The shorter days and cooler nights of early autumn trigger unusual behavior among certain local gardeners. No sooner have they sent the kids back to school than they head for native plant nurseries and botanic garden plant sales, driving right past the everyday nurseries with their flats of bedding plants and sacks of grass seed piled sky-high.
As in all attempts to understand human behavior, there are "nature" and "nurture" theories to explain the drive to grow native plants. Is the desire to be surrounded by Matilija poppies and mountain lilacs inherited behavior peculiar to born and bred Californians, or does it reflect a taste acquired in early childhood?
Does it affect only those exposed at a tender age to the piercing scent of bay laurel or to the haunting charm of the satiny wildflowers known as fairy lanterns nodding on oak-shaded banks?
Certainly, there always has been a small but devoted group of gardeners that would prefer prickly phlox to petunias any day. With their own societies and nurseries, they have created gardens in tune with California's climate and seasons while remaining a fringe group among the great mass of plant lovers.
But this year, along with the changing seasons, have come changing attitudes toward native plants. With help from the current water shortage, native plants finally seem to have made it into the horticultural mainstream.
Actually, it would be more accurate to say that the mainstream has changed course, leaving our gardens drier in summer and therefore more hospitable environments for natives adapted to summer drought.
Many California natives bloom better and live longer the less summer watering they receive. That trait rendered them difficult to use in heavily irrigated gardens but makes them extremely appealing plants for today's water conservation landscapes.
Plant in Fall
There is no esoteric knowledge required to grow natives. You simply need to catch on to the rhythm of our wet and dry seasons. The keys to success are to choose appropriate species or cultivars for your growing conditions, to plant them in the fall, and to water them carefully during their first year in the ground. Following these steps, you can get a drought-tolerant planting established that will survive on minimum irrigation.
Before you buy any plants, take stock of your situation. As with any new planting, you need to bear in mind the slope, exposure and soil type of the area. Knowing these important factors, the salespeople at a native plant nursery can help you select plants that suit your growing conditions.
For a water-conserving planting, you also need to decide whether your garden, once established, is to receive regular summer irrigation (every week or two), occasional soakings (once every three or four weeks), or no summer watering at all. Most gardeners are used to buying plants they like and then adjust their watering schedule to suit the plants.
In water conservation gardening, you first decide how much you want to water and choose plants accordingly.
This is important if, for example, you are choosing a variety of ceanothus, or California lilac, a group of shrubs famed for their spring display of blue flowers. The cultivar 'Ray Hartman,' a long-lived large shrub or small tree, is at its best with a soaking about every three weeks in summer, and is a better plant to grow near a patio than on a very dry hillside. On the other hand, the Santa Barbara lilac ( Ceanothus impressus ) , once established, prefers places that are completely dry in summer.
Planting your natives as early in the fall as possible gives them the benefit of the entire rainy season to become established. Soaking rains encourage trees and shrubs to develop deep root systems that mine the soil for water and help them survive the long summer dry season. (Roots of toyon, or California holly, a large shrub prized for its red berries at Christmas, have been found to go 20 feet deep.) Until it rains, plan on watering your new plants every week or 10 days, especially if the weather is still warm.
Most Need Water
Even if the winter rains are excellent, drought-tolerant plants will probably need some watering during their first summer. As the rains taper off in spring, begin to water the new plants when you first see signs of stress, such as wilting or leaf fall.
The amount of irrigation needed will depend on local conditions--plants in quickly drying light soil and in hot, interior areas need more water than those in water-retentive clay soil or in coastal areas.
Try watering every week or 10 days and, if the plants seem to do well, wait longer before watering again. By the following summer, your drought-tolerant plants should be thoroughly established and able to survive with moderate or no irrigation.