With all the information out there from fertilizer companies, turf specialists, and lawn experts, it’s hard to know if and when (and if) you should fertilize in the spring. Spring fertilization is recommended as part of a complete lawn and plant care program, along with cleaning up garden beds and applying mulch. The trick is to make sure you are applying fertilizer at the right time so that you don’t throw off your whole landscaping program.
Best Time for Spring Fertilization
When cool-season grasses “wake up” in the spring, they enter a natural growth cycle where the root system begins growing and building carbohydrate (energy) reserves. If you didn’t fertilize in the late fall, you’ll want to apply it in early spring to help the grasses and plants build up their root systems. But if you fertilized in the late fall, the slow release function of the fertilizer will still be lingering, providing extra green up in the early spring. In that case, rather than fertilizing in the early spring, it is better to wait until the late spring, just before the heat of summer begins. This will take advantage of the lingering fall fertilization application, and prepare the grass for summer when it slows down carbohydrate production and begins utilizing the reserves.
Do’s and Don’ts of Fertilizer Application
Many homeowners make the mistake of using the wrong type of fertilizer, too much, too often, and in the wrong areas. When it comes to fertilizer application, it’s important for both the health of your landscaping, as well as the environment, to know just how much to use, what type to use and where to apply it. For most lawns, a substantial feeding of 3/4-1.0 lb of slow-release nitrogen will allow the plant to re-build its energy (carbohydrate) reserves and ward off the stresses of summer-like drought, heat, traffic, disease, and insects. An IBDU or polymer-coated slow-release fertilizer can feed the grass for up to 12 weeks.
DON’T apply a fertilizer that’s high in phosphorus. Phosphorus washing into lakes and rivers can result in the explosive growth of algae. Besides, most lawns already have all the phosphorus they need.
DON’T use cheap, quick-release fertilizers. Nutrients in cheap fertilizers run off after heavy rain and don’t feed for long. Brand names contain more slow-release nitrogen, the most important nutrient for lawns, so they feed longer and pollute less.
DON’T fertilize dormant grass. Grass uses nitrogen for making grass blades, but if it’s not growing yet, you’re wasting your money and also adding to groundwater pollution. Wait until it greens up or until after the ground thaws and you see spring trees and shrubs blooming.
DON’T use fertilizer to melt snow and ice on sidewalks. Snowmelt will carry nitrogen from the fertilizer into groundwater and storm drains.
DON’T get fertilizer on sidewalks, driveways, and other pavement. Rain will quickly wash it into the gutter, storm drains, and water bodies. Sweep any stray fertilizer back into the grass.
DON’T fertilize more often than necessary. For warm-season grasses, fertilize once in spring and once in summer. For cool-season grasses, fertilize once in spring and once in fall.
It’s best to coincide any fertilizer application with a rainfall of at least 1/4″ to water in the product. A lawn fertilized with a slow-release fertilizer will not need to be fertilized for up to 12 weeks. And, before doing any fertilizer application, be sure to do a spring cleaning in your garden beds to clear away debris. After cleaning and fertilizing, apply mulch to help insulate the garden beds and allow the fertilizer to be absorbed slowly. This will ensure the fertilizer lasts longer, does not run off, and gives your plants the nutrients for the healthy growth you want.