kcweeds

Spring Cleaning – Get into the Weeds

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Getting started
Tools & methods
Weed management strategies

Spring is the ideal time to control most weeds, here’s why:

Soft soils make it easier to get the whole root

Still time to stop weeds from making seeds

Plants are actively growing

These factors make it an ideal time for a lot of weed control methods. What is “best” will always depend on your specific circumstance, so as you read on, keep this in mind. But generally, the best practices go with the seasons and weather patterns and will vary based on the weed(s) you’re dealing with. 

For some guidance on what weeds are out at this time of year, check out our other most recent blog post about springtime weeds.

So with that…let us get into the weeds! 

Getting started

Scope your site

Break up into big areas based on the intended use of that space and its features, treat these as individual sites!  

  • Garden bed, landscaping under plants, monoculture of weeds, farmland, driveway, rock wall, etc. 
  • Note the plants you have growing in these spaces-weeds vs desirable vegetation.
    • This will help you use the right tools for the job and also give you reasonable sized projects as you go. 

General rules of (green) thumb:

  • Combining methods rather than using just one is much more effective 
  • You can weed anytime, but in the spring the ideal timing will be species dependent and starts as soon as you see new growth up until the plant is ready to make seeds (flowering). 
  • Consider the seeds and roots in your weed control – the bigger the roots, the more persistent you will need to be with regrowth. Similarly, the more seeds you have, the more likely you will need to control new growth. 
  • Prioritize work on your site by starting from the edges/least infested areas and moving inward 
  • Be patient and plan ahead! Plan for at least one pass of maintenance for each season in order to keep the weeds from coming back 

Tools & methods

Helpful hand tools

Hori Hori AKA a Japanese digging knife

Hand pruners/shears

Folding hand saw

Which tool for what?

Select a photo to make it bigger.

Manual Weed Control –

non-power tools

Left to right: Weed Wrench™ (aka uprooter), shovel, grub hoe (great for weeds on a slope), tarp.

Mechanical Weed Control – power tools

Left to right: brush cutter with tri-blade (great for mulching blackberry), flame weeder, mower, tiller.

Chemical Weed Control – herbicide

Left to right: backpack sprayer, hand sprayer, cut/dab method (concentrated herbicide on freshly cut starchy/woody stem, using a grout bottle here), EZ-ject injection with copper herbicide bullets for larger woody invasives.

Cultural Weed Control – alter plant’s environment so weeds struggle, & desirable plants can thrive (must combine with other methods)

Left to right: sheet mulching (papery layer then 12 in.+ mulch), tarping, aeration, planting desirable vegetation.

What if I don’t have any of these tools?

Don’t let that get in the way of managing your weeds!

Visit your local tool library in person or online first to see if they have what you need.

Tools for loan in King County, Washington:

Combining methods is key

A few springtime weed management strategies

Integrated Pest Management (IPM) – using a combination of the right methods throughout the seasons for the most effective long-term control.

There are endless ways to approach weed control. The methods below are just a few of those that we recommend specifically for springtime conditions. They are organized based on infestation size and location. Use your zoning from earlier to determine which situation is best for each zone.

For all methods listed below:

  • Plan to follow up and control new/re-growth throughout the season.
  • You can combine with planting/seeding. Be aware you will need to water the new planting regularly which also will be watering the remaining weed parts & seeds. If planning to use herbicide within the season, consider waiting to plant until fall.
  • Clean your equipment & gear, don’t be a vector for seeds!
  • Be mindful of soil disturbance – this can surface old weed seeds.
  • Disposal: flowering or seeding parts go in the garbage, the rest can go in the compost (compost does not get hot enough to kill seeds).

Small to medium infestations

Manual + sheet mulching

This method is great because you can do it all in one season rather than having to wait for regrowth before starting the second method.

  1. Dig out plants and their roots (can also just cut down, but note the more root that is left, the more regrowth you should anticipate) 
  2. Fill in any holes made during removal 
  3. Cover the infestation area + 2 ft on each side with cardboard 
  4. Top cardboard with 12 – 18 inches of mulch 

Medium to large infestations

Mechanical + other on regrowth later

The follow up method will depend on if you are comfortable using herbicide on your site. Break your site up into smaller sections based on natural or chosen boundaries. Start one section at a time.

  1. Mow, till, or burn target plant area before flowering begins 
  2. WAIT for substantial regrowth – plant dependent, 1 – 4 months 
  3. For smaller medium infests, can optionally sheet mulch during waiting period as described above for small infestations
  4. Once regrowth is established (multiple sets of full leaves) you can do one of the following: 
    1. Spray regrowth with the appropriate herbicide 
      • OR 
    2. Repeat initial mechanical method used

Complex/difficult spaces (rock walls, steep slopes)

Mechanical OR mechanical cutting + mulch (if reasonable) + other on regrowth later

In these areas it may be hard to access the root of the plant, or maybe even risky depending on the location. There are ways to get around this!

  1. Mow, till, or burn target plant area before flowering begins 
  2. WAIT for substantial regrowth – plant dependent, 1 – 4 months 
  3. For smaller medium infests, can optionally sheet mulch during waiting period as described above for small infestations
  4. Once regrowth is established (multiple sets of full leaves) you can do one of the following: 
    1. Spray regrowth with the appropriate herbicide 
      • OR 
    2. Repeat initial mechanical method used

Grassy areas

Manual, mechanical, OR selective herbicide + manual, mechanical, OR selective herbicide

Which method(s) you use will depend on your comfort with using herbicide, the size of your site, and the vegetation there (density and weeds vs. desirable plants).

  1. Start with one of the following: 
    1. Mow area before flowers appear in drier weather 
      • If your weed can spread vegetatively, make sure your mower has a bag attachment rather than the mulch setting 
    2. Dig out each plant & its root carefully in moister weather 
    3. Spot spray weeds with a selective herbicide (won’t kill grasses) 
  2. Follow with one or both of the following on any new/regrowth: 
    1. As soon as it appears 
      • Pull it! 
    2. Once regrowth has established (multiple sets of mature leaves) 
      • Re-mow the area 
      • Re-spot-spray the area 

Spring > summer (when it comes to weed control)

Weed management takes work, but the sooner we control our weeds, the less time and resources will need to be put towards their control. There will only be more weeds next year, unless you take action this spring. In a few months weed management will become less optimal as our days will grow long and hot, the soil dries out, and weeds bolt and flower (and thus make more seeds for you to manage next year). Spring is the time to pull your weeds and make space for native plants that depend on weed free natural areas, so let’s do it! 

For some guidance on what weeds are out at this time of year, check out our other most recent blog post about springtime weeds.

If you have any questions about how to approach weed management at your site, email our team at noxious.weeds@kingcounty.gov 

Happy weeding! 

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