Healthful soils are the building blocks for healthy plants, teeming with beneficial microorganisms, insects and worms. These soil creatures create a loose soil structure that allows air, water and plant roots to reach into the soil. They recycle nutrients to make them available for plants, and even protect from pests and disease. Those tiny guys are doing a ton of work.
Weed and bug killers can destroy these organisms, creating weaker plants and setting up a need for more weed and bug killers. Feed the soil with organic matter, avoid the use of weed and bug killers, water grass no more than an inch per week and allow your yard to thrive.
Fertilizers can be helpful for plants, including grass, but while a little can help, too much can be harmful. Soil tests can help determine the nutrient needs for each area of the yard, allowing for the most efficient use of fertilizers and additives such as lime. Contact Thurston County Environmental Health at 360-867-2674 or visit our website (co.thurston. wa.us/health/ehcsg) for a list of local soil test providers.
Plants take up most of their soil-based nutrients in the top 6 inches of the soil. Fertilizers that are quick-greening tend to have high levels of water-soluble nutrients that quickly wash out of the reach of plant roots. The nutrients do not last long in the soil, leaving plants hungry for more. The washed-away fertilizer can then pollute lakes, streams, Puget Sound and groundwater – our source of drinking water.
The best fertilizer for plants is slow-release, sometimes called long-lasting. Slow-release fertilizers have at least half of their nitrogen in the form of water-insoluble nitrogen. The nutrients in slow-release fertilizers stick around in the soil and are available for plants as needed.
Slow-release organic fertilizers need the warmer soils of May through October when soil critters are active. It is those soil critters that help make nutrients available to plants at a usable rate. These fertilizers are better for plants and water quality because they last longer in the soil and are less likely to run off into lakes, rivers, and Puget Sound.
Choose fertilizer that does not contain weed or bug killers. If you have a weed or bug problem, choose something that will take care of that specific problem and apply it only to the areas that need it.
“Grow Smart, Grow Safe” is a guide that can help you choose products that are safer for your family, your pets, wildlife, and our shared water resources. Find it at growsmartgrowsafe.org or call us at 360-867-2674 to request a copy.
Dr. Diana T. Yu is the Health Officer for Thurston and Mason counties. Reach her at 360-867-2501 or yud@co.thurston.wa.us.
