Just weeks ago it felt like Michigan had become the new Arctic Circle with temperatures hovering at zero for…too long. Then we had a very well deserved 70 degree day in mid March…which was only one day, but it meant spring is coming, and now its here! Garden centers and television advertisements are already encouraging us to get out and fertilize our lawns, with one of the first being aired while we were yet buried by snow. After the snow has melted, there may still be significant frozen ground, often until early April.
So what are you to do? Be patient, which can be very difficult to do. But first, understand that frozen soil should never be fertilized. Fertilizer particles are not going to green up a lawn while the ground is still frozen. These tiny pellets can be washed off the frozen turf into storm drains after a rain storm, damaging lakes, streams and rivers with unnatural plant and algae growth.
Once soil temperatures begin to warm in spring, grass roots break dormancy and begin growth well before the grass blades start to green up. Turf root system development in early spring is critical for grass health. Deeper roots that form in spring help the vigor of the turf during summer’s hot and droughty conditions. Fertilizing in early spring can encourage lush top growth at the expense of root growth. Our desire for a green lawn early in spring is not always best for overall turf health.
A turfgrass fertilization guide from Pennsylvania State University states that high rates of nitrogen on the turf in early spring encourages excessive foliar growth, which uses up carbohydrate reserves meant for root development and disease resistance. Michigan State University Extension’s Lawn Care Tip Sheet advises avoiding fertilization until May. This may be counter to the advertisements we hear on the television promoting combination products that fertilize the lawn early in spring and are also meant to control crabgrass.
Additional tips on crabgrass and snow mold can be found here.
Have a great Spring!