A wise gardener in the Napa Valley designs largely with water-conserving native and Mediterranean plants. But entirely excluding the more exotic and dramatic tropical plants ignores part of the rich history of the Napa Valley.

Much of our valley was settled in the latter half of the Victorian era. During that time, gardening became wildly popular as plant hunters introduced many new species collected around the world.

Some of the most popular plants of that era were tropical, and many of the original estate gardens in the Napa Valley were designed around a tropical theme. Fortunately, many tropical plants from the mountain regions of the tropics are frost tolerant. And an amazing number of tropical and tropical-appearing plants are draught tolerant as well.

 Technically, a tropical plant is one originating between the Tropic of Cancer and the Tropic of Capricorn. Another method of classifying plants is based on the minimum temperatures they can tolerate. By that system, tropical plants are defined as those severely damaged when temperatures remain near freezing.

But we commonly use the term “tropical” today for any plants with bold foliage, bright flowers and an exotic appearance. Add a few of these plants to your landscape or to pots on your patio to bring a touch of the tropics to your garden.

Palms and cycads were among the favorites of our Napa Valley forebears. The sago palm is not a true palm but a cycad (Cycas revoluta). The young plant has an airy appearance and resembles a fern on steroids. It will grow slowly to 10 feet and requires only moderate water. The Mediterranean fan palm (Chamaerops humilis) is both draught tolerant and wind resistant. This hardy, multi-trunk palm with leaves in the shape of a fan also grows slowly to around 10 feet. Both make excellent focal points and do well in our climate.

For a lush, tropical look in a shady area of your garden, try a combination of plantain lily (Hosta), aucuba and kaffir lily (Clivia miniata). Hostas are available in an endless variety of dramatic and colorful foliage options. They go dormant and disappear in the winter but come back reliably every spring. To look their best, they need organically enriched soil and regular feeding during the growing season. Snails regard them as a gourmet offering, so be sure to use slug bait.

Japanese aucuba (Aucuba japonica) grows four to six feet tall, has beautiful, shiny leaves and is very resilient. My favorite is the cultivar ‘Variegata,’ which has deep green leaves splashed with bright yellow and brightens the shadiest areas of my garden where nothing else flourishes. To add a vivid spot of color to this grouping, plant a few kaffir lilies. The showiest have fiery orange, bright yellow or cream flowers. They are not frost tolerant but have survived for years near an east-facing wall in my St. Helena garden. These three plants require more frequent, shallow watering, so consider planting them in a designated hydro zone.

Another tropical-appearing plant that has been reliable in my shade garden is the Mystery gardenia (Gardenia jasminoides ‘Mystery’). This exotic cultivar has beautiful, shiny green foliage and a profuse bloom of intoxicatingly fragrant white flowers from spring to fall. Gardenias need fast-draining soil enriched with organic matter and some acid plant food every three to four weeks in the growing season. 

In Hawaii, blooms of the flowering maple (Abutilon) are used in combination with plumeria to make leis. While plumeria will not survive our Napa Valley winters, abutilon thrives here if you provide good drainage. It is an upright plant, eight to ten feet tall, with showy, lantern-like flowers in white, yellow, pink or red. It likes a bit of shade here and does best with some regular pruning to keep it from getting rangy.

One final showstopper in my garden is the tropical American native known as yesterday-today-and-tomorrow (Brunfelsia pauciflora ‘Floribunda’). The name comes from the dramatic color changes of the blooms. The flowers open deep purple, then fade to lavender and finally to white. It prefers partial shade and rich, well drained soil. The plants may contain poisonous alkaloids so keep them away from children and pets.

By using a few well-chosen and well-placed tropical plants, you can create the exotic look of the tropics and honor our Napa Valley heritage at the same time.

Master Gardeners answer questions Monday, Wednesday and Friday, 9 a.m. to noon, at the UC Cooperative Extension office, 1710 Soscol Ave., Suite 4, Napa, 253-4221, or toll-free at (877) 279-3065. E-mail questions by following the guidelines on the Web site, http://cenapa.ucdavis.edu