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The various species of Dracena may be grown as indoor or outdoor plants. When mature, Dracenas can reach 10 feet or taller.
Photograph by Shari Kaplan
Many plants naturalize over time, for better or for worse
By Tony Tomeo
Before urban development in the Santa Clara Valley, many native species of plants and trees thrived in a natural ecosystem. Many of the native species are logical choices for landscaping because they perform well in endemic soils and climate without environmental modification.
Many other species have been imported from areas with similar soils and climates because they are also perfectly happy here. Some escape into the wild and "naturalize"--perpetuating and behaving as they would at home. Unfortunately, many of these are more aggressively competitive than the native species and seriously disrupt what little remains of the natural ecosystem.
Many naturalized species become integral members of the "wild" California landscape. For example, the various species of eucalyptus that were imported for lumber and become naturalized are now a favorite source of nectar for the native monarch butterfly. Although naturalization of the eucalyptus has seriously altered the ecosystem, removal of some of the largest groves, particularly in San Luis Obispo County, would be temporarily disastrous to the monarch butterfly.
Water hyacinth is an aquatic plant that has been a very serious problem in the Sacramento River Delta since it escaped from landscape at a marina. Many grasses imported to feed cattle have crowded out the native California poppies, which were once so prolific. Some of these grasses have also become familiar lawn weeds.
Not all naturalized species were planted for specific purposes, but were introduced accidentally. The giant reed was used for many years as a packing material for china imported from China. As ships were unloaded in Sacramento, the reeds were dumped into the river and became established in the muddy banks.
Another example is the tumbleweed, which is so commonly associated with the American West. Its real name is Russian thistle, and it likely arrived as seed in spiny capsules attached to hooves of cattle.
Fortunately, not all naturalization is detrimental to the ecosystem. In fact, naturalization may be used to the benefit of home gardening. The most suitable of species require only minimal care and are most effective in unrefined or "natural" settings. Such species may become invasive weeds in small or formal settings. Once successfully established, plants should continue to perform annually.
Annuals grown from seed that are suitable for naturalization include but are certainly not limited to cosmos, nasturtiums, alyssum (Lobularia maritima), California poppy, California lupine, portulaca, violets, baby tears and Mexican evening primrose. Bulbs, corms and tubers include montbretia, crocus, freesia, grape hyacinth, narcissus and daffodils, as well as some of the ornamental oxalis.
Seed is easily broadcast on freshly tilled soil. However, bulbs, corms and tubers should be planted in a random, more naturally appearing configuration. Planting bulbs in "drifts" places them in sparse groups, leaving empty space between groups. Clumps form as bulbs split each year after bloom. Older clumps of some types of bulbs may eventually require division if crowded conditions minimize bloom capacity.
Naturalization of bulbs under groundcover is useful in more refined areas. If the groundcover requires mowing, it should be postponed until after the foliage of the bulbs has withered, indicating dormancy.
Plant of the Week: Dracena
Although several species of dracena are grown as houseplants, the most popular is likely Dracena dermensis. It may be grown on sheltered patios or lanais during warm weather, but must be brought inside through winter. Mature plants may eventually grow more than 10 feet tall. Leaves are usually about two feet long and about two inches wide. Although foliage of the two more common cultivars is uniformly deep green, each of the other cultivars exhibits distinctive variegation of white or gray.
Although grown mainly for the striking foliage, branch structure may also be picturesque if exposed. Flowers are inconspicuous and almost never seen. Good sun exposure is preferred. Too much shade will cause sparse growth and deformed stems. Soil must be well-drained and permitted to dry between irrigation.
Horticulturist Tony Tomeo may be contacted at 408.358.2574.
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Sunnyvale, California Since 1994
