I have trouble telling the difference between agaves and yuccas, sometimes even confusing them with phormium or cordyline. All these spiky architectural plants look somewhat alike, and very different from anything grown in our grandmas' gardens. Unless our grandmas gardened in Phoenix. These bold perennials aren't your typical Northwest plants, which is, of course, what makes them such standouts in the garden.

Native from the southwest U.S. to Argentina, agaves have a remarkable range, growing out of cracks atop rocky mountains as well as thriving on tropical beaches. All agaves consist of a cluster of leaves, often toothed or spiny, radiating in concentric circles about a central base.

Some grow into 150-pound hunks that spread 2 feet wide, while others top out at 6 inches. The 200 North American species fall into two types: those whose flowers cluster along a tall spike, and those that throw up a stalk resembling a huge candelabra, each arm topped with a cap of flowers. Agaves bloom only once, which is why they're known as "century plants." That majestic flower stalk is the culmination of a long life (really 15 to 30 years rather than 100), for once an agave comes into flower it dies. To ensure survival despite such rare flowering, the clever things also reproduce little offsets, slowly spreading themselves about.

While agaves may not show up in cave paintings, they were as important to the Southwest native peoples as buffalo were to the Indians of the plains. Agaves served as a veritable general store, providing rope and thread as well as needles, food, soap, medicine, anesthetic, poison, alcoholic beverages and building materials. Most of these uses are long lost, but tequila is still brewed from Agave tequilana, and agaves show potential as a source of medicinal steroids. The Aztecs worshiped an agave goddess who could heal with a touch. Her name was Mayahuel, her 400 breasts representing the agave's generosity to mankind.

Primarily, we want to grow agaves because they are so handsome. Their spiny leaves, in shades of gray-green to powder blue, add unique texture to the garden. It is possible to grow nearly any agave in a pot, which can be moved indoors in the winter. Expect an agave's growth to slow down while inside, and don't water more than once a month.

Agaves are tender, but a few can survive our winters if given a warm, sunny location and good drainage. Water while the plant is becoming established but not much afterward, as agaves are succulents and store water in their leaves. In our climate, more agaves die from over-watering and poor drainage than any other reason. They can suffer from crown rot, so when you plant them, keep the crown slightly above the soil. Agaves look their best when mulched with gravel or stones. Plus, gravel will keep weeds at bay.

Ideal candidates for Northwest gardens include A. parryi var. parryi, the most cold- and wet-tolerant of the agaves. Its gray to light-green rosettes stay compact, reaching only 2 by 2 feet. A. parrasana looks like a head of cabbage with steel-blue leaves gathered into a tight cluster. A. lophantha has powder-blue, dagger-like foliage that reaches 3 feet. The wickedly toothed margins of A. montana 'La Peña' form a sensational profile on a plant that resembles an artichoke, and A. bracteosa has bright-green, spineless leaves splayed open like the arms of an octopus.

It is worth trying to find these plants at local nurseries; all are part of the hardy agave collection offered by YuccaDo Nursery (P.O. Box 907, Hempstead, Texas 77445; 979-826-4580; www.yuccado.com). Also check out "Agaves, Yuccas and Related Plants: A Gardener's Guide," by Mary and Gary Irish (Timber Press, 2000, $34.95).

Now In Bloom

Nurseries are filled in early May with fuchsias in a stunning array of colors beyond the traditional shades of pink and red. The narrow, tubular flowers of F. 'Coralle'come in soft shades of orange and salmon set off by velvety, olive-green leaves; F. 'Annabel' is free-flowering with double, snowy-white flowers.

Valerie Easton is manager at the Miller Horticultural Library. Her new book, "Plant Life: Growing a Garden in the Pacific Northwest" (Sasquatch Books, 2002), is an updated selection of her magazine columns. Her e-mail address is vjeaston@aol.com.