In case readers are wondering, we were chucking and sometimes flinging the fuchsias into a dump site because the plants had outgrown their marketability and were no longer consistent with the impeccable quality expected from Cavanaugh Color. Every species involved in nursery production has a limit to confinement or graduation into a larger container.

Many species, such as fuchsias, may be pruned severely and permitted to regenerate and become salable later if too many become salable at the same time. Some species may even tolerate this procedure several times. However, inferior structure and gnarled growth eventually results from continued excessive pruning.

Confined roots may also be damaged as the growing medium (soil) decomposes or if severe pruning exposes the cans to direct sunlight, causing the black vinyl to become heated and "cook" the roots. Root system structure is very easily compromised as roots that are unable to disperse will naturally circle within the confines of the cans. Specimens that seem too large or mature relative to the container likely are and may express any of these symptoms.

Fortunately for those of us who grow nursery stock, species with fibrous roots, such as citrus or rhododendron, may simply be "shifted" or "graduated" into larger containers. Species that prefer to extensively disperse roots, such as most native species, can also be grown in larger containers but adapt more easily to the garden environment while juvenile than when mature. Large specimens of such species may require considerably more time to recover from confinement. When selecting nursery stock, it is therefore important to know what size or maturity is appropriate for each species.

For example, No. 1 (one gallon) specimens of the various eucalyptus grow like weeds. In fact, they easily grow larger than large (boxed) specimens installed at the same time. The No. 5 or No. 15 specimens are a good compromise because they are substantial enough to tolerate minor abuse but not too large to have been confined. I once inspected 58 red gum eucalyptus grown in 48-inch boxes that were unable to adapt to their landscape and had begun to die. Smaller No. 5 specimens would have cost less than two of the larger specimens but would now be quite a forest.

Incidentally, the Spring Native Plant Sale organized by the Santa Clara Valley chapter of the California Native Plant Society is an excellent source of more than 100 species of native annuals, perennials, shrubs and trees, as well as relevant books, posters and garden accoutrements. The larger plants are in one-gallon cans and should therefore easily adapt to the garden.

The Native Plant Sale runs from 9 a.m. to 4 p.m. on May 10 and is located at the California Native Plant Society Nursery at Hidden Villa Ranch, 26870 Moody Road (two miles west of Foothill College) in Los Altos Hills. More information may be obtained by calling 650.941.2586, emailing gstigall@aol.com or visiting www.stanford.edu/~rawlings/blazcon.htm.


Tree of the Week: Empress Tree

The deciduous, heart-shaped leaves of the empress tree, Paulownia tomentosa, may be as long as 10 inches and as wide as 6 inches—or much larger among severely pruned specimens. Although typically less than 30 feet high and wide, empress trees may grow rapidly and larger. Floral buds develop during autumn and are sensitive to winter weather; they may freeze if too cold or abscise if too warm. The fragrant, tubular flowers are pale bluish-lilac, with spots and yellow stripes within, and begin blooming prior to foliation. They are only 2 inches long but comprise upright clusters as large as 10 inches. Interesting "top-shaped" seed capsules may remain suspended for more than a year, only to be replaced by more. Aggressive roots and foliar and floral litter may be objectionable within refined landscapes.

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