UNITED STATES—Gardening involves weeds. Gardening outside of refined gardens involves more weeds. A few of such weeds are native species which grow where they are undesirable. Most of the most aggressive are naturalized exotic species. Collectively, they are an unpleasant consequence of unmanageable external biodiversity. They necessitate weed abatement.

Weed abatement is a standard procedure within refined gardens. Most know it simply as weeding. Ideally, it is harmless to desirable vegetation. It may be a relatively simple task where desirable vegetation excludes weeds. Also, weeds are less abundant where they lack sources of seed to regenerate. Timely weeding should eliminate much of their seed.

Unfortunately, no garden is isolated from external influences. Weed seed sneaks in from uncultivated spaces, adjacent gardens or beyond. Suburban and rural gardens might be close to wildlands or forests. Many of such weed seed sources are beyond the control of their victims. Some are merely easy to ignore because they are out of view or not in use.

Weed whacking is very different from weeding.

For some unused or unseen areas, weed whacking can be more practical than weeding. It entails cutting undesirable vegetation almost to grade with a motorized weed whacker. Manual weed whackers, although rare, are not extinct. Weed whackers are not selective. They can sever desirable annuals or perennials that mingle with undesirable vegetation.

The primary advantage of weed whacking is that it is fast and efficient. With good timing, it eliminates bloom or developing seed prior to dispersion of seed. Diminishment of seed inhibits subsequent proliferation, and is much safer for pets. Foxtail seed are notoriously hazardous. Besides, overgrown weed vegetation becomes a fire hazard as it desiccates.

Viable basal stems and roots that remain after weed whacking are not much of an asset. Many types of perennial and biennial weeds regenerate from such growth. However, to a very minor degree, such vegetation may contribute to healthy biodiversity. It may sustain some beneficial insects and soil microorganisms. Also, it can inhibit surface soil erosion.

Highlight: Smokebush

Mundane floral color and a lack of floral fragrance are no problems. Smokebush, Cotinus coggygria, compensates. Its uninteresting bloom reveals strikingly fluffy floral trusses for summer. These trusses eventually deteriorate to reveal exquisitely vibrant foliar color for autumn. This foliar color eventually deteriorates to reveal sculptural trunk form for winter.

Foliar color through spring and summer is likely the most striking attribute of smokebush. Most are boldly rich purplish bronze. Some are strikingly vivid yellowish chartreuse. The two extremes contrast splendidly. Old fashioned olive drab is now rare. Foliar color does not fade much. However, it suddenly transitions to fiery orange and red color for autumn.

Old fashioned olive drab smokebush can grow a bit more than 15 feet high and wide. Because it does not grow fast, only old specimens are so large. Most bronze cultivars do not get much higher than first floor eaves here. Chartreuse cultivars are likely to stay a bit shorter. Healthy young specimens might get wobbly if their canopies outgrow their roots. Aggressive pruning improves form and stability and can also enhance foliar color.

Tony Tomeo can be contacted at tonytomeo.com.