Weeds are much of the work in gardening. Yet with proper methods, weed control can be reduced to a fraction of the work that some of us
endure (or ignore).
Different weeds and situations call for various controls. Common places for us to fight them are gardens and landscape beds, lawns, and wild areas.
There are two main approaches to beds – exposed soil, and complete barrier mulches. Each has their purpose.
If the soil is left exposed, the area can be gardened easily if well prepared. The initial work may be the tough part. If the soil is native and not prepped it is probably hard and weedy. Spray the weeds (see below), and then amend the soil liberally with coarse compost and drainage (like sand or smooth pea gravel).
Well prepared soil is such a dramatic work saver, yet it is so common to find plantings in plain old dirt. It’s night and day, folks.
Barrier methods mostly include landscape fabric and a thick layer of mulch. The mulch is often a chipped or shredded wood. This wood is different than wood-based soil amendments. Mulches such as shredded cedar and redwood, bark nuggets, or aspen chips are very hard to dig through if mixed into soil. They are meant to be used as a blanket, not a mix. Most of the mulch woods break down very slowly compared to others. I once dug up fifteen year old intact bark nuggets that had been used as drainage at the bottom of a raised six by six planter.
Fabric and mulch beds form a complete barrier to weeds, but are suited to beds that are not going to be continually gardened. It’s still a good idea to kill out existing weeds to eliminate those types that might work through planting holes for desired plants.
Like it or not, the solution for many weeds in many places is to spray. Some weeds can be killed by cultivation, yet pests like Canada thistle can only be eliminated by spraying. Not all herbicides have serious toxic potential like some others. The glyphosate-based broad spectrum sprays such as Roundup and Kleenup have minimal impact on the environment.
Remember, broad spectrum herbicides kill grasses and broad-leaf weeds, so don’t use Roundup on your lawn. For lawn Use “broadleaf only” weed killers. There are also excellent grass-only products on the market to get rid of grass in your flowers. Look for the ingredient, “fluazifop”. It works.
These are all post-emergent herbicides. Pre-emergents are a topic for another day.
If you get ahead of weeds, stay ahead of them. Weeds and their roots are much easier to control when small.
Some flowers are weeds, even legally. We see Oxeye daisy all over, but it is not native (although wild), not very beneficial, and it is aggressive in the garden. It is also considered a no-no under the Colorado Weed Act. Avoid all “flowers” that are illegal weeds, such as Dame’s Rocket, and Purple loosestrife. If you like white daisies, use Shastas instead. They’re surprisingly tough, and not environmentally hostile like Oxeyes.
Open areas for a wildflower seeding are much the same. The important thing in all cases is to get rid of the weeds. This can mean more than one spraying. It’s worth the wait. In all situations, read the label for the recommended planting or seeding wait interval.
I can’t stress enough the value of building a good workable soil. The work saved will make a difference in your whole approach and result.