Green and water-efficient

Sunset, August, 1988

And even more surprisingly, this new garden is near hot-summer Sacramento

The moss-covered boulders, rhododendrons, azaleas, ferns, hostas, Japanese maples, and variety of ground covers in this natural-looking garden might make you think it grows in the Northwest.

Surprise-this lush landscape thrives near hot-summered Sacramento. Yet just two years ago, the garden had little more than native oaks dotting its sloping site.

Homeowners Sharon and Ron Schwartzman wanted the look of a rhododendron glen but also wanted to preserve the site's interior live oaks (Quercus wislizenii).

But rhododendrons thrive in a much moister climate than the drought-tolerant trees do. The challenge was to create an environment that would let both types of plants coexist.

Throughout the garden, designer Dennis Tromburg of Zierden Landscaping installed a drip-irrigation system with low misters about 5 feet apart. Then he covered the ground with about 5 inches of mulch, creating a nutrient-rich, acidic medium for the shallow-rooted rhodies.

The misters run for only 20 minutes early each morning, spraying about 1/3 gallon each. The mist drifts over the low plants like a light drizzle, wetting the leaves and soaking into the mulch. But the moisture doesn't penetrate the ground, where it could potentially damage the oaks' roots. The oaks provide filtered shade, which slows evaporation from the mulch.

A word of caution: irrigation around existing oaks can increase the risk of oak root fungus (Armillaria) and water mold fungus. Keep mulch away from oaks' bases; direct misters away from trees.