Don’t Fertilize Your Lawn in April
By Gil Medeiros, Fairfax Master Gardener
Everyone, it seems, wants you to fertilize your cool-season lawn in April. Fertilizer companies bombard you with their slick, sophisticated, sometimes entertaining television ads. You turn off the TV, but it still doesn’t end. Whenever you walk into a big-box hardware store to buy a furnace filter, you must walk past the colorful displays of plump lawn-fertilizer bags.
Resist. For the good of your fescue, bluegrass, and perennial rye, resist.
Here’s why: In the early spring, as most plants awaken from dormancy, they want to grow roots. Grass is the same. This priority is hard-wired into the DNA of the plant. It is the accumulated wisdom of eons of survival. The grass sends its roots deep into the soil because summer is coming; the rain may stop, and the heat is certainly on the way. The timing of this root-growth spurt is not the same everywhere. It is governed by climate, which is a function of longitude and latitude. Therefore, the major advertisements of nationally marketed fertilizers, and the splashy promotions in the big-box stores are correct for some parts of the country. Not here. In Fairfax, the fescue and bluegrass awakens to push out new roots in April and early May.
What happens when you feed the grass in April with a lawn fertilizer that contains 20 to 30 percent nitrogen? Nitrogen helps plants grow green, leafy shoots; that’s the part of the grass plant above the ground. When the plant is growing shoots, it slows and eventually shuts down the growth of roots. Root growth is, therefore, stunted as the grass plants take advantage of nitrogen availability to grow luxurious, green, top growth. After fertilizing you feel secure in the knowledge that you have done the right thing by your lawn. It has never looked happier. It appears that Sandy Scott on the Masters golf telecast was right.