However, I very rarely recommend new specimens of either of these species for other landscapes. They simply are not appropriate unless their unpredictable moods and discriminating tastes are understood and accommodated by those wanting to adopt. Too often, I see oaks that were used as the token drought-tolerant trees within generously irrigated landscapes where they may thrive for many years, but will eventually likely succumb to decay before attaining their first century.

Of course, this limited life expectancy still exceeds what is expected of most other species, but oaks should be very long-term investments. They just don't do much during their first century and would be more appealing to those who inhabit the Santa Clara Valley centuries from now when BART comes to San Jose. Those who prefer oaks, even while young, should certainly plant them where practical. Nevertheless, selection of an appropriate species of tree is more important than selection of any other plant material.

Trees are the most substantial and essentially permanent features of a landscape. Annuals that are found to be inappropriate for a site after installation are easily replaced during the next season, but if a tree must be replaced, the process is expensive and involved and the replacement starts over as a juvenile specimen. I certainly do not recommend finding the perfect tree, but instead selecting a favorite tree and then determining if it is appropriate for the intended use. If so, and if any objectionable personality traits are acceptable, then go for it. If not, find another favorite tree and start the process over.

There really is no such thing as a perfect tree. Australian willow, water gum (Tristania laurina), purple leaf plum and crepe myrtle are perhaps among the best because they are so manageable, but they are just too puny where large trees are preferable. I was very impressed by the many crepe myrtles recently installed at the curbs of Spencer Avenue in Willow Glen that just happen to be perfect for the site. However, I would rather plant a silver maple in front of my home, even though I know this species is not the most appropriate and will eventually become somewhat troublesome.

Selection of street trees—those between the curb and sidewalk or adjacent to the sidewalk—is perhaps the most limited. Aggressive roots easily damage surface pavement. Height may be limited if utility cables are located in this area. Street trees must either naturally exhibit a reasonably high branch structure or be conducive to necessary pruning to maintain minimal clearance above the street and sidewalk. Smaller street trees may be lower branched if not permitted to extend where they might be sheared by truck traffic beyond where cars are parked.

Tree of the Week: Chilean wine palm

I rarely discuss species that are as rare as the Chilean wine palm, Jubea chilensis, because they are not enjoyed by many garden enthusiasts. In fact, I am only aware of five Chilean wine palms in the Santa Clara Valley. I thought it would be interesting simply because it is so strange and because anyone who has seen one might have wondered what it is.

Chilean wine palm usually grows slowly, but may eventually become 50 feet tall. Old fronds abscise completely and fall, exposing the distended gray trunk that may be as wide as three feet! The foliar canopy may be wider than 20 feet but seems proportionately sparse relative to the stout trunk. Fronds are typically arching and limber, but the photograph I found at Commercial Tree Care shows a specimen with oddly rigid fronds with minimal spread.

Horticulturist Tony Tomeo can be contacted at 408-358-2574 or at LGHORTICULTURE@aol.com.