May is a good time to feed your lawn. Lawns are growing faster than we can mow, quickly using up the last of winters reserves. Warmer soils mean those little soil critters that help break down nutrients in fertilizers are waking up, ready to eat.
Organic slow-release fertilizers depend on these soil microbes to break down nutrients, making them available to plants. It is this process that makes slow-release fertilizer last longer in the soil to give plants a steady source of nutrients. Slow-release fertilizers also are preferable because they are less likely to run off lawns to pollute lakes, rivers, streams, and Puget Sound. They are also less likely to move down through soils and contaminate our drinking water. To find slow-release fertilizers, look for terms slow-acting or long-lasting on labels. Read the fine print slow-release fertilizers have at least half of their nitrogen in the form of water-insoluble nitrogen. Most organic fertilizers are slow-release, including aged manure, seed meal, bone meal, poultry and fish by-products.
Also, leaving grass clippings on the lawn, or mulch mowing, provides nitrogen every time you mow. This can cut back the amount of extra fertilizer needed.
A big advantage to selecting organic slow-release fertilizers is they do not contain toxic weed or bug killers that other products may contain. Harmful weed or bug killers destroy soil microbes that live in healthy soils. Healthy lawns need healthy soils just as any other plant does.
Ideally, weeds are pulled quickly, before they go to seed. But if you wait to deal with weeds until it is time to fertilize with a weed or bug killer once or twice a year, weeds have the chance to go to seed and spread rapidly.
On the other hand, if lawns are mostly weeds, fertilizing is not necessary at all! Instead, choose long-handled weed tools to get tap roots and all. Always plant grass seed after you pull weeds to prevent new weeds from taking over the empty spaces.
If weed killers are used, choose a product that can be spot sprayed directly on weeds rather than spread over an entire area. This helps prevent weed killers running-off lawns and getting into water.
Thurston County is lucky to have garden centers that provide high quality, organic slow-release fertilizers. These nurseries are staffed with people who specialize in yard care. They are a great place to select slow-release fertilizers and ask for help controlling weeds in a non-toxic manner.
HazoHouse is the safe place to dispose of unwanted fertilizers and bug or weed killers that can be harmful to people, soil, and water if thrown into the trash. Please take responsibility for unwanted hazardous materials and take them to HazoHouse at the Thurston County Waste and Recovery Center, 2418 Hogum Bay Road in Lacey, open 8 a.m. to 5 p.m. Friday through Tuesday. For more information, visit www.co.thurston.wa.us/solidwaste/hazardous/haz-hazohouse.htm or call the Waste Line at 360-786-5494.
For more information on Common Sense Gardening, including a fertilizer fact sheet, go to www.co.thurston.wa.us/health/ehcsg or call 360-867-2674.
Dr. Diana Yu is the Health Officer for Thurston and Mason counties. Reach her at 360-867-2501, firstname.lastname@example.org, or @yu4health on Twitter.