Few trees survive the high winds, salt spray and heavy fog that characterizes seaside landscapes along the Pacific coastline. The Monterey Cypress (Hesperocyparis macrocarpa) is one of the best, growing in U.S. Department of Agriculture plant hardiness zones 7 through 10. Spreading to 40 feet wide with a trunk up to 6 or 8 feet in diameter on older specimens, this evergreen tree is great for coastal windbreaks. The Coast Live Oak (Quercus agrifolia) often grows wider than its height, with its long limbs sometimes growing laterally along the ground. Hardy in USDA zones 9 to 10, this specimen grows quickly into a massive gnarled tree with lots of character.
The mountains along the Pacific Coast are home to the tallest trees in the world -- the Coastal Redwood (Sequoia sempervirens). After several hundred years of growth, these giants can reach over 300 feet in height with trunks 15 to 20 feet in diameter. They grow free of any pests or disease in USDA zones 7a to 10a and make a stunning specimen or tall screen in home landscapes. The Douglas Fir (Pseudotsuga menziesii) is hardy in USDA zones 5a to 6b and grows well in landscapes throughout the Pacific Coast region, but reaches a more modest height of 60 feet.
The Pacific Coast may be foggy in the summer, but it actually receives very little rain. Free-draining, rocky soils in areas called "chaparral" support only very specialized plants. The Madrone tree (Arbutus menziesii) thrives in the chaparral and is adaptable to home landscapes, though it should not be watered at all in the summer. Hardy in USDA zones 7 through 9, madrone is a handsome evergreen tree with smooth, copper-colored bark, growing slowly to 30 feet or more. Gray Pine (Pinus sabiniana) is found in similar habitats and is hardy in USDA zones 8 to 10. It is fast-growing to 50 feet or more with long, airy grey-green needles and pinecones the size of a football.
A few small evergreen trees grow amidst the many giants of the Pacific Coast. Some species of Manzanita (Arctostaphylos spp.) grow as shrubs, but others are spectacular small trees with smooth burgundy-colored bark. "Dr. Hurd" is a variety for USDA zones 8 to 10 that grows up to 15 feet tall and tolerates garden conditions better than most. California Wild Lilac (Ceanothus spp.) is similar in having ground cover, shrub and tree forms, but is known for its fragrant sky-blue blossoms in spring. One common variety, "Ray Hartman," grows quickly to 20 feet and is hardy in USDA zones 8 to 10.