The Cupertino Courier

Gardening

Gardeners can work around soil conditions for improved growth

By Tony Tomeo

From what I remember, it seemed that the remnant apricot orchard that formerly occupied San Thomas Park was quite happy. Although the trees had been disfigured by a lack of pruning during their final years, they were healthy and continued to produce good apricots until the trees were removed for construction of the park. They got all they wanted from the endemic soil and climate.

Since the orchard has been replaced by lawn, trees and shrubbery, the soil has been amended with organic matter and fertilizer, and is regularly irrigated. However, much of the shrubbery and some of the trees are not quite as happy as the old, abandoned apricot trees were when they lived there many years earlier. The land that was once so productive now seems adequate only to sustain even basic landscapes.

The soil should not take all the blame for this irony. Many of the problems associated with the soil are actually caused by what has been done to the soil. Irrigation, application of fertilizer, and incorporation of amendments are unnatural processes needed to sustain unnatural landscapes. Soil compaction is an unfortunate result of traffic within some landscapes.

The most common problem that I encounter in landscapes is excessive irrigation (over-watering). Even plants that do not mind moist conditions cannot tolerate soil saturation. Soils that are watered too frequently remain saturated simply because moisture is replenished faster than it can drain. Even otherwise well drained and generously amended soil are susceptible to saturation.

Salinity, pH, soil texture, drainage and fertility are other important factors to consider. Most soil problems associated with these factors can be corrected by appropriate applications of specific fertilizers, gypsum or other soil amendments, but identification of exactly what is needed can be confusing.

This is why Friends of Guadalupe River Park and Gardens is offering a soil science workshop with the soil consultant of the San Jose Heritage Rose Garden, Brian Debasitis. This class defines the components of soil, identifies some of the most common soil problems and explains how these problems affect the garden. Participants can bring samples or their own soil to view by microscope, and to get expert advice regarding any relevant problems.

The soil science workshop will be from 10 a.m. to noon on March 15, at the Visitor and Education Center of Guadalupe River Park and Gardens, located at 438 Coleman Ave. in San Jose. Admission is $15, or $10 for members of Friends of Guadalupe River Park and Gardens. Registration is required and can be arranged by telephoning 408.298.7657 or online at www.grpg.org.

Flower of the Week: common geranium

The obnoxiously bright pink common geranium, Pelargonium X hortorum, that is in my garden now has been with me since I was a sophomore in high school. I obtained the first cuttings from an uprooted plant in a compost pile. They grew into vigorous plants about 3 feet tall and wide, which provided many more cuttings. I planted the secondary cuttings throughout the garden, and into neighbors' gardens, and even at friends' homes. I later took cuttings with me to college in San Luis Obispo, and back again to the Santa Clara Valley.

Common geraniums are so easy to grow, and root so easily from cuttings that I have used them as a sort of cover crop for small areas. They controlled weeds, added a bit of organic matter to the soil, and kept the soil friable with their fibrous roots. Since the cuttings did not cost anything, I did not mind pulling up the mature plants when I needed an area to plant something else, such as vegetables, or even roses. Common geraniums are so appealing though, that they did not necessarily need to be replaced.

Flowers can be just about any shade of pink, as well as red, reddish orange, purplish red or white. Plants with larger floral trusses (flower clusters) tend to be smaller and weaker. The softly fuzzy leaves are rounded with blunt lobes. Common geraniums are also known as zonal geraniums because their leaves typically have darker zones paralleling the margins. Some have remarkably colorful borders, bands or variegations in white, yellow, red or brown.

Horticulturist Tony Tomeo can be reached at lghorticulture@aol.com or 408.358.2574.