrogen per 1,000 square feet in April. Fertilizer analysis is listed on the bag as three numbers, such as 19-2-20. This analysis means that 19% of that bag is nitrogen, 2% is P2O5, and 20% of that bag is K2O. To figure out how much fertilizer you will need, you need to divide the rate of nitrogen per 1,000 square feet you want to apply by the amount of nitrogen analysis on the fertilizer bag. In the example above, we would divide 0.75/0.19 to get how much actual fertilizer is needed. In this case you would need 3.9 lbs. of 19-2-20 fertilizer to apply 0.75 lbs. of nitrogen per 1,000 sq. ft.

A soil test can help provide answers to other nutritional yards of your turfgrass. An early spring soil test can give you an idea of what your yard will need. Many soils in Iowa do not need additional phosphorous applications, an exception to this is at seeding when phosphorus is needed in higher levels.

One of the most problematic weeds in yards is crabgrass. If you had crabgrass last year, it has already dropped seed for this year. The best way to control crabgrass is with an application of a preemergent herbicide, the key is to apply the preemergent herbicide before crabgrass germinates. Crabgrass will germinate once soil temperatures are above 55 degrees F for at least three days and nights. Typically this happens around mid-April, but that can vary with weather. In a yard, crabgrass will normally germinate near sidewalks first.

With warmer temperatures, also comes the need to mow the yard. Setting your mower at 2.5 to 3 inches height of cut is optimum for most turfgrasses in Iowa. You never want to remove more than 1/3 of the leaf material in one mowing. This means when the grass reaches 4 inches you should mow it back to 3 inches. Typically you will need to mow once a week in the spring to avoid violating removing more than 1/3 of the leaf tissue. Additionally, clippings that are one to one and a half inches long will fall back into the turf canopy and don’t need to be bagged. These clippings have nutrients in them, and help feed the yard. If mowing leaves piles of clippings in the yard, try to spread them out so they don’t smoother the turfgrass. Also make sure the mower blade is sharp when you start the growing season. Most lawn mowers only need a blade sharpened once or twice a year. A dull blade will tear the turfgrass, this creates the potential for diseases and a higher water use rate. Finally, make sure the mower has a clean air filter to make sure the mower can run at peak operating ability.

After application of any fertilizer make sure to sweep the fertilizer off of the hard surfaces to ensure minimal runoff. The same care should be taken after mowing the yard. Make sure to sweep clippings off of the hard surfaces. These clippings contain nutrients, and should be kept out of storm sewers. Grass clippings also can be a traction hazard for motorcycles and should be removed from roads to prevent this hazard.

If you have broadleaf weeds like dandelions that you want to eliminate in the spring you will want to mow the yard twice first. This will help remove dead tissue, and ensure the plants are actively growing and will take up the herbicide. The best time to control broadleaf weeds is in the fall, spot spraying can be done in the spring for weeds that you missed in the fall. If you decide to use a weed and feed type product, make sure the foliage is wet so that the herbicide can stick to the plants and be taken up by the plant. Liquid products should be applied to dry foliage.

Adding additional water is also an important step to consider in the spring. Turfgrass needs about one inch of water a week to continue active growth. Often in the spring you don’t need to add any additional water. If you have an irrigation system, make sure you have rain controls that will keep the system off when it has rained. A good way to see if the yard need water is to walk on the yard and see if you leave footprints in the turfgrass. If the turfgrass stands right back up, it does not need any additional water, but if you leave footprints that is a sign that the turfgrass needs water. A little water stress on the turfgrass will actually force the roots deeper into the soil and help during drier times during the growing season. If you do need to add water, you will want to water deep and infrequently. Try to add all the water in one or two days and then wait for a week until adding more water. This will continue to support the turfgrass while forcing the roots deeper into the soil.

Try to avoid seeding a yard in the spring if at all possible. Spring turfgrass seeding tends to result in more weed competition, prolonged periods of open soil while waiting for soil temperatures to rise, and summer stress on young seedlings. If you have to seed in the spring make sure to avoid using any preemergence herbicides, which will prevent the turfgrass from germinating as well. A September turfgrass seeding will be much more successful than a spring seeding.

Working hard on your yard in the spring will help you enjoy a green yard well into the summer and fall.


Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on April 13, 2018. The information contained within may not be the most current and accurate depending on when it is accessed.