Natural Pest, Weed, and Disease Control

Think twice before using pesticides

Image of bird with a bug
Identify bugs before you spray, to protect birds and salmon.

Pesticides (weed and bug killers) can damage soil and plant health, poison wildlife like birds and salmon, and harm our families health. The good news is that we really don’t need those chemicals to grow a healthy, attractive landscape. Try these natural methods, and learn more in the Natural Pest, Weed & Disease Control Guide (English, PDF)

Start with prevention

  • Build healthy soil with compost and mulch – soil organisms protect plants from many disease and insect pest problems.
  • Select pest-resistant plants, and put them in the sun/shade and soil conditions they like.
  • Clean up diseased plants, and compost dead plants in fall to reduce hiding places for insect pests.
  • Pull weeds before they go to seed and spread.
  • Use a variety of plants, so if pests attack one plant, others can fill its place.

Identify the problem before you spray, squash, or stomp

The problem could really be incorrect mowing or pruning, improper watering, or other easily corrected practices. Or that scary bug could actually be a beneficial “good bug” that eats problem pests. Whether it’s a bug, disease, or weed, you need to identify it to know how to effectively manage it.

Accept a little damage – give nature time to work

Natural predators often bring pests under control, but they need time to work. Most bugs are good bugs: only about 5% of the bugs in your yard are pests. “Good bugs” like ground beetles, lady bugs, and lacewings help control pests. Don’t spray at the first sign of damage – nature may control it for you, or plants often just outgrow the damage.

If a pest or weed problem develops, use the least toxic solution

  • Physical controls like traps, barriers, fabric row covers, or repellants may work for pests.
  • Long handled weed pullers pop dandelions out easily.
  • Mulching once a year reduces weeds in beds.
  • Less toxic products like soaps, horticultural oils, and plant-based insecticides that work for many problems are now available – see Grow Smart Grow Safe below.
  • Beneficial insects that prey on problem bugs are available for sale, or you can attract these “good bugs” by planting a variety of plants that provide pollen and nectar all year.

Use chemical pesticides as the last resort

If you must use a chemical pesticide, use the least toxic product, and spot apply it – don’t spread it all over the yard to kill a few weeds or bugs. It may be best to have a professional who has all the protective gear do the application, but don’t use services that spread chemicals over the whole yard or spray on a calendar schedule. You want to apply pesticides only when and where you really have a problem. Follow label instructions exactly – more is not better. And be sure to keep children and pets out of application areas.

Replace problem plants with pest-resistant ones

If a plant, even a tree, has insect pest or disease problems every year, it’s time to replace it with a more pest-resistant, site-adapted variety or another type of plant that doesn’t have these problems.

Learn more

Related links

Links to other sites

Public Utilities

Andrew Lee, General Manager and CEO
Address: 700 5th Avenue, Suite 4900, Seattle, WA, 98104
Mailing Address: PO Box 34018, Seattle, WA, 98124-5177
Phone: (206) 684-3000

Newsletter Updates


Sign up for the latest updates from Public Utilities

Seattle Public Utilities (SPU) is comprised of three major direct-service providing utilities: the Water Utility, the Drainage and Wastewater Utility, and the Solid Waste Utility.