Mulched garden. Photo by F.D. Richards (Flickr).

Manage Weeds Naturally

You can grow a healthy, attractive landscape without using chemical weed killers. Herbicides (weed killers) can damage soil and plant health, poison pollinators and other wildlife, and harm our pets, kids and neighbors. Rainwater runoff carries these harmful chemicals through storm drains into local creeks harming salmon and other aquatic life. We can protect the health of families, wildlife and waterways by following these five steps of natural weed management:

Bee on dandelion near lawn daisies

It’s unrealistic to expect a perfectly weed-free yard. Decide which weeds you can tolerate. Then target the problem weeds. The goal is to manage weeds, not eradicate all of them. Also, consider that certain unharmful weeds can add beauty, provide habitat for wildlife, filter stormwater runoff, and feed pollinators.

“Weeds are flowers too, once you get to know them.”
– Eeyore, from Disney’s Winnie the Pooh

Figure out what you have, then learn how it spreads to find out the best strategy to control it. Prioritize managing any weeds that are invasive or noxious. Use a weed identification guide or ask an expert!

  • Identify your weeds with a photo ID guide.
  • If it’s on the local noxious weed list, you may be required by the state to manage it in order to prevent harm to crops, livestock, humans, waterways, habitats, and recreation areas.
  • Call an expert for help! Local Master Gardeners at WSU’s Plant Clinic can help, as can our regional Garden Hotline. They are great resources for helping identify weeds and giving simple advice on how to control a specific weed.
Three photos of weeds side by side. Weed on left - creeping buttercup, a weed with deeply lobed leaves and small yellow flowers with five petals. Weed in center - fig buttercup, also known as lesser celandine, a weed with round-ish leaves and small yellow flowers. Weed on right - herb robert, a weed with deeply lobed leaves and small purple flowers with five petals
Creeping buttercup (left) has yellow flowers that can be confused with fig buttercup (center) and leaves that can be confused with herb Robert (right). It’s helpful to take a photo of the plant that you can reference as you try to identify it. In the photo, show as many of its parts as you can, including the root, and take note of its size and location (sun, shade, soggy soil, etc.).

Don’t give weeds a chance. Weed seeds love bare soil and sunlight. Cover bare soil. Shade weeds out. Prevent their flowers from going to seed by pulling, mowing, or weed whacking before they can spread seeds. Find weed-specific management tips in our Common Weeds Booklet (PDF).

Mowing

This video explains the benefits of letting grass grow longer (2-3″) and leaving cuttings on the lawn.

Mulching

Wood chip mulch spread around landscape plants
Spreading a thick layer of mulch around landscape plants is one of the best ways to prevent weeds from growing.

Planting

  • Shade out weeds with more plants. Plant a ground cover or fill in gaps with more plants.
  • Water Wisely. Use drip irrigation where necessary in edible gardens and landscape beds to only water the plants you want, rather than sprinkling over a large area where weeds will also be watered.

Lake Whatcom Watershed Guidance

* Lake Whatcom watershed residents: Recommendations vary slightly from the list above to protect the lake from phosphorous runoff. Learn more.

Once you’ve identified your problem weed, pick your strategy. For some weeds, you can simply leave them lying where you pulled them, and the sun will dry them out. For others, you’ll need to kill the tops a few times in a row to exhaust the energy reserves in their roots. With certain weeds, it’s important to remove the whole root system. For some, it’s no problem to throw them into a well-functioning compost pile (get composting tips from WSU Extension), but others will always need to be put in the curbside yard waste bin. Many weed fact sheets in the plant ID guides above will include tips for manual control.

  • Ask an expert if you’re not sure of the best strategy. Local Master Gardeners at WSU’s Plant Clinic can help, as well as our regional Garden Hotline.
  • Use weeding tools that work for you. Ask your local garden center staff for tips.
Bottom of a long-handled weed puller being pushed into the ground on the center of a dandelion
Use long-handled weed pullers for weeds with a tap root (long, central root) like dandelions and thistles.
Bindweed vine with white flowers
Some weeds, such as bindweed (i.e., morning glory), must be removed completely, including as much of the root as possible, otherwise they will regrow from tiny root fragments. These should be put in a curbside yard waste bin, never in a home compost.
Single weed, a hairy bittercress with tiny white flowers
Many weeds, like bittercress (i.e., shotweed), can be hoed and left to dry out in the sun without having to pick them up. Photo by Melissa McMasters.
Flame weeder burning weeds between pavers
Weed burners can be used to carefully kill weeds in gravel and pavement cracks. Two or three passes over a few days will eventually exhaust a weed’s energy reserves in its roots.
  • If you’re working near or in a waterway, wetland, steep slope, forested area, or where runoff could flow to Lake Whatcom, you may need to take extra care about when and where you are removing vegetation. If you have any questions about whether this applies to you, City staff are always happy to help. Email askpw@cob.org or call Public Works at 360-778-7700.
  • If you plan to remove vegetation in public areas or near property lines, you may need permission from your neighbors or the City. This is especially important if you plan to replace the weeds with anything other than landscaping. Please contact our Permit Center if you are planning to do work near property lines or on public property.

If a weed problem persists, use the least toxic solution.

  • Less toxic products kill many weeds if used properly.
  • Look at the lowest risk, minimum hazard products ranked in the Grow Smart Grow Safe guide. Here, lawn and garden products are ranked based on hazards to humans, pets, wildlife, and aquatic life, and potential for water pollution.
  • If you must use a chemical herbicide, use the least toxic product. Check the Grow Smart Grow Safe guide for the lowest risk product.
  • Avoid weed and feed. These products contain pesticides.
  • Spot apply the treatment – don’t spread it all over the yard to kill a few weeds. Target the specific problem weeds.
  • Spray in the evening to reduce impact on pollinating insects.
  • Spray when it’s dry. Don’t spray right before irrigating or when rain or wind are expected.
  • Follow label instructions exactly – more is not better. Wear protective gear. Herbicides should not be sprayed within 60 feet of water bodies and creeks.
  • Consider hiring a professional. 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.
  • Keep safe. Plan ahead on how you will keep children and pets out of application areas.
Bee on cherry blossoms
If you must use a chemical herbicide (weed killer), protect bees and other pollinating insects by doing carefully targeted spraying late in the evening.

Additional Resources

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