Winning the War Against Weeds

We all know the feeling of stepping outside to admire our flower or vegetable beds only to be shocked by an invasion of unsightly weeds.

So it is time for battle gardeners!

Unfortunately, weeds will always be a part of our lives to some degree, but there are several great ways to keep them at a minimum with just a bit of effort. Read on for some of the best physical controls for weeds, as well as preventative measures and possible organic and chemical treatments.

Let’s start with the first line of defense; weed often! Try to get them when they are small and before they go to seed. Larger/older weeds have more stored energy in their roots which make it easier for them to survive the weeding process. And depending on the weed, they may produce hundreds or even thousands of new seeds per weed if left unattended. Not only that, but seeds can live for 10-50 years or longer in the soil.

The picture of bittercress (Cardamine hirsute), aka shotweed, is very common in Ocean Shores and throughout Western Washington. Even though it is small in stature, it can produce hundreds of seeds per plant and can send them 6 feet in every direction!

The best option when dealing with most weeds is to hand pull them, roots and all. Your soil will get a bonus with some extra aeration, too. Horsetail is an exception. In most cases trying to dig up horsetail will make the plant spread more vigorously. Just cut horsetail at the ground level to weaken it.

You can also use a hoe on small weeds and let them dry in the sun. This is best done in the morning on a warm dry day. Weeds left on wet soil may re-root. Be careful to not bring new seeds to the surface. Hand weeding is also best in the morning on a sunny day to provide maximum stress on any parts of the weeds left behind.

It is a good idea to get to know your enemy. Take time to learn what weeds you have, how/when they spread, and ways to get rid of each of them (i.e. are they annual or perennial, do they spread by seeds or rhizomes, etc.). A plant ID app is a great asset when you need to identify a weed and many of these apps are free.

If you have a rototiller, it may work on annual weeds but is not advisable for perennial weeds as new weeds can sprout from the chopped fragments. Rototilling may also bring hardy weed seeds to the surface.

Whenever possible, consider preventative measures to keep weeds from sprouting.

• Use about 2” of bark mulch to smother weeds. First cover the ground with cardboard or several layers of newspaper, then cover with mulch.
• Grow landscape plants close together to block sunlight making it difficult for weed seeds to germinate.
• Use steppingstones, large rock gravel, or river rock to cover pathways and areas not planted.
• Fill cracks in driveways or patios with asphalt or masonry caulk after weeding.
• Use low maintenance groundcover plants such as sedum to block out weeds and add color and texture to your landscape.
• Keep your desired plants and lawns as healthy as possible so they out-compete the weeds.
• Cover garden beds with straw in the fall to help keep new seeds from taking root. Remove the straw when you are ready to plant in the spring.
• Mow tall weeds before they go to seed in large areas such as lawns and roadsides.

For stubborn weeds, herbicides can be an option. It is always best to try non-chemical methods first if possible, and always use herbicides according to directions on the label. As mentioned before, it is important to get to know and understand your weeds. Not every herbicide is effective on every weed. Using an ineffective weed killer not only is bad for the environment it is also a waste of your time and money. So, try to understand the herbicides available as well as the weeds that they treat.

Here are some important considerations when using either organic or chemical herbicides.

• Consider more selective herbicides (i.e. grass killer) rather than non-selective ones like glyphosate that can potentially harm valuable landscape plants along with the weeds.
• Home remedies (such as vinegar, salt, and boiling water) do not always work and can harm the natural balance and ecosystem of the soil.
• If using an herbicide spray on perennial weeds, be certain that it will translocate to the root, not just the leaves. Otherwise, the weed will grow back.
• Pre-emergent granules can be very effective in keeping seeds in the soil from germinating but will not kill existing weeds. Use these in spring before new weeds sprout.
• It is best to use all herbicides on a calm day to keep the spray or granules from going astray.
• Foliar sprays should be done when plants are dry. Don’t water (and no rain) for at least 6 hours in most cases.
• Avoid using chemicals near waterways. Stay at least 10 feet from the water.

As you are combating weeds, consider multiple methods of weed control for tough areas. This can involve several non-chemical methods such as hand weeding, planting plants close together, and mulching, and then using an herbicide to spot treat some more stubborn weeds if needed. Weed control takes vigilance and may take a couple of years before you feel you have them under control.

And finally, it is ok to tolerate some weeds…don’t let them control you. Many “weeds” are also considered wildflowers and attract pollinators! And instead of trying to totally eradicate weeds, work on minimizing them.

For more information contact us at info@gardenbytheseaoceanshores.org.

This article was originally published in the May 2024 issue of the Ocean Observer.