Ever see a 100-foot-tall wisteria?

John and Carol Barany's towering Norwegian spruce becomes a bit of a dandy each spring, sporting brilliant lavender-purple wisteria blooms from its base to the topmost tip of its 100-foot height. Growing on one of the highest hills in Yakima, Washington, the tree is visible throughout much of the elegant historic center of the city.

Approximately 10 years ago, Carol started pulling out undesirable bushes and Oregon grape from under the spruce and discovered the neglected, never-blooming wisteria bush. Since then, she has tried to keep from irrigating in that area for fear it would stimulate the roots of the unwanted underbrush. Once cleared of competing plants, the wisteria began to produce vast amounts of vegetation before it started blooming. Then, it just exploded, she said.

"We planted another wisteria about ten feet from the volunteer when we moved in 26 years ago. It never bloomed, and, in fact, died this year,"Carol said. (The dead wisteria can be seen against the house.)"We have probably done everything wrong in terms of sound gardening practices by even encouraging this partnership," she added, but said she is resigned to letting the volunteer wisteria have its way. Whether the stress from the aggressive and heavy vine eventually dooms the spruce is anyone's guess. But for now, the Baranys are content letting the two work it out without benefit of water or pruning.

'Abalone Pearl,' a 4-year-old peony, offered two flowers this week‹after more than 1,300 days in the ground. Pitiful you say?Plenteous, in fact, because each flower requires attention and appreciation. Blooms remain about three days from plump bud to petal drop. Petals, called semi-double, tuck in layers but spaciously reveal the stamens and shapely carpels, teal tipped with pink. The elegant details harmonize. As if this flower required any other attractions,the fragrance strikes me as lightly spicy, a bit like fresh nutmeg.

Observing this flower, I'm experiencing the joy of the transient. Gardeners often remark that growing plants and living with the changes in plants brings on metaphorical thinking.

As a child, I wondered how a large flower‹like 'Abalone Pearl' at six inches across‹could emerge from a small bud. Even after fifty years of gardening, the questions and wonder of my childhood remain. The growth of one peony wraps my thoughts in mystery‹the mystery of how long a single moment can seem.

Garden advisors make lists of "long-blooming perennials with six weeks of bloom." Yarrow and coreopsis, feverfew and Shasta daisy pump blooms vigorously and rather constantly over the summer. Those plants have their uses and their individual beauties. What touches me more deeply,though, comes with the brevity of a peony flower's life: 1,300 days settling in, roots growing, to show this awed gardener a few hours' glimpse of perfect beauty.
Does your garden offer a similar joy of the transient?

Newspaper and cardboard enjoy popular use in gardens, landscapes, and restoration sites as weed barriers. The major differences between these sheet mulches and most other organic mulches are both structural and chemical. Sheet mulches are two dimensional and constructed mostly of cellulose, while other common organic mulches are chunkier, three dimensional materials with more complex chemistry. Let's compare their characteristics and find out which ones work best for specific situations:

Desirable attributes of mulches

1. Improved soil hydrology and aeration. The more permeable a surface is, the faster water and air will move through it. While this is obvious, less so is the realization that a sheet mulch by its nature will reduce water and air transport between the soil and the atmosphere. So even though sheet mulches may initially increase soil water retention by reducing evaporation, over the long term they will create soils that are unnaturally dry and possibly lacking in oxygen.

2.Moderating soil temperatures. Thick applications of coarse mulches are best in protecting soils from summer highs and winter lows. Sheet mulches provide limited protection.

3.Increased soil nutrition. While all organic mulches will contribute to soil nutrition, those that decompose more rapidly,such as green materials, contain a wider variety of plant nutrients.Paper products are limited in this regard.

4.Degradation of pesticides and other contaminants. By providing a habitat for active and diverse microbe populations, chunky organic mulches can help detoxify soils. Sheet mulches are not colonized by a diverse number of microbes.

5.Improved plant establishment and growth. Sheet mulches that act as barriers to water and air movement will encourage root growth on top of the mulch, injuring desirable plants when and if the sheet mulch is removed. Perhaps for this reason coarse organic materials generally rate higher than sheet mulches in comparative field trials.

6.Disease reduction. Coarse mulches (but not sheet mulches) reduce water splash, which can carry pathogen spores to stems or leaves. The microbial populations that colonize many coarse mulch materials can also reduce soil pathogens, either through competition for resources or chemical inhibition. Finely-textured mulches, like sawdust, and sheet mulches, can increase disease incidence by preventing water and air movement and thereby creating poor soil conditions.

7.Weed reduction. Deep, chunky, organic mulches are more effective than sheet mulches in controlling weeds over the long term. Certain organic mulches, such as wood chips, may inhibit weeds through the leaching of allelopathic chemicals naturally occurring in the wood. Additionally, the protected soil habitat created by the use of coarse mulches can increase beneficial organisms that prey upon weeds or eat their seeds.

8.Aesthetic improvement. While some may debate the relative aesthetics of bark mulch and wood chips, there is no doubt that both are preferable to cardboard or newspaper in the landscape.Nevertheless, neglected sheet mulches are common in restoration sites,adding an unattractive quality as overlying coarse mulch is scattered by wind, water, people and animals (see photo). Moreover, many insect and rodent pests can find shelter under sheet mulches, which allow construction of tunnels and nests.

Newspaper and cardboard can be effective for short-term control of weeds in annual beds and vegetable gardens. But permanent, ornamental landscapes, non-maintained sites, and restoration areas are not appropriate locations for these sheet mulches where long-term benefits are necessary.