Planting Edmonds: Garden weed management

Planting Edmonds is a monthly column written by and for local gardeners.

As this winter began to loosen its cold and clammy grip, I ventured into my garden to behold the wonders I had been dreaming about while wrapped in wool watching the gray mist wafting through the trees.

I peeked out of my front door like Punxsutawney Phil on Groundhog’s Day and gazed into my garden. To my delight, I could see in the distance a healthy green living plant gracing my otherwise-barren garden bed.

I stepped into the wet grass for a closer look at what hardy beauty was making its debut. I bent over for a closer look and there it was …. Stinky Bob (a.k.a. “Herb-Robert,” Geranium robertianum) – a weed! Upon further investigation of my garden, just about every low-growing herbaceous plant in my garden was a weed too.

Stinky Bob in my late winter garden.

What are these hardy occupants of our gardens? How do we control them? How do we get rid of them? Read on – we will get “into the weeds” about home garden weed management.

A helpful definition of a weed is: a plant growing where it is not welcome. That is simple and easy to apply to your garden. Do you want that plant? If not, it is a weed (at least to you). In my first peek in my garden, the Stinky Bob was clearly a weed.

Other cases are more in the eye of the beholder. For example, when I went to Hickman Park earlier this year, I saw on the grass a lovely patch of flowering dandelions and daisies.

If you want your lawn to be a monoculture of manicured grass, those flowers are weeds. Likewise, if you have grass growing in your flower garden bed, it could be designated a weed. It’s all up to you.

Dandelions and daisies at Hickman Park.

Plants purposefully added to your garden for their horticultural attributes — I am going to call them “unweeds” — can turn into weeds. Sometimes, over time, unweeds can spread beyond their planned boundaries and start crowding out other unweeds. They now become unwanted, thus weeds.

For example, my wife bought on a whim a native plant called Pearly Everlasting (Anaphalis margaritacea). She loved its pearly-white flowers. It thrived and was a nice addition to our garden – at first.

Then (Jaws theme music plays in the background) it kept on thriving well beyond our intentions for its contribution to our garden. It spreads aggressively via runners. Now, it’s a weed — to us — and we hope there isn’t a more sinister reason it has the word “everlasting” in its name.

Pearly Everlasting in our backyard. It started as a welcome native.

An infamous example of the unweed-to-weed transition is kudzu (Pueraria montana). This vine was brought to the southern U.S. from Japan and southeastern China in 1876 for use as an ornamental. Later, in the 1930s through the 1950s, it was touted for its utility in erosion control.

Kudzu was great at rapidly covering barren hillsides next to highways; but … it didn’t stop there (Jaws theme music reprisal, but louder). After fulfilling its intended role, it kept on growing … and growing …  and growing!

Into the woods and over trees and beyond it grew at one foot per day for mature plants. Kudzu’s days as an unweed are over — it is now definitely a much-reviled weed.

Kudzu spreads aggressively. (Photo by

We urban area gardeners have several choices of ways to manage weeds in our gardens. One option is to do absolutely nothing. Let the weeds grow untethered from homeowner intervention.

All you do to implement this weed elimination strategy is simply declare all plants in our yards as “wanted” and — voila! — they are thus no longer weeds. Problem solved, right?

Some argue that this is the best approach for current times. Let our land revert to its pristine form from the days before an influx of non-native Americans arrived in numbers. This should be good for all the bees, birds and earthworms; the result will be a step toward the mid-1800s lush forest that was here. We do less work, and it is better for the planet.

A perfect plan, right? Not so fast.

There are some issues with the “back to nature” weed management plan. Our neighbors might not appreciate our noble quest for a better planet and interpret your brilliant win/win plan as an unsightly nuisance. Even more problematic is the type of plants that might populate (infest, rather) our yards — and our neighbors’ yards.

The house I purchased in Edmonds six years ago had a yard that was allowed to “run free” for quite a while before we moved in. I left many plants alone as I was learning about Pacific Northwest gardens.

One of these was an interesting, vigorous plant in the front bed. I let it express its intrinsic beauty until my wife looked it up and identified it as…poison hemlock (Conium maculatum)! The whole plant is toxic to humans and animals. Egads! It’s a weed. Out it went.

Poison Hemlock at Richmond Beach Saltwater Park.

Another conspicuous plant on our property was a handsome evergreen shrub that seemed to be doing very well so I left it alone until … I looked it up. It was spurge laurel (Daphne laureola), also poisonous to humans and a designated noxious weed. I am STILL trying to get this one out of my yard.

Laurel spurge from my yard.

These personal examples show that some of the plants that will populate our well-meaning back-to-nature gardens can be unsightly, possibly poisonous and may be officially noxious.

Our Edmonds area landscape is no longer the pristine old-growth forest of yore. We have changed it – dramatically – introducing a host of plants that are new to this area.

