Elisabeth C. Miller Library

Gardening Answers Knowledgebase

Knowledgebase record #419

PAL Question

I am looking for general information on lawn care, lawn renovation, lawn fertilizer and alternatives to pesticides.


Here is information from the web pages of Seattle Public Utilities. An excerpt:

Fertilize Moderately:
Use "Natural Organic" or "Slow-release" fertilizer. These fertilizers release nutrients to feed the lawn slowly, and less is wasted through leaching or runoff into our streams. Look for the words "natural organic" or "slow-release" on the bag.

Fertilize in September and May:
With slow-release or organic fertilizers, you can fertilize just twice a year, in mid to late May and again in early September. If you choose to fertilize only once, the fall application is most important because it helps the grass grow new roots and store nutrients for next year's growth.

How much to apply:
Washington State University (WSU) recommends that home lawns receive 3 to 4 pounds of nitrogen (in a balanced fertilizer) per 1000 square feet of lawn each year. Grasscycling can supply at least one-quarter of that. Split the rest between the May and September applications. Avoid fertilizing in the early spring because it makes lawns grow too fast (unless your lawn needs help recovering from disease or insect damage.) Wait until May.

Mow better:
Grasscycling returns valuable nutrients to the soil every time you mow! Mow high, mow often and leave the clippings to see results.

Fertilize for a healthy colored lawn"
Healthy lawns are a medium green color (top), depending on the variety of grass. The darkest green turf (bottom), which many people strive for, is not in fact the healthiest turf. Overfertilized lawns are more prone to disease, thatch buildup, and drought damage.

Test for calcium deficiency:
Soils west of the Cascades are often low in calcium. Apply lime in the spring or fall if a soil test shows a calcium deficiency or acid soil conditions (pH less than 5). Call WSU Cooperative Extension (206) 296-3900 for information on soil testing and their Home Lawns bulletin."

If you would like to renovate your lawn, this is something you could do in the fall. Local garden writer Ann Lovejoy describes her method in The Handbook of Northwest Gardening (Sasquatch Books, 2003):

  • Mow the existing grass as short as possible.
  • Spread 1 inch of clean crushed quarter-ten gravel (not pea gravel) evenly over the entire surface.
  • Spread 1 inch of compost over the gravel.
  • Top-seed with a regionally appropriate blend if the lawn is thin and spotty.
  • Wait 6-7 weeks before mowing again.

Should you decide to start afresh, here is information from the Washington State University Extension website which discusses grass seed for Western Washington gardens. Here is an excerpt:
What Grass Seed Grows Well in Western Washington?
"To establish a lawn in western Washington, choose a combination of turftype tall fescue grasses and turftype perennial rye grasses. A mix that adds up to about 90% of these two grass seed types will grow well in either sun or light shade in western Washington. Turftype perennial ryegrass takes full sun and stands up to traffic. Turftype tall fescues are adapted to shadier locations. In combination, the mix works for a lawn in average light conditions. Mixes containing fine-leaved fescues or chewings fescues will also establish well. Fine-leaved fescues offer bright green color, and will take some shade, but do not take heavy use.

"Many commonly-grown grass types from other areas of the United States will not thrive in western Washington's cool, dry summer climate. AVOID mixes with high concentrations of Kentucky blue grasses. DO NOT PLANT Zoysia, bermuda, dichondra, centipede, carpetgrass, St. Augustine, or mondograss. Buffalograss isn't suitable for western Washington, though it may thrive in eastern Washington.

Soil Conditions for Planting a New Lawn:
"Establishing a new lawn successfully depends more on the preparation of the ground before planting than on whether the lawn choice is seed or sod. Lawn failures are often caused by poor soil conditions under the roots. Many times soil surface left for planting after new construction is infertile subsoils, with rocks, lumps, and building detritus left in it. The texture may vary from sands and gravels to heavy, poorly drained clay areas. The best soil texture for a lawn is a sandy loam, containing 60%-70% sand and 30%-40% combined silt and clay."

If the soil isn't well-drained, do not try to amend a heavy clay by dumping sand into it. Adding sand doesn't work, nor does adding gypsum. Amend the soil with organic material, which will help in creating better structure. Use compost, manure, aged sawdust, ground bark, or other organic (previously living) materials. Spread 2 inches on top of the ground and work it in thoroughly 6 to 8 inches down. Getting it completely incorporated is important, because spots of organic material in clumps may decompose and cause a low spot in the finished lawn. Rake away clods and remove large rocks and litter.

University of Minnesota Extension's Caring for Shoreland Lawns and Gardens describes best practices for caring for a shoreline lawn and garden, which includes using compost as lawn fertilizer. An excerpt:

  • If possible avoid the use of chemical fertilizers. Native vegetation does not require the application of additional fertilizer. Use caution if applying fertilizers to lawns and adhere to the following guidelines:
    Have your soil tested to determine how much fertilizer is needed and minimize the use of chemical fertilizers; soil test sample bags are available through the county offices of the University of Minnesota Extension Service.
  • Use compost or manure; this is preferable to chemical fertilizer. However, these also have the potential to damage water quality if used in excessive amounts.
  • If chemical fertilizers are used, select slow-release (water insoluble) forms; see recommendations for fertilizing on next page.
  • Water your lawn after fertilizing, but do not allow excess water to run off into surface waters.
  • Sweep up any fertilizer spilled on hard surfaces such as walks and driveways, instead of washing it off.
  • Use extra caution when applying fertilizer near surface waters; do not spread fertilizer within 75 feet of surface waters or wetlands; use a "drop" spreader and not a "cyclone" spreader to minimize the possibility of getting fertilizer directly into the water.
  • Never apply fertilizers to frozen ground.
  • Leave a natural vegetation filter strip of grass, trees, and/or shrubs next to the shoreline; another option would be to construct a berm along the shore.

You may find this general information about compost, from the City of Seattle Public Utilities and the Saving Water Partnership, of interest.

Here are additional links to lawn care methods. The first three are from the Northwest Coalition for Alternatives to Pesticides:

Taking Care of Your Lawn without Using Pesticides.

Dealing with Dandelions.

Pesticide-Free Techniques for Dealing with a Mossy Lawn.

From Toxic-Free Future (formerly Washington Toxics Coalition):
Choosing Fertilizers for the Lawn & Garden.

From Beyond Pesticides:
Read your "Weeds"--A simple Guide to Creating a Healthy Lawn.

Keywords: Weed control, Lawns and turfgrasses, Lawns--Care and maintenance
Date: 2007-04-20

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