The rural setting inspired the design concept – the rustic gardens of country villas in Italy and the south of France. This area of the world is famous for its wines and gastronomy. Its Mediterranean climate is also very similar to that of the Kenwood area of California's Sonoma Valley. The main garden has formal parterres with hydrangeas, two fountains, a rose garden, a large patio for dining and sipping at the visitor center. A more intimate and less formal courtyard garden sits between the existing chateau and the visitor center. The connection between the good life represented by the villa, the gardens, food as cuisine, and wine is manifested in a small demonstration vineyard between the main parterre and the winery building.
The garden is screened from the parking lot by a high wall which engages two formal entry pavilions. The wall and entry pavilions form three sides of a wooden pergola that is supported on columns along the south edge of the garden and that serves as the visual termination of the formal garden. Violet Trumpetvine (Clytosoma calistegoides) climbs the columns to cover the pergola which shades a small wall fountain composed of an ornamental brass spigot, hand crafted by Hans Liebscher, pouring water into a large oil jar with bright blue glaze. The blue of the glaze is repeated in the flowers of the Periwinkle ground cover under the hydrangeas of the central parterre and in the flower color of another variety of hydrangea in the courtyard between the new visitor center and the existing chateau.
Tightly clipped hedges are an important design feature of the garden. The garden is bounded on the east and west by four foot tall clipped hedges of Waxleaf Privet (Ligustrum japonicum – L. texanum). Arches of American arborvitae (Thuja occidentalis) trained over metal trellises break the boundary hedges and arch over the paths that leave the main central garden for the grounds beyond. The lower hedges of the central hydrangea parterre are of Japanese Boxwood (Buxus macrophylla japonica).
The dominant flower color in the garden is white, with some pale pink and rose. The dominant shrub plantings of roses, hydrangeas, and the Periwinkle ground cover provide these colors. Additional color is provided by a great variety of annuals and tropicals (the latter in summer months) that are planted in pots changed twice per year.
The southernmost parterre is filled with hybrid roses in white and pink. The roses used are 'Carefree Wonder', 'Gourmet Popcorn' with a spicy scent, and 'Iceberg'. The fragrant rose 'Sombreuil' is trained to climb the trunks of four Windmill Palms (Trachcycarpus fortunei). These palms were moved into the rose garden from elsewhere on the grounds. This variety of palm is one of the most cold-hardy. In the center of the rose parterre is a Sago Palm (Cycas revoluta).
Surrounding the central parterre and lining the paths are dwarf Satsuma Mandarin Orange trees (Citrus reticulate) in terra cotta pots set on low terra cotta stands in the classic Italian manner. The citrus in these posts is one of the coldest-hardy and is expected to take the level of frost this area experiences each winter. The fruit is small, bright orange in color when ripe, and very delicious.
The parterre in the middle of the garden is composed of four triangular beds filled with hydrangeas: 'Annabelle' Hydrangeas (Hydrangea arborescens cv. 'Annabelle') and the PG Hydrangea (Hydrangea paniculata cv. Grandiflora) two white flowered 'mop-head' forms, and the Mariesii Variegated Hydrangea (Hydrangea macrophylla var. normalis 'Mariesii Variegata') that has flat, 'lace cap' form flowers in very pale blue.
The ground cover in all four beds is the variegated Ralph Shugert Periwinkle (Vinca minor cv. 'Ralph Shugert'). The white and green foliage of this Periwinkle echoes that of the Mariesii Hydrangea. The Periwinkle blooms heavily in the spring and sporadically the rest of the year.
The northern bed in the Hydrangea Parterre has a nineteenth century, figural sculpture cast in zinc representing "Saint Jean." Facing south, she overlooks a small, circular fountain in the center of the parterre. This fountain recalls the fountain in the square in the center of the town of Sonoma, a few miles south of the winery.
The garden immediately to the south of the visitor center is dedicated to the daily sampling of the Chateau's wines. There is a broad, semi-circular patio, shaded by umbrellas, and filled with tables and chairs for the comfort and relaxation of the visitor. A three-foot high clipped hedge of the Waxleaf Privet contains the patio. Within the hedge are four equally spaced and hidden columns at the same height as the hedge. These support Italian terra cotta pots filled to overflowing with a mixture of flowering plants providing seasonal color.
The grassy parterre immediately to the south of the patio is surrounded by Waxleaf Privet hedge twenty-four inches high, and is shaded by a clump of native California Sycamores (Platanus racemosa) on the west. An Italian Stone Pine (Pinus pinea) provides shade on the east. This pine is the same species as the famous "Pines of Rome".
As one approaches the entry pergolas to the courtyards on either side of the visitor center, the plantings on the outside of the path contain Lanarth White Hydrangea (Hydrangea macrophylla cv. 'Lanarth White'), a 'lace cap' variety. In the winter and spring, Sweet Olive (Osmanthus fragrans) provides fragrance as well as Wallflower (Cheiranthus cheiri) and Stock (Matthiola incana). Lily Turf (Liriope muscari) and more Ralph Shugert Periwinkle are used as ground covers.
Chinese Trumpet Creeper (Campsis grandiflora) with scarlet flowers in summer is being trained to climb up and over the entry pergolas. Persian Ivy (Hedera colclrica 'Dentata Variegata') with deep green, gray green and creamy white foliage climbs the walls on either side of the pergola.
This garden to the west of the visitor center separates it from the original chateau. It has a variety of interesting plantings because it also has many microclimates vis-à-vis sunny areas and areas in full shade. In the shade are planted Rhododendrons, Gold Dust Plant (Aucuba japonica variegate 'Picturatea'), Flowering Maple (Abutilon grandiflora) with pale yellow flowers, Western Sword Fern (Polystichum munitum) and a tiny campanula with blue flower (Campanual portenschlagiana).
The sunny parts of the garden have their own plant palette. An Angel's Trumpet (Brugmansia candida), which has white flowers four to six inches long that perfume the night when open, is planted in the sun. Fragrance is also provided by the yellow flowers of Italian Jasmine (Jasminium humile) trained on the face of the rear wall between the Visitor's Center and the chateau. Towering above these plants is a very tall and very old Cordyline australis transplanted into this part of the garden from elsewhere on the property. Four tree-form 'Natchez' Crape Myrtles (Lagerstroemia indica var. 'Natchez') shade the terrace running the length of the west side of the visitor center and overlooking the courtyard. Filling the bed beneath the trees and repeating the white of its flowers are White Flower Carpet Roses, which are meant to twine and filter through Silver Dragon Liriope (Liriope spicata 'Silver Dragon'), which has white and green striped foliage.
Bordering the hemispherical intersection of the two orthogonal paths through the garden is four tree form 'Tardiva' Hydrangea (Hydrangea paniculata 'Tardiva'). The 'Tardiva' and the 'Blue Wave' hydrangeas continue the hydrangea theme of the main garden into this one. Clusters of pots with changing flower displays insure bloom in the garden all year.