Our self-declared unweed zone will be enticing to newly arrived bullies like Himalayan blackberry (Rubus bifrons), English ivy (Hedera halix) and a host of aggressive and invasive plants.

What we can do is work with the current urban (disturbed and altered) environment that we inhabit by taking a more moderate step toward “back to nature” in tune with today’s sensibilities.

Choose native plants that are appropriate for your soil and exposure. Remove invasives and noxious weeds. Reduce lawn area or even replace it with a managed meadow of plants beneficial to the native pollinators and birds.

Not everyone is ready for a wild look for their garden. I’m not there yet either. Another approach – and this is my favorite – is to design and manage your garden to limit weed growth.

Since many weeds thrive in open, sunny disturbed ground, cover that bare ground with shrubs, perennials and groundcovers. The weeds simply won’t like it. This is a longer-term solution, but the endgame is a lush garden free of weeds.

That is what we are trying to do in our garden. We have patches of bare garden beds where we have removed unsightly (and poisonous even) shrubs and plants. I am working toward covering all of it with a lush canopy of unweeds.

This process is called canopy closure — the vegetation closes off open soil. It is a well-recognized weed management strategy in modern agriculture.

Row spacing of crops such as soybeans is selected to give the soybean plants enough room to thrive and achieve canopy closure that will protect yield from competing weed pressure. This strategy applies just as well to the home gardener in Edmonds.

Soybean canopy closure. (Photo courtesy of North Dakota State University)
Not much room for the weeds in this part of my Edmonds garden — good canopy closure!

Until the canopy completely closes, we can add mulch to bare soil to suppress weed growth. Weeds typically need sunlight and bear small seeds at a shallow depth. About a 4-inch layer of coarse wood chip mulch will prevent weed growth while helping our garden soil ecosystem. Nature’s natural mulch of dried leaves helps too. Leave them on the garden surface.

The power of mulch. I added mulch (bottom half of photo), and my neighbor (top half of photo) didn’t.

Okay, we are working to get complete canopy closure, but it will take time. We’ve added a good layer of organic mulch to the bare ground to suppress the weeds until the plant canopy catches up. What about the weeds there now?

There are many ways to kill weeds. We can remove them by hand or hand tool, rototill them up, cut them at soil level with a weed whacker, burn them, starve them from light with an opaque covering (thick mulch, cardboard, etc.), scald them with hot water or kill them with household chemicals (vinegar, for example) or manufactured synthetic chemicals (i.e. herbicides). For the sake of brevity, I am only going to discuss manual and chemical weed removal.

Weeds are smart, persistent, pervasive and adaptive. They are smarter, tougher and more prolific than our precious unweeds in the garden. Weeds can produce huge numbers of seeds – sometimes millions per plant – and these can persist a long time in the soil, waiting for the right conditions to germinate. Get rid of them before they go to seed.

Some weeds have deep roots, like dandelion (Taraxacum officinale). We need to get the root — all the root — to prevent this weed and others from coming back. Our strategy then: Get rid of weeds while protecting the unweeds.

Hand removal of weeds in the garden is a great option for the home gardener. We can plunk ourselves down into our garden beds with our favorite tool (a Hori Hori knife is mine) and meticulously dig and pull all the weeds, roots and all.

This sounds tedious, but many a gardener will tell you about the Zen-like tranquility of getting down and dirty in our gardens to remove weeds. Time slows down, nature surrounds you, insects and worms appear when we get IN the garden. We also get close-up and intimate with our unweeds. We notice features about them that you can’t see from the lawn or driveway.

Myself, I don’t listen to music or podcasts while weeding; I listen to the world around me. While sitting “in the weeds” I have watched a pileated woodpecker working the Douglas firs next door and observed a Cooper’s hawk perched in the trees. And then there’s that earthy smell of soil, moist vegetation and, if you’re lucky, a wonderfully scented unweed nearby.

Removing Stinky Bob with my trusty Hori Hori knife.

Our values on home lawn and garden weed control have evolved over time. When I was a youngster growing up in Spokane, the ideal yard was highly manicured and weed-free.

I remember tanker trucks proudly labeled “ChemLawn” parking at my neighbor’s house and a person pulling a hose from the back and flippantly spraying high volumes of herbicide (weed killer) on the lawn (and the other plants as well).

The goal was no weeds — not a one, zippo — on the lawn. Things have changed for the better. We have become more tolerant of a few weeds in our grass and less tolerant of adding herbicides.

We also weeded with a spading fork, turning over all the soil and removing the weeds. Today, we are starting to understand and appreciate the important soil ecosystem and try to avoid disturbing it. Targeted hand weeding allows you to preserve the unweeds and reduce the disruption of surrounding soil and its ecosystem.

