Lawn Fertilizers

The hallmark of a healthy lawn is a deep green color and the ability to grow back after normal wear and tear and regular mowing. Sometimes, however, grass needs some extra help in the form of nutrients that are not readily available in the soil to stay healthy. In this case, you can apply a lawn fertilizer that will revitalize and enrich the soil, providing your grass with the nourishment it requires. Lawn fertilization is not difficult and almost any homeowner can quickly learn the right type of fertilizer to buy and how to apply it properly. Fertilizer can help you grow a lawn that is dense enough to fight weeds while standing up to disease, insects and foot traffic. Before you buy lawn fertilizer, consider the following questions:

• Are you fertilizing cool-season or warm-season grass?
• When should you begin fertilizing your lawn for best results?
• How much fertilizer should you apply each season?
• How do you avoid burning your lawn with fertilizer?
• Do you prefer organic fertilizer over synthetic varieties?

Types, Methods and Application Tips

Like all fertilizer, lawn fertilizer contains three main ingredients -- nitrogen, phosphorus and potassium. The percentages of these nutrients are represented by the three numbers on each fertilizer label, such as 20-10-10 (20% nitrogen, 10% phosphorus, 10% potassium). Nitrogen is the primary nutrient that helps a lawn green up and is present in both water-soluble and water-insoluble lawn fertilizers. Once you choose a fertilizer that works for your lawn, there are several methods for application, based upon the type and whether or not you want to invest in a fertilizer spreader. For best results, you'll want to follow a few guidelines for application, making sure to always consult the manufacturer's recommendations located on the fertilizer bag for more specific instructions.

Types: The two main types of lawn fertilizer, water soluble and water insoluble, relate to how nitrogen is released into the soil. Water-soluble varieties dissolve readily into water and act quickly, releasing nitrogen into the soil immediately upon contact. The result of water-soluble formulas is that grass greens up fast. However, the fertilizer is used up quickly and must be reapplied. As nitrogen in these fast-release fertilizers dissolves, it temporarily acidifies the soil in your lawn, which can affect organisms that normally keep grass healthy. Water-insoluble formulas do not dissolve in water, so nitrogen is distributed steadily and consistently over time. Water-insoluble, or slow-release fertilizers, do not affect soil life, so they are generally considered gentler on grass.

• Water-soluble fertilizers are released quickly within 2 weeks time
• Water-insoluble fertilizers are released slowly over 8 to 10 weeks time
• Water-insoluble fertilizers include both organic and synthetic varieties
• Slow-release fertilizers cost more but save time in maintaining your lawn
• Synthetic, coated fertilizers are less expensive than natural varieties

Methods: There are several different ways you can apply fertilizer, depending upon the type you choose, how much time you have to maintain your lawn and how much money you want to spend on spreaders. Broadcast spreading is the most popular method and involves spreading fertilizer over a wide area using a handheld broadcast spreader or a walk-behind type with wheels. Drop spreading works like a walk-behind broadcast spreader except that it drops fertilizer directly down to the width of the spreader base. Organic spreading varies as some organic fertilizers must be applied by hand or with shovels and rakes. Spraying is unique to liquids and operates by using a garden hose affixed to a bottle of liquid fertilizer.

• Broadcast spreading with a walk-behind spreader distributes a large amount of fertilizer
• Use handheld spreaders on small yards or patches and to apply weed control to smaller areas
• Drop spreading takes more time but is more accurate than broadcasting
• Liquid spraying provides immediate results but can be difficult to apply evenly
• Organic spreading by hand requires more time and attention to detail

Application Tips: While you always want to follow the manufacturer's instructions on the fertilizer package, there are a few general tips that apply to all fertilizers. For example, always water your lawn well after you fertilize. Raking also helps distribute the fertilizer, especially with granules, allowing the fertilizer to sink into the lawn. The best time to fertilize is when your lawn is periodically being rained on or watered. Fertilizing during drought conditions can burn your lawn if there is not enough moisture present for the chemicals to work properly. Make sure you always rinse your spreader off after use as fertilizer can eventually eat away metal parts. 

• Fill your spreader on a sidewalk or driveway to avoid spills, which lead to fertilizer burn
• For handheld or liquid spreaders, walk backwards so you can see where the fertilizer is distributed
• With walk-behind spreaders, work from the edges first, then spread back and forth
• With drop spreading, overlap the width of the wheel base to ensure equal coverage
• For organics, take time to spread or rake each area to achieve uniform spreading

Grass Type	Season	Quantity	Application
Cool Season (Northern climates)	Spring, fall	Approximately 2 lbs. of nitrogen to 1,000 square feet*	Use less nitrogen during the spring growing season Use larger amounts of nitrogen during the fall growing season when temperatures are more even and the danger of drought has passed Add weed and pest control products mid summer, if needed Water thoroughly after spreading
Warm Season (Southern climates)	Spring,late summer	Approximately 2 to 4 lbs. nitrogen to 1,000 square feet*	Fertilize soon after lawn becomes green in the spring and danger of frost has passed Fertilize again during late summer months Use less nitrogen during the fall growing season Use larger amounts of nitrogen in early to late spring Use weed control products in mid to late spring Water thoroughly after spreading

*Note: Based on slow-release fertilizers -- for fast-release formulas, use approximately 1 lb. of nitrogen per 1,000 square feet.

Features

Organic: Organic lawn fertilizers are made from once-living organisms and their byproducts. The nitrogen in organic fertilizer breaks down and is released slowly. Organic fertilizers can help make your lawn more densely populated, improving the texture and appearance. They work best in warm, moist growing seasons.

Synthetic: Synthetic fertilizers are manmade from chemicals and deliver a faster greening effect. This type of fertilizer tends to penetrate soil quickly and is easy to use. Because synthetic fertilizers work quickly, the effects do not last as long and you may need more frequent applications. Synthetics can also burn your lawn if not applied according to directions.

Granular (Dry): Because they are easy to use and last longer than other varieties, dry fertilizers are more popular than other types. Granular fertilizers are powders or granules that are mixed with water and come in both slow-release and fast-release formulas to make nutrients available to your lawn.

Slow-Release: Slow-release fertilizers work by slowly releasing nutrients through a permeable coating around dry granules or pellets each time the lawn is watered. Because water is needed for activation, application of slow-release fertilizer is somewhat weather dependent. This type also releases best in warm weather. Slow-release fertilizers can last in soil for 2 to 6 months, which is one reason why these types are usually more expensive and are much easier to maintain. Additional advantages include a decreased chance of fertilizer burn and ease of use due to fewer required applications during a growing season.

Fast-Release: Because fast-release fertilizer supplies nutrients to your lawn more quickly than slow-release types, they show results more quickly. Fast-release fertilizer costs less on average but may need more frequent application than slow-release types.

Liquid: Available as a highly concentrated liquid, these lawn fertilizers are sprayed on using a garden hose. Liquid fertilizer is easy to apply and spread evenly, reducing the risk of fertilizer burn. Also, liquid fertilizers work quickly and are easily absorbed into grasses' root systems for immediate results. Because it leaches into soil, liquid plant food needs frequent reapplication compared to other types, which can increase cost, especially if your lawn is large.