Whether you are starting a garden from scratch or planning improvements to an existing garden, it's a good time to consider the merits of Mediterranean-climate gardening. This style of gardening works in harmony with our Napa Valley climate, with its rainy winters and hot, dry summers. Mediterranean-climate gardening is water wise and a smart approach for Napa Valley residents interested in carefree gardening.

 

If you are considering installing a Mediterranean-type garden, or hoping to move your garden in that direction, you need to consider your own microclimate.

 

Microclimates are created by environmental factors such as proximity to marine influences, elevations, mountains, hills and even the amount of shade on a property. For example, Carneros and Calistoga represent the extremes of Napa Valley's microclimates. Carneros, with its nearness to the bay, enjoys cooling night and morning fog. Calistoga, in the inland valley, can expect many summer days of blistering sun.

 

Between these two extremes are many places with more moderate conditions. A garden in the hills of St. Helena may be at least 10 degrees cooler in summer than a garden in the valley below. In the winter, low open areas will be colder and much more susceptible to frost. In your own garden, you may have more than one microclimate due to wind direction, trees and locations of buildings and walls. You may need different plans to suit each area.

 

After analyzing your garden for its microclimates, you will be able to prepare a plan that puts the right plants in the right places. Research your plants' water requirements, then group them according to water needs. Some roses are thirsty, while others, such as the rambler 'Apple Blossom' and the climbing Rosa banksiae (both the yellow R. banksiae lutea and the white 'Alba-Plena') are drought tolerant.

 

Most salvias require only occasional water once established, but some types need moderate water throughout the summer.

 

Position plants that require frequent watering close to the house where you can monitor them more easily. For irrigation efficiency, combine those that need weekly watering in a second group, and the truly drought-tolerant in a third group.

 

When choosing plants, remember that Mediterranean-climate gardening doesn't limit you to cactus and gravel. The gardens of Tuscany and Provence are lush with lavender, iris and rosemary. Cypress, roses and olive trees are also part of the classic Mediterranean look, but you don't have to be limited to the classics.

 

One great reference guide is "Plants and Landscapes for Summer Dry Climates of the San Francisco Bay Region" by the East Bay Municipal Utility District (EBMUD). It lists more than 120 perennials suitable for our area. Annuals, drought-tolerant and water-wise grasses, shrubs and trees are also included. The photography is great and there are even some tempting cacti.

 

When you are aware of your microclimates and have drawn up a water-wise plan for plant placement, you will be ready to make Mediterranean-climate gardening work for you. September is the perfect month to begin.

 

Although many of the plants that thrive in Mediterranean climates are drought tolerant, most need regular moisture to get established. Planting in the fall just before the rainy season begins allows nature to fill this need. Fall planting also provides time for new plants to establish a good root system in time for the rush of growth next spring.

 

Plant now for a beautiful garden next year. For spring bloom, choose muscari (grape hyacinth), a bulb with fragrant purple or white flowers. Like the Pacific Coast hybrid iris and the so-called Dutch iris, it needs no summer water.

 

For summer, vines can provide vertical interest as well as shade. The fast-growing Solanum jasminoides (potato vine) offers a long season of small white flowers. Bougainvillea can give you bouffant sprays of bright color, but it is frost tender and may need protection in winter.

 

Wisteria needs little water once established. Wisteria sinensis 'Cooke's Special,' after a brilliant display in the spring, will continue blooming intermittently throughout the summer.

 

Hard-working perennials not to be missed include nepeta ('Walkers' Low' and 'Six Hills Giant'), lavender, salvia (sage), penstemon and Tulbaghia violacea (society garlic). None of these is a water guzzler; all thrive in our climate and are available for planting this month.

 

For more advice on gardening in a Mediterranean climate, plan to attend the City of Napa's free Water-Wise Landscaping Workshop Series. The first session is Thursday, September 20, on "Soils, Mulches, Design and More." The second session, on Thursday, September 27, is on "Perfect Plant Picks." Both sessions are from 6:30 p.m. to 8:30 p.m. at the Palusi Building in Kennedy Park in Napa. Call 707-257-9390 to reserve your space. All workshop attendees will receive a free CD-ROM on "Water-Wise Gardening in the Napa Valley."