Lawns and Yards

Here’s the problem:

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.

By making these small changes you can protect your lake and the health of family. Find out more about each below:

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What to do with 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.

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 on the links to download the “Natural Lawn Care” guide or visit our Natural Yard Care page for additional resources on soils, plants, watering and composting.

You can have a naturally beautiful yard

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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. Over the past few years, most producers have removed phosphorus from lawn fertilizer, but be careful if you’re buying pasture fertilizers. 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’s Healthy Soils Program offers soil testing and consultations to improve soil health. They’ll even help you throw a neighborhood compost and lawn aeration party. Follow the link to learn more. 

Read the label

Fertilizer bags will have three numbers that list the content of nitrogen, phosphorus and potassium as a percentage of the bag's volume. Your yard won't benefit from any fertilizer that contains phosphorus. Snohomish County's native soils already have plenty of it.

  • The first number is for nitrogen (N).
  • The second number is for phosphorus (P).
  • The third number is for potassium (K).

Cover your bare soils

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How to stabilize your slopes

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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.

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. 
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: 
  • ACF West, 15540 Woodinville-Redmond Road, Bldg. A-400, Woodinville. 425-415-6115;
  • Cenex Co-op, 2901 State St., Everett. 425-259-5571
  • H.B. Jaeger Co., 1830 16th St., Snohomish. 360-568-5958;
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.
  • Build a retaining wall. Snohomish County Assistance Bulletin #40 provides retaining wall information, including permit information.
  • 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.
Divert runoff from driveways, roofs and parking areas into stable vegetated areas

Do you know what’s in your runoff and where the water goes?

Driveways, parking areas, roofs and other hard surfaces contribute phosphorus since they accumulate dirt and dust. When it rains, runoff picks up the dirt along with leaked oils and fluids and trace heavy metals from vehicle tires and brakes. Piping this water right to a lake, stream or ditch doesn’t let the water soak into the ground where nature can clean it.

1. Find out where your runoff goes

Homes built before the 1990s often pipe runoff to the nearest ditch, stream or lake. Take a look at your downspouts and driveway drains and see where they go. Look for pipes that go to the lake or ditch. If your house was built after the 1990s, your runoff likely goes to an underground infiltration system.

2. If your runoff is piped into the lake, consider redirecting the flow

  • Divert downspout flow by using extensions or flexible pipe to send runoff into landscaped areas at least 10 feet away from your foundation. 
  • Shorten the drainage pipe and add deep-rooted plants between the new outlet and shore to filter pollutants before they reach the lake.
  • Divert runoff into an infiltration trench or dry well.
  • For driveways, add cross berms or slot drains to direct surface runoff into stable, vegetated areas or an infiltration trench. 
  • For downspouts that aren’t connected to drain pipes, use splash blocks under the outlet to slow the water and spread it out.
When diverting runoff, do not direct it:

  • Within 10 feet of structures
  • Near septic system drainfields (at least 50 feet uphill or 10 feet downhill)
  • Within 100 feet of drinking water wells
  • Near property lines
  • Near the edges of steep slopes or bluffs
If you plan to dig up and disconnect a drainage pipe, call 811 first to have all underground utilities located and marked. 

3. Not sure where to start or need advice? Have a FREE consultation with a county drainage expert

Snohomish County’s drainage technicians work with landowners who are having problems with water on their property or want to better infiltrate it. They can help you locate your runoff system and help you find workable solutions specific to your property. To schedule a visit, call 425-388-6467 or visit and go to the drainage problem link to fill out a request. Mention LakeWise so they can better help you.