Fertilizing lawn | Applying lawn fertilizers

Helping You Become a More Successful Gardener

Think of your turfgrass like a teenage boy – hungry all the time and readily able to convert nutrients to energy. Not many plants can take the regular – often severe – pruning that turfgrass does and still bounce back with such vigor and verve. But like a teenager, turfgrass needs a little help to meet all its nutritional needs.

Proper fertilization, in addition to good lawn care practices, can keep your turfgrass healthy and help boost your home’s curb appeal.

Before you can feed your lawn properly, you need to find out what nutrients it requires. A soil test can help you determine the precise methods and amounts of fertilizer needed to correct any deficiencies in your lawn’s soil. For example, if you find out that your turf is low in the three major elements (nitrogen, phosphorus and potassium), use an all-purpose fertilizer. But if your lawn is only primarily deficient in nitrogen – the most common condition – use a fertilizer that delivers an extra boost of that element.

How can you tell what’s in each fertilizer? Just look at the packaging. All fertilizers have an analysis of their contents by percentage of weight right on the package. These typically appear as three so-called N-P-K numbers, which are separated by dashes, like 20-10-5. The numbers relate to the amount of nitrogen (N), phosphorus (P) and potassium (K). In this 20-10-5 example, the fertilizer mix contains 20 percent nitrogen, 10 percent phosphorus and 5 percent potassium. The remaining 65 percent is inert fillers.

Another factor in determining the amount of fertilizer you need depends (at least in part) on your turf type: warm- or cool-season grass. The type of turf also helps determine when to fertilize: For most grasses, late spring or fall are the best fertilizing times, although warm-season grasses require a continual boost from late spring through autumn, and even into winter. And whatever you do, do not fertilize cool-season grasses in midsummer.

The types of fertilizers you use and how frequently you use them are often a matter of personal philosophy. Next to pesticide use, nothing in lawn care is quite as controversial as fertilizer. Many gardeners swear by the simplest fertilizing techniques. For example, cutting your grass with a composting mower and leaving the clippings on your lawn can provide ⅓ -½ of its nitrogen needs for the year. Dethatching and aerating also do a lot to keep the soil’s microbe and worm populations thriving, releasing mineral nutrients naturally from the soil.

When you do need to add fertilizer beyond these basic lawn care strategies, you’ll find that fertilizers are available in a wide range of forms. Three popular varieties are bulk granule, water-soluble (foliar) and dry concentrate fertilizers. Follow the step-by-step photos and their captions to learn how to apply each correctly.

Combined with good lawn care practices, fertilizing will give your lawn that extra boost it needs to grow lush and healthy. Ultimately, the best and most responsible fertilizing choices and techniques are the ones you make with the health of your lawn and the environment in mind.

Applying Granular Fertilizer

Applying Granular Fertilizer - Step 1

Granular lawn fertilizer should be applied with a drop spreader. Measure the amount needed per label instructions, then set the flow- rate adjustment on your spreader to ½ the package-label recommended rate (because you’ll be making two passes with your spreader).

Applying Granular Fertilizer - Step 2

Apply the fertilizer in two passes, applying the second at a right angle to the first to ensure even coverage.

Applying Granular Fertilizer - Step 3

Water immediately after fertilizing your turfgrass lawn. This dilutes the granules to avoid foliage burn and distributes nutrients to the roots, where they can be absorbed.

Applying Water Soluble Fertilizer

Applying Water Soluble Fertilizer - Step 1

Apply a water-soluble lawn food on a day that’s not windy. Following all label instructions, fill a hose-end sprayer with the dry powder, and set the flow-rate adjustment according to the package-recommended rate. (Note: Always wear gloves and protective clothing when mixing or applying any garden chemicals.)

Applying Water Soluble Fertilizer - Step 2

Attach the sprayer to the hose and seal the top.

Applying Water Soluble Fertilizer - Step 3

Spray the lawn food evenly across the grass in overlapping passes, avoiding flower beds and trees. (Lawn food contains much higher concentrations of nitrogen than what’s typically used to fertilize other plants.)

Applying Concentrated Dry Fertilizer

Applying Concentrated Dry Fertilizer - Step 1

Apply concentrated granular fertilizer with a rotary handheld spreader. Fill the spreader according to label instructions.

Applying Concentrated Dry Fertilizer - Step 2

Set the flow-rate adjustment on your spreader to ½ the rate recommended on the package label. Make two sets of passes across the lawn, with the second at a right angle to the first, rotating the handle of the spreader to spray fertilizer granules.

Applying Concentrated Dry Fertilizer - Step 3

Water the concentrated fertilizer into the turf, applying at least 2 inches of water to the lawn surface. The watering will carry the fertilizer down into the grass roots, where it will be absorbed.

Warnings

When mixing or applying any chemicals, always wear gloves and protective clothing, and always follow instructions and warnings on the label.

Facts

Hose-end sprayers filled with lawn fertilizer may be convenient, but they’re pretty inefficient. They hold, at most, a quart of water-soluble material – only a portion of which is nutrients. That’s less than a pound of fertilizer spread as far as the bottle lasts when you spray. It’s far better to apply dry fertilizers to your lawn: Most grasses need 1-2 pounds per 100 square feet, a far greater volume than what a hose-end sprayer can provide.
The miracle of compost is it’s the end result of biologic processes: growth, decay and the breakdown by bacteria. As a result, compost contains all that the plant material and the microbes brought to the party: basic nutrients, micronutrients and trace minerals. In other words, it’s a complete food. Topdressing your lawn during the beginning of dormancy brings all these good things to your lawn, improving its health.

Faqs

Q: What is synthetic fertilizer?
A: It’s mostly filler. So if you add the percentages by weight of the nitrogen, phosphorus and potassium, you’ll rarely find more than 25 percent of that fertilizer is nutrients – and sometimes much less. Next, look at the so-called “active ingredients” on the label. Some usual sources of vital plant nutrients are potassium chloride, ammonium chloride, phosphoric acid, urea and other industrial chemicals.

Next Steps

Understanding Fertilizer Numbers: N-P-K
Learn what the numbers on a fertilizer label represent and how each number affects plant growth and development.
Multipurpose Fertilizers: Are Additives Worth the Costs?
Slow-release fertilizers and combination fertilizers often cost more. It’s up to you, as an educated consumer, to determine if the cost is worth the convenience.
Detach Lawn Thatch
While some thatch on your lawn is good, too much will send your turfgrass down the road of slow decline. Learn how to identify potential thatch trouble, as well how to eliminate it so water and nutrients can get to the root of the problem.

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