For the urban homeowner, sometimes the use of a synthetic herbicide is a good option for weed control. We are all trying to limit our addition of novel chemicals into the environment. Not everyone is physically able to manually remove weeds in their gardens.

Sometimes the scope of the problem – a large newly disturbed bed – is too vast to tackle manually. Sometimes the gardener needs some extra help getting the weeds under control so they can then start using other weeding methods. Some people are extremely sensitive to poisonous weeds (allergies, for example).

In these cases, it is helpful to have a synthetic herbicide in your gardening toolkit. The days of ChemLawn tanker trucks spraying our lawn are over, but the prudent utilization of a synthetic herbicide when needed is sometimes a big help.

The objective with the use of any synthetic herbicide around our homes is to use only if necessary, use only the amount you need and follow the instructions on the label. Personal protective equipment will keep you safe, and proper disposal of unused product will keep the environment safe. Consult with your garden store expert before using a synthetic herbicide.

Whew! We’ve covered a lot of ground – hopefully with mulch and canopy closure! Weeds are an inevitable part of gardening. We are in control. We get to declare what is a weed. We get to choose from a variety of strategies to deal with them, from embracing them to snuffing them out.

Weeds are tough, sneaky and persistent; but with the right approach and due diligence, we can minimize their foothold in our gardens.

My poison hemlock is long gone. I am making progress on reducing insidious laurel spurge from my property. I am working hard to develop a garden that has a closed canopy.

In the meantime, I am relying on organic mulch. I am embracing the inner joy of hand-weeding where practical. Oh … and that Stinky Bob from February? I got it good with my Hori Hori knife! Happy weeding!

— By Joel Ream

Joel Ream grew up in Spokane and earned a Bachelor of Science in botany at the University of Washington and a Master’s in botany at Michigan State University. Joel spent 37 years as a plant biologist at Monsanto, using plant physiology, biochemistry, and analytics to increase the efficiency of crop production. He also worked on new weed control technologies, regulatory studies to support the safety of new products, greenhouse and field evaluation of new crop varieties, increasing the nutritional value of animal feed, and developing methods to measure grain composition. Joel retired to Edmonds in 2018.

  1. Could you please forward this to the parks department cause the weeds are getting out of control in the new planting medium on hwy 99.

  2. What a great article. When possible I am going to print and save it. Any future information will be greatly appreciated.

    An inspiration hit me this year and that is to cling to every sunny day like a life raft. To say to heck with vacuuming and dishes. They will wait. The gardening won’t.

    Many thanks

  3. When I moved to Seattle in February there were 21 straight days of rain. When it was sunny I heard the noise of many garden tools. I soon found out that when sun arrived the gardener got busy. Weeds love the sun and grow fast. So take to heart the advice to weed early and often. You will enjoy your garden much more.

  4. Great and informative article. Here’s my dilemma: my next door neighbor has allow what has been identified as Persian Laurel to grow right at the fence line. It is now a very tall tree – hanging over the fence and taking care of what sunlight I had for a bed there. This tree makes such a mess of old flower stems about a foot long and berries that germinate everywhere. I ask him to trim it back, but he ‘likes it’….What to do?

    1. I suspect what your neighbor has is a Portugal laurel, which is a real pest here. While not as ubiquitous as the English laurel, the Portugal laurel is happily growing in our wild areas due to its ability to reseed itself via bird droppings. It’s often said that you can prune off anything growing on your side of the fence (citation needed?), but I’d hope to get the concurrence of your neighbor for the sake of peace in the ‘hood. It won’t improve the sunlight but could help with the mess. Hire an ISA-certified arborist who knows the law.

  5. Loved this article. This year we did get a very early head start on the weeding. Now I can easily spot the little stinkers and get them quickly. I also this year tried the boiling water method for weed growing in between and out from under large ornamental rocks. It was several weeks ago and not one of those has dared to come back. I tried it on a couple of dandelions that like to grown in my paving stone cracks in the pebbles that separate those. It took two applications 3 days apart on those, but it worked. I listened to what our author said in the article and my gardens are pretty well covered but I purchased a few hardy to -20 perennials to add coverage. It’s pretty dense out there so I will need to use wet newspaper and some mulch in a few areas but that’s it. Spring is so my favorite season. Watching this overnight growth is so pleasant. The birds are very happy too. Hummingbirds all over I think they are nesting in the lichen and the very thick jasmine vines all along my fence line. Cosmos, Fushia Standard perennials for these fuchsias and Marigolds Coreopsis’s and Galiardi Camelia (about done on those and climbing hydrangea flowering is coming. and my 2 new Blueberry bushes are flowering… Yippie.

Leave a Reply

Your email address will not be published. Required fields are marked *

Real first and last names — as well as city of residence — are required for all commenters.
This is so we can verify your identity before approving your comment.

By commenting here you agree to abide by our Code of Conduct. Please read our code at the bottom of this page before commenting.