Native plants hit the stage—in pots

Sunset, Nov, 1992 by Lynn Ocone

Here's how to grow them

CALIFORNIA NATIVE plants are too often relegated to the sidelines, even though their richness and diversity rival those of the common exotics we're accustomed to seeing on doorsteps and patios. But native plants, with their fascinating colors, forms, and scents, are easy to appreciate when shown off in containers.

Here, we offer gardening techniques for growing natives in containers and describe kinds that perform well in pots. Our recommendations reflect the advice of two native plant specialists: Bart O'Brien of Rancho Santa Ana Botanic Garden in Claremont, California; and Carol Bornstein of the Santa Barbara Botanic Garden.

SELECTING A CONTAINER

Most native plants in containers need good drainage, so choose a pot with a hole.

"The thicker the container, the better. Thick walls help insulate the roots from temperature extremes," says O'Brien. He recommends pots made of clay or concrete--these porous materials allow free passage of air and moisture. While this promotes healthy roots, it also allows soil to dry out quickly, so containers require frequent irrigation.

As an alternative to thick, heavy containers, you can double up lighter pots. Place one inside a slightly larger one; fill the area between the pots with damp peat moss or bark mulch.

Container size will depend on the type of plants you are growing. Succulents thrive in small containers, but perennials should be planted in pots no smaller than 12 inches in diameter. Shrubby plants and plant combinations perform best in containers at least 18 inches in diameter. Containers should provide ample room for roots; the larger the container, the greater the root development.

POTTING SOIL MIX

A fast-draining, light-weight potting mix is usually best with native plants. Bornstein suggests mixing in some compost and a controlled-release fertilizer before you plant.

PLANTING

Slide the plant out of the nursery container. Check to see if it's rootbound; if roots form a solid mass, score them with a sharp knife and gently spread them apart.

Cover the planting container's drainage hole with screen to prevent soil loss. Partially fill the container with moistened potting mix, and set the plant so its crown is about 3 inches below the rim. Fill in with moist soil, but don't bury the crown.

To help retain moisture, cover the soil surface with a layer of shredded bark or composted leaves.

MAINTENANCE

In the ground, many native plants are extremely drought tolerant. But in containers, where roots are restricted, most require regular water (exceptions are dudleya, rush, and yucca, which can survive periodic dry soil). Generally, let the soil dry out just slightly between waterings. But some plants, such as golden and cardinal monkey flowers (Mimulus), perform best with constant soil moisture.

Water so all of the soil is moistened and excess water runs out the drainage hole.

Fertilize plants infrequently. Bornstein top-dresses containers with controlled-release fertilizer every three to nine months.

To maintain a neat, compact appearance, many flowering perennials and shrubs should be cut back and shaped when their flowers fade. Most benefit from a light pruning of about a third of the length of flowering stems; this prompts the best bloom later. Some plants, including California fuchsia, require a hard heading back to look their best.

CHOOSING PLANTS

Virtually all native plants can be grown in containers, but bulbs, grasses, succulents, perennials, and subshrubs are best suited to this method. The roots of these smaller plants adapt most readily to the constraints of containers. See chart at left for suggestions.

Planting can take two approaches: a single plant per container, or a planting that combines natives of various forms, colors, and textures.

For a simple combination, try mixing species of dudleya like the broad green-gray of D. brittonii with the tapered bright green or gray of D. farinosa.

When mixing several types, consider plant height. Place low or cascading plants like California fuchsia at the container's edge, slightly taller ones just inside, and tallest plants in the center.

NATIVES FOR CONTAINERