Did you know that a vigorously growing, watered lawn from which the grass clippings are removed needs more added nutrients than a lawn that is not watered during the summer and where clippings are left on the lawn? Leaving lawn clippings on your lawn provides half of the nitrogen your lawn needs each year. By hauling away your grass clippings you are depriving your lawn of a natural fertilizer that can make your grass greener. Besides, raking or bagging, and then disposing of your grass clippings is a lot of extra expense. A half-acre of lawn produces more than 3 tons of lawn clippings, nearly 260 bags, each year. That’s a lot of bags! .

Cutting the lawn with a lawnmower set at a proper mowing height is important. In addition, cutting the lawn stimulates growth and increases thickness. Mow when your grass is dry, and never cut it shorter than 2-1/2 inches or remove more than one third of the leaf surface at any one mowing. Taller grasses create deeper roots, improving water infiltration and reducing runoff. A taller grass will also stay greener longer during droughts.

If you cut your lawn too short, you can stress it out; leading to weaker plants and a thinning of the lawn. As it becomes less dense, it is less able to compete with weeds. This is especially important during the summer because severe scalping can lead to irregular patches of the lawn dying.

Reducing the size of your lawn by expanding or creating beds with native or drought-tolerant plants and trees has a multitude of benefits. For example:

• Beds can reduce the volume of stormwater, and help prevent runoff by acting as filters keeping fertilizers and chemicals on your lawn.
• Native or drought-tolerant plants that are appropriate for the conditions in your yard (soil type, amount of sunlight, etc.) often require little to no irrigation and fertilizer once established, saving you money and time.
• Native plants and trees can provide valuable habitat for wildlife, attracting birds and butterflies to your yard.
• Trees improve air quality, and reduce energy consumption by shading and cooling our homes.

Other Resources:

• Plants for a Livable Delaware (PDF)
• Livable Plants for the Home Landscape (PDF)
• Native Plants for Delaware Landscapes (PDF)
  
• Native Plants for the Mid-Atlantic 
• Native Plant Suppliers wholesale/retail

A soil test will identify common nutrient deficiencies in plants, and can provide information on the proper amount of lime and fertilizer to apply to your lawn, garden, or beds. Soil testing is the only way to determine the proper ratio of nitrogen, phosphorus, and potassium to apply to a lawn.  By applying only as much lime and fertilizer as is necessary and at the appropriate time, runoff into surface or ground water is minimized, money is saved, and plant health is optimized. However, a soil test is only as reliable as the sample you take.

When selecting fertilizer, you will find three numbers on the bag: the first number is the percentage of Nitrogen (N), the middle is Phosphorous (P), and the third is Potassium or Potash (K). Select a fertilizer that is low or no phosphorous. Because of the concern for excessive phosphorus in our waterways from fertilizer, many states are passing, or have passed, laws that restrict the application of phosphorus fertilizer to established turf. Select a fertilizer that contains 50% or more of the nitrogen in a slow-release form. Slow-release nitrogen lasts longer which provides a steady supply of nutrition throughout the growing season. This information can be found in the “Guaranteed Analysis” section on the back of the bag.

Other Resources:

• Soil Sampling for the Home Gardener
  
• University of Delaware Soil Testing Program
  
• Agro Lab Soil Testing
  
• A Homeowner’s Guide to Fertilizer
• Video: How to Read a Fertilizer Bag and Choose a Fertilizer

Use no more fertilizer than is necessary for the size of your yard.  Too much fertilizer can actually weaken your lawn, making it more susceptible to pests, weeds, and disease. To avoid purchasing and applying too much fertilizer, you need to carefully measure your yard to determine the square footage.

To calculate the amount of fertilizer to apply 1 lb N to 1,000 square feet:
(100 ÷ % of nitrogen in fertilizer bag) x (square footage ÷ 1,000) = lbs. of fertilizer to apply

Be certain to READ the instructions. This is vital for any type of lawn fertilizer. Make sure you know what you’ve purchased, how and when to apply it, and how long to wait before watering. Lawn fertilizers should have clear instructions and warning labels.

Most homeowners use a spreader, drop or rotary, to apply granular fertilizer. While either is sufficient, a rotary spreader is less likely to leave a striped pattern on the lawn showing areas that were missed.  It’s wise to spread each fertilizer application in two directions. 

Lastly, if you don’t feel comfortable undertaking this on your own, hire a professional. They’re happy to help. 

Other Resources:

• Measuring your lawn (PDF)
  
• A Homeowner’s Guide to Fertilizer
  
• Fertilizing Lawns
  
• Video: How to Read a Fertilizer Bag and Choose a Fertilizer
  
• Video: How to Apply Fertilizer
  
• iPhone Fertilizer Calculator App 

Always be sure to sweep excess fertilizer back into the lawn. When runoff and drainage waters carrying applied nutrients move over paved surfaces (streets, parking lots, etc.)  there is no soil to act as a filter and it may flow directly into our waterways.  Even houses that are not beside a stream or lake can contribute to the problem. Storm drains found in most local neighborhoods are designed to move runoff from your neighborhood to the nearest body of water. Though many people believe otherwise, storm drains do not carry stormwater to wastewater treatment plants but instead, flow UNTREATED directly into our rivers and streams.

Grass clippings not left on the lawn, leaves, and other plant debris should be removed as soon as possible from street gutters, sidewalks, and driveways. Grass clippings may also cause unwanted growth of algae and aquatic weeds. This plant material can be composted, used in the garden as a mulch, or disposed of through appropriate yard waste sites or community services.

Most homeowners make sure not to miss the traditional springtime fertilizer application. However, the best times of year to fertilize your lawn is late summer and fall. Early spring applications of nitrogen cause a surge of top growth in the plants. This makes the lawn look nice in the spring, but it actually depletes the plants’ energy reserves causing the grass to weaken and less apt to survive periods of stress in the summer. If you apply fertilizer in late August or early September, you will provide your lawn with adequate nutrition to overcome any summer stresses. In addition, an application of fertilizer in late October or early November will ensure earlier green-up in the spring without stimulating excessive shoot growth.

See the chart below for assistance:

Do not fertilize or mow adjacent to waterways by leaving a "ring of responsibility" of approximately 10 feet.  Leave a “buffer zone”—a strip of unmanaged grasses or natural vegetation—to grow around the shoreline. This vegetation will help prevent soil erosion and will also remove and retain some of the nutrients that would otherwise enter the waterway. The consequences of nutrients getting into our waterways can often be serious. Blooms of algae can be caused by too many nutrients in our ponds, lakes and bays. Not only is this algae unpleasant to look at and smell but it also can cause fish kills because of the algae is consuming all the dissolved oxygen necessary for the fish to live. Algae blooms can have a negative effect on recreation, the economy and human health.