Magazine article Sunset

The Showiest Grevilleas

Magazine article Sunset

The Showiest Grevilleas

Article excerpt

This clan includes trees, shrubs, and ground covers

Like the mythical Proteus, the Greek "old man of the sea" who could assume many different shapes at will, the genus Grevillea seems to reinvent itself from one plant to the next. A member of the Protea family, this group of strikingly handsome plants from Australia - one of the oldest groups of flowering plants on earth - is incredibly diverse.

Grevilleas range from towering tropical trees and broad, spreading shrubs to alpine ground covers that crawl along the soil. The leaves - just as variable - may be needlelike, stiff and oak-like, or so deeply cut that they appear lacy. They range from silvery gray to bright green to bronzy. The flower clusters are shaped like spiders or toothbrushes. "They're unlike anything else in the gardening world," says Steve McCabe of the University of California at Santa Cruz Arboretum. Their colors span much of the color wheel, but the most common tones are orange, pink, red, and yellow. Most types bloom over a long period, often starting in winter; some bloom much of the year.

And best of all, "most have flowers that are absolutely irresistible to hummingbirds," says Luen Miller of Monterey Bay Nursery in Watsonville, California. This is especially true of 'Long John' and 'Robyn Gordon'. "A garden of grevilleas and salvias will have hummingbird wars all year," he says. And deer don't touch most of the plants.

"There's been an explosion of interest in grevilleas," says Miller. "What you find in the trade now are far showier than well-known old-time grevilleas, such as G. 'Noellii'."

HOW TO USE GREVILLEAS

As striking as these plants are, grevilleas aren't for everyone. The ones Westerners use for landscaping look most at home in gardens with native, Mediterranean, and Australian plants, as well as durable shrubs such as escallonia and rhaphiolepis; grevilleas don't mix well with thirstier cottage garden plants. They're also somewhat tender (although hardiness varies), so planting is restricted to mild-winter climates with lows between 15 [degrees] and 25 [degrees].

With some notable exceptions, grevilleas generally grow to a substantial size, which makes them unsuitable for small gardens (although pruning can restrain some of them). And with only a few exceptions, they prefer good drainage. Most grevilleas do not grow well in alkaline, clay soil.

HOW TO CARE FOR THEM

Unless otherwise noted, plant grevilleas in full sun and well-drained soil that's low in organic matter. Don't plant them in low spots where water collects. Irrigate plants weekly the first year to get them established, then cut back watering to about once every three to four weeks in summer. Heavy, wet soil will kill them.

Grevilleas grow best in soils that are low in nutrients. They don't need phosphorus. In fact, "most grevilleas won't tolerate high levels of phosphorus and alkalinity," says Steve Brigham of Buena Creek Gardens in San Marcos, California. "In my decomposed-granite soil (about pH 7), they grow like gangbusters." If the foliage turns yellowish, apply iron and magnesium.

To restrain the size of grevilleas, prune after flowering. You can also prune the large ones into trees.

If you can't find the variety you want, have your nursery order it from Monterey Bay Nursery or Rosendale Nursery in Watsonville (both are wholesale only). …

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