We hear this question a lot. It would be nice if we could fertilize our lawns once and be done with it, just like it would be nice if we could mow once for the season and that would be it. In the real world, where your lawn provides a growing, natural setting for your home and a place for your family to relax and play, it needs a regularly scheduled fertilization program to reach its potential.
Grass that receives appropriate levels of fertilizer — not too little and not too much — produces a dense root and shoot system capable of filtering out impurities or other components that might be found in runoff.
Your lawn needs a balanced fertilizer with nitrogen, phosphorous, and potassium to keep it healthy and strong. Most soils have some of these elements present, but usually they become depleted over the years. Turf is a very hungry plant during its major growing seasons.
Proper fertilizing with balanced applications throughout the growing season promotes thick, dense grass that can resist disease and weed invasions. Applying too much of any one of the basic elements can cause erratic results. For example, an over abundance of nitrogen will cause rapid growth of the grass plants that the roots can't adequately handle; the blades become long and spindly. Balance is the key. As of yet, there is no magic pill for the perfect lawn.
Ideally, you should do a soil test before applying any fertilizer. Some areas have already high levels of phosphorous in the soil. In that case, additional phosphorus is not needed and could cause problems.
Depending on your growing season, a minimum of 3 fertilizer applications should be considered, depending on your location.
Spring (for warm season grasses)
Late Fall (for cool season grasses)
Aeration (either early fall or early spring, depending on your location and soil type)
Additional applications such as insect controls and pre-emergent weed controls might also be considered, especially if you had a strong infestation of either crabgrass type weeds or destructive insects.
Both methods have their strong advocates with convincing arguments that their method is best.
PROS: Liquid fertilizer applied to the grass blade and absorbed into the plants system takes effect quickly. Liquid fertilizer transfers from the grass blade to the grass roots where it is stored for future use. Some liquid fertilizer is applied to the soil surface where it gradually percolates into the topsoil layer over a period of time.
CONS: If heavy rain or watering occurs before the fertilizer has had time to be absorbed, some benefits of the application, may be dissipated. Liquid fertilizers are short lived compared to time-released granular applications.
PROS: Feeds grass plants the natural way, through the root system. Time release properties of the granular pellets provides long term benefits to the health of the grass plant.
CONS: Takes a long time for fertilizer to soak in. If heavy rains occur any time during the lifetime of the granular pellets, important nutrients may be washed away and thus becomes ineffective.
Professional lawn care providers have developed special formulations unavailable to the general public that use both methods. In other words, don't make a selection of a lawn care provider based on whether or not they use the granular or the liquid methods of applying fertilizers to your lawn.
Fertilizers are really just basic building blocks of our environment. However, we've come to identify these basic building blocks as either inorganic (synthetic) or organic.
Inorganic fertilizers are used in traditional lawncare. More correctly, inorganic fertilizers are better described as soluble fertilizers. This means all they need is water to be available for plant absorption.
Organic fertilizers have the same basic chemical make up as inorganics, except for this one important thing: they have not been processed to the degree that soluble fertilizers have been processed. For these organic fertilizers to be useful, they will need to go through an additional step before doing plants any good. That additional step is performed by microbes living in the soil.
Over fertilizing can aggravate pest problems, stimulate excessive growth and require frequent watering. In addition, when people use too much fertilizer on their landscapes, it can seep through the ground, past the root zone of the grass, plants or trees and into aquifers. It can also be washed off by rainfall directly into surface water or via storm water systems. Even time-release fertilizers can be over applied. Read and follow label directions carefully.