THE IMPORTANCE OF FERTILIZING

Your soil supplies some of the nutrients that turfgrass needs. Most soils are not able to provide all of them during the entire growing season. A healthy and actively-growing lawn uses a great deal of energy. Fertilizer helps your lawn stay healthy by: 

 

•  Promoting new leaf and root growth. 

 

•  Aiding in the recovery from foot traffic and pest damage. 

 

•  Reducing and controlling weeds. 

 

•  Replacing nutrients lost to leaching, volatilization and grass clipping removal. 

 

Fertilizer Types 

Fertilizer is available in two types: liquid and granular. Choose the one that meets your lawn's needs in the form that is easiest for you to use. Liquid fertilizers are fast-acting. Since they are quickly absorbed, they require application every 2-3 weeks. Most are mixed with water prior to application with a garden hose attachment.

 

Granular fertilizers are applied with a spreader and must be watered into the grass. Granular fertilizers are easier to control because you can actually see how much fertilizer you are using and where it is being dispersed. 

 

Granular fertilizers are produced in two different formulations, quick-release and slow-release. 

 

Quick-release fertilizer typically lasts for three to four weeks, depending upon the temperature and the amount of rainfall. For general use, these water-soluble nitrogen fertilizers (WSN) are also known as commodity or field grade fertilizers. 

 

There are two main types of slow-release fertilizers, known as water-insoluble nitrogen (WIN), available for specific applications: sulfur coated, which lasts for about 8 weeks, and polymer coated, lasting about 12 weeks. 

 

Both time estimates may vary depending upon the amount of rainfall. To avoid unwanted growth stimulation, do not apply slow-release fertilizer late in the growing season. 

 

Breaking the Code: How to Read a Fertilizer Label

The three numbers (often called NPK) on a fertilizer package tell you the percentage of the base elements nutrient makeup by weight. These percentages in fertilizer compounds are formulated for everything from asparagus to zinnias. The three main components are: 

 

•  Nitrogen (symbol N) for leaf development and vivid green color

 

•  Phosphorous (symbol P) for root growth

 

•  Potassium (symbol K) for root development and disease resistance. 

 

For example, a bag marked "16-4-8" contains 16 percent nitrogen, 4 percent phosphorous and 8 percent potassium. The other 72 percent is usually inert filler material, such as clay pellets or granular limestone. To know how much of each is in the bag, multiply the percentage by the size (weight) of the bag. For example: a 50 lb. bag of 10-10-10 contains 5 pounds each of nitrogen, phosphorus and potassium.

 

There may also be secondary elements such as calcium for root growth, magnesium for sugar formation, and sulfur for green color. The minor elements that may be present are zinc, iron, manganese, copper, molybdenum and boron. 

 

Weed and Feed and Pre- or Post- Emergents Weed and Feed

"Weed and Feed" is a common term which refers to fertilizer that contains weed killer for broadleaf weeds such as dandelions. 

Pre-emergents, such as those commonly used to prevent crabgrass, are weed killers which must be applied before the weeds germinate. They are ineffective if the weeds are already actively growing. Pre-emergent weed killers are often mixed with fertilizer and are designed to be spread in early spring. Crabgrass normally germinates when the ground temperature reaches 60° F — the ground temperature at which dogwood trees start to bud and forsythias begin blooming.

 

Post-emergent weed killers are contact killers, and are effective only if the weeds are already actively growing. They will not kill weeds which have not yet germinated. 

 

Timing of the application of pre-and post-emergents is critical for success. Applying these products too early or too late is essentially a waste of time. Read the package carefully before selecting to be sure which product fits your needs. 

 

Spring

In the spring, you may be tempted to help your lawn out with a nitrogen-rich fertilizer. While fertilizing in the spring is okay in moderation, this is a time of year to exercise restraint. That explosion of green may be pleasing to the eye, but what you're actually doing is encouraging outrageous top-growth to the detriment of your lawn's roots. A fertilizer that's lighter on the nitrogen and a little heavier on the phosphorus will encourage good strong roots. 

 

Summer

During the heat of summer, nitrogen is more likely to burn your lawn than during other times of the year. Nitrogen burn is particularly likely if your lawn is drought-damaged. To minimize the possibility of damage, look for a slow-release fertilizer, and hold off on fertilizing period if your lawn is showing signs of summer stress. 

 

Fall

Because fertilizer has a better chance at getting down to the roots in the fall--the part of your grass that really needs the nutrients--fall is the most important time to fertilize. Consider springing for a slightly more expensive fertilizer. Slow-release and combination fertilizers are generally better than fast-release fertilizers and are, as a result, a little more expensive. 

 

Lawn fertilizer done right will have a huge positive impact on your yard, spring, summer, and fall. 

 

The top time to fertilize trees extends from late fall, after the leaves have fallen, through the winter and into early spring before vigorous new growth occurs. Fertilizer applied in the fall has a longer time period to penetrate the soil enabling the roots to more efficiently absorb it. The fertilizer is taken up by the roots during the winter and is available to the plant for growth in the spring.