Too much phosphorus carried in by polluted runoff is causing problems in Snohomish County lakes. Lawns and yards can be a big source of phosphorus from a variety of sources like fertilizers, pet waste and bare soils, which are already rich in phosphorus.
The solution: Be LakeWise for your lawns and yards
You make a difference. By making a few simple changes in your lawn and yard practices, you can improve water quality and get LakeWise Certified. Just follow the Clear Choices Checklist for Lawns and Yards.
One simple change you can make: Use a mulching mower and leave grass clippings on the lawn.
Unchecked surface water runoff picks up phosphorus as it flows to the lake below.
If you use fertilizers, make sure they do not contain phosphorus.
By making these small changes you can protect your lake and the health of family:
1. Properly dispose of dog poo
Scoop it, bag it, throw it in the trash
This isn't Las Vegas. What your dog does in your yard doesn’t stay in your yard.
More than 157,000 dogs live in Snohomish County. Every day, they produce the same amount of untreated waste as 40,000 people -- the population of Edmonds.
Pet waste contains harmful bacteria and parasites that can be transmitted to people, pets and wildlife. Things like fecal coliform bacteria, salmonella, roundworms and E. coli can persist in your yard for weeks and be brought into your home on paws. When it rains, the pathogens and phosphorus are washed into our lakes and streams where we swim, fish and play.
As a pet owner, what can you do?
Scoop the poop, bag it, put it in the trash. That's the safest way to ditch the poop.
Burying the poop isn’t good since bacteria can survive for years in the soil and may contaminate nearby wells.
Composting poop at home doesn’t work since household bins don’t get hot enough to kill hazardous bacteria.
If you have horses or livestock, consult with the Snohomish Conservation District for the best way to handle manure and prevent it from polluting your local water.
Visit our Pet Waste page for additional resources and to learn more about preventing pollution from poop.
2. Attend a natural lawn care workshop
Have a beautiful yard the natural way
Do you love lush green lawns but don’t like using so many pesticides, fertilizers and extra water?
By switching to natural lawn care techniques, you can have a yard that’s beautiful, easier to maintain and safe and healthy for your family, pets and lake.
LakeWise natural lawn care workshops are led by professional lawn care experts where you will learn:
Tools to have a healthy lawn without extra pesticides and chemicals.
Tips to deal with moss, moles and other pests the natural way.
Workshops are held in the spring and fall. Check the side panel for upcoming dates and to register.
Want to learn more about natural yard care?
Click to download the “Natural Lawn Care” (PDF) guide or visit our Natural Yard Care page for additional resources on soils, plants, watering and composting. The Grow Smart, Grow Safe website is also a great resource for learning about getting your yard to a natural state.
3. Skip lawn fertilizer or go phosphorus-free
You don't need to add phosphorus to have a healthy lawn
While it’s best to skip fertilizer altogether to create a healthy lawn, the next best option is to choose phosphorus-free fertilizers. The good news for lawns and lakes in Snohomish County, is that our native soils are naturally rich in phosphorus. Established lawns don’t need a phosphorus boost to look and grow great.
Be sure your fertilizer is phosphorus-free by looking for a “zero in the middle” of the bag’s label. Fertilizer bags will have three numbers that list the content of nitrogen, phosphorus, and potassium as a percentage of the bag's volume.
Over the past few years, most producers have removed phosphorus from lawn fertilizer, but be careful if you’re buying pasture fertilizers and plant feed. Some still contain phosphorus.
Whatever product you use, follow the label instructions and don’t apply more fertilizer than recommended. Clean up any extra fertilizer.
The Snohomish Conservation District offers guidance to build soil health. Their "Know Your Soils" booklet provides an introduction to soil testing and using amendments to build healthy soil. View it online or request a paper copy on their website.
4. Stabilize your slopes
Cover bare soil areas and fix erosion problems
Keep our phosphorus-rich soils covered and avoid erosion.
Bare soils and dirt patches are pretty common in our yards. While seemingly harmless, exposed soils are easily carried away by rainfall. The extra dirt means extra phosphorus and more algae in your lake. The problem is especially bad on eroding hillsides.
Rainfall and surface water runoff will pick up phosphorus in the soil and deposit it in your lake.
Unchecked erosion can cause serious damage to your landscape and harms water quality.
Runoff water flows across bare soil and carries phosphorus into the lake below.
For bare soil areas in your yard, cover with mulch or plants:
Mulch - Apply a layer of suitable mulch and reapply in subsequent years. See “Growing Healthy Soils” for mulch recommendations.
Plants - For a long-term solution, plant the area with evergreen groundcover or other plants suitable to the site conditions. Space plants so that at maturity they cover the soil so you don’t need to mulch.
Live stakes are branches cut from woody shrubs and trees that root quickly in wet soil.
Straw spread over bare soil will minimize potential erosion.
Tubes of straw, called wattles, can be staked into hillsides to stabilize soils.
Evergreen ground covers such as kinnikinnick will help stabilize slopes and limit erosion.
Use wood chips to cover bare soils. Wood chips also act as a mulch for plants and reduce the need for irrigation.
For sloped areas with erosion problems:
Plant the area with woody plants that will establish an underground network of roots to hold soils in place. This can be done in conjunction with temporary erosion controls.
Temporarily stabilize the area by covering with straw, fiber erosion control blankets or fiber rolls (straw wattles).
Sediment and erosion control materials are available locally from:
If the erosion is significant and makes planting difficult, try these techniques:
Plant “live stakes” into the hillside and cover the surrounding area with straw or fiber mats.
Live stakes are a cutting of a woody shrub that roots quickly in wet soils. Plants include salmonberry, snowberry, red twig dogwood, willow, cottonwood and nine bark.
If you have had a LakeWise visit, Snohomish County may be able to provide free live stakes. Otherwise, check online for live stakes sellers.
If you have significant erosion problems that are undermining the integrity of your property, you should consult with a geotechnical engineer or other erosion professional.
Natural Yard Care resources
These additional brochures and resources will help you get your yard into a natural state.
Choosing the Right Plants for a Beautiful, Trouble-Free Garden
