Just as garden enthusiasts maintain their own opinions of favorite ornamental species, they all have a different idea of what the most objectionable weeds are. I could only mention a few in previous articles. Others include, but are not limited to, spotted spurge, bindweed, nut grass, foxtail grass, and blackberry.

Spotted spurge behaves much like portulaca by producing a profusion of seed very quickly. It grows just about anywhere that is exposed, including expansion joints in concrete pavement. They mostly die back within the next month or so, but can quickly return with warm weather in early spring.

Bindweed resembles and is actually often known as morning glory. It grows in exposed soil, but is more of problem in dense, hard soil from which the roots are not so easily removed. Those who have them in the garden now have left them too long, because they go to seed in autumn prior to winter dormancy. Not only are seed profuse, but they may germinate years after the main plant has been removed.

Blackberry is not as common among urban landscapes as the others, but the roots are nearly impossible to kill. One at my mother’s home that I started pulling and even dug out a few times since about 1976 is still alive! Blackberry is more common in the north and considered by some to be the state weed of Oregon.

Nut grass is also not as common as the others, nor as tolerant to adverse conditions. However, when it sets weed in well irrigated areas, it is nearly impossible to eradicate. Foxtail grass is somewhat easier to eradicate than most weeds unless it gets into lawns. If mowed, it will grow flat along with the lawn grasses and can be difficult to separate.

Unfortunately, space is too limited in this politically correct column for me to adequately discuss herbicides. Selection of herbicides should be determined by the weed to be eradicated. Although some are not specific, killing everything, others are used only for specific weeds. For example, ‘broadleaf’ contact herbicides may be used for dandelions in a lawn of grass. ‘Contact’ and ‘translocated’ herbicides are ‘post-emergent’ applied to existing weeds. ‘Pre-emergent’ herbicides kill weeds as they germinate.

Weeds may be pulled from near shallow rooted plants, but may be tilled or hoed in areas where surface roots are not a concern. Once eradicated, weeds may be more easily controlled if soil is not exposed to sunlight. Weeds do not easily recover if they are shaded by densely planted ornamentals, ground-cover or mulch. Of course, it is always advisable to control weeds before they go to seed. They can not easily come back without a new generation.