Spring lawn care tips for shoreline homeowners
Healthy lawns can help slow and filter surface runoff; it is also important to understand turf maintenance can affect water quality, especially fertilizer and pesticide applications.
Lawns next to lakes, ponds, rivers or other surface water bodies should be regarded as sensitive areas. Here are some helpful tips to get your lawn into shape while keeping lake health in mind.
Raking away dead grass and rolling lawns
Upon first sight in the spring, many lawns look less than perfect. Lawns may have damage from snow mold, pets, or pesky critters like voles and moles. Due to the relatively mild winter, there hasn’t been too much snow mold observed this spring. This isn’t surprising considering the relatively little amount of snow many areas of Michigan received this winter. However, there’s still the normal matting of turf in areas where snow was piled. Dog owners, whose best friends tend to ‘frequent’ the same lawn area all winter long, are also dealing with localized pet urine damage. To facilitate quicker regrowth, lightly rake the turf with a leaf rake. Raking will remove some of the dead, blighted leaf blades and help the turfgrass recover quicker as temperatures warm. Focus on the areas with the most damage rather than raking the entire lawn.
Be careful rolling lawns in the early spring as soils may still be very wet following snow melt or rainfall. Rolling saturated soils can result in soil compaction and increased runoff. Rolling is popular this time of year to flatten out mole hills and tunnels as well as the lumps and bumps from frost heaving during the winter. It’s better to wait until the soil dries then to roll early and risk making a problem worse by compacting the soil or creating ruts from lawn tractor tires, or even the roller itself.
Applying crabgrass preemergence and fertilizer
A preventative crabgrass and fertilizer combination product is one of the most common applications made to lawns and is usually the first application in the spring. Crabgrass is a summer annual that requires proper soil temperature and moisture to germinate and establish. Eighty percent of germination will occur when the 0- to 2-inch depth soil temperature is consistently reaching 60-70 degrees Fahrenheit. A healthy, dense lawn is the best way to reduce any weed invasion including crabgrass. You certainly do not have to apply a crabgrass preemergence herbicide. People have different tolerance thresholds for weeds in their lawn. Some don’t want to see any crabgrass while others are okay with some crabgrass in their lawn.
If you need to apply preemergence herbicide, be sure to follow best practices for the timing of application to get optimal results and limit impacts to surface water. Soil temperatures can be measured to determine proper preemergence application timing, but a great tool for predicting when to apply preemergence herbicides for crabgrass control is to use growing degree days (GDD). GDD is a measure of heat accumulation used to estimate the growth and development of plants, insects, and schedule applications such as crabgrass preemergence herbicide. Michigan State University has a GDD model available at GDDTracker.msu.edu that uses GDD to recommend preemergence application timing.
Many spring fertilizer applications are made in combination with crabgrass preemergence herbicides. If you are not going to apply a crabgrass preemergence herbicide and are only going to apply a fertilizer, wait until the turf has fully greened-up and grown enough that mowing is necessary. Soils can be slow to warm in the spring and until turfgrass is actively growing it will not be taking up nutrients. Choose lawn-type fertilizers with no phosphorus unless you have a soil test that indicates the soil is low in phosphorus. Avoid applying triple products (e.g., 12-12-12) as applying this amount of phosphorus to a mature turfgrass is unnecessary and is restricted by the Michigan Fertilizer Law (1994 PA 451, Part 85, Fertilizers) unless you have a soil test that indicates need. Fertilizers that contain slow-release fertilizer are also preferred as they release nutrients slowly and eliminate rapid growth following application. Keep your distance from surface water when applying fertilizers. Under the Michigan Fertilizer Act, fertilizer may not be applied to turf less than 15 from any surface water unless: 1) a continuous natural vegetative buffer at least 10 ft. wide separates the turf from the water or 2) a spreader guard, deflector shield, or drop spreader is used and the fertilizer is not applied less than 3 ft. from water.
Interested in learning more about lawn care and environmentally responsible practices? Check out the Michigan State University Extension home lawns website for articles, recommendations, and resources.
A version of this article originally appeared in the April 2023 issue of the Lakefront Lifestyles magazine.