Linn County Master Gardener
OSU Linn County Master Gardener
THE WEEDS ARE BACK! With a vengeance, and with offspring, relatives and friends! The annual spring weed war is on!
Some zombie weeds have come back from roots we thought we killed last year. Some little weedlings have sprouted from seeds that have laid dormant from years past.
Some new weeds have floated in on the wind or dropped from the birds. The almost non-destructible pink-flowered wild geranium that blew around in the wildfire wind is everywhere.
Why do we get rid of weeds? They compete with desirable plants. They reduce aesthetic enjoyment of landscape areas.
Why do we all have weeds? As plants spread around the earth for agriculture and home horticulture unwanted seeds come with the imported plants and plant-eating animals.
Plants that might be valued or ignored in their native habitat become aggressive invaders in new locations that might suit them better. They grow quickly to capture sunlight, water, space and
nutrients.
Nature abhors a vacuum, and bare ground, so weeds rapidly fill voids in bare soil. Weeds generally germinate easily and abundantly, some releasing thousands of seeds per flower.
Weed seeds are usually long-lived, lying dormant for years – dandelion six years, thistle 20 years, blackberry 25 years, lambsquarters and purslane 40 years. Common weeds are adaptable to a wide variety of soil types and climates.
When it’s raining we can sit inside and look up weed identification and controls in the 612-page Pacific Northwest Weed Management Handbook published annually by Oregon State University. One can order the book for $80 or search within it for free online at .
There are dozens of other OSU publications focusing on specific weeds or plants affected by them. Or, we can just look out the window, scowl and make decisions about where to start getting the unwanted plants under control before they totally take over.
It doesn’t always matter if we name the weed when it is growing where we don’t want it. We just want to get it out of sight before it goes to seed or spreads.
First priority is eliminating bloomers, especially those prolific common yellow-flowering weeds. They are usually the largest weeds also, so right away the area can look better when they are in the bucket.
If the area still looks “weedy” even if you take off your glasses, make the second round of weed removal those that are spreading or likely to bloom if you leave them, like grass in plant beds.
To thwart tiny seedlings just rough up the soil or mulch and expose their tiny roots to dehydrate in the air. A new three-inch layer of mulch will block light and delay new sprouts.
Sprouted seedlings of valued plants can be dug up and moved to a new home.
Finally, hot compost the conquered weeds or send them to grow in the landfill. Chemicals should be used as a last resort, following label instructions carefully.
We can sharpen our tools to make the job easier. Hoes allow us to work in a standing position. There are many shapes available for the business end.
A scuffle hoe is knife-bladed and can be pushed or pulled, working best with young shallow-rooted weeds.
A pointy-tipped hoe can dig a hole down to cut a root and pull the weed’s crown up.
A flat-bladed hoe can scrape or dig, best used for shallow-rooted weeds.
To make a long-handled hoe more comfortable slip some pipe insulation foam over it.
Knives are often used to cut the roots below the surface and make it easier to pull established weeds. There are expensive hori-hori garden knives, but a kitchen knife can work as well.
A simple forked-tipped weeding hand tool can stab and sever roots too.
Rototillers disturb soil, kill worms and microbes, and bring dormant weed seeds up to find light. A small electric tiller can be useful to loosen the surface of damp weed-infested soil in a large area so it can be raked, but a hoe may still finish the job better.
Flame weeders work well on annual weeds (as in cracks of concrete) but are less effective on perennial plants. Open flames should be used carefully and safely in the yard and near wood.
Weed management has multiple objectives: Prevent bringing in new weeds in soil or container plants. Discourage weeds so they can’t compete with desired plants. Stop weeds from going to seed, gradually reducing the weed seed population already in the soil. Weed early, thoroughly and often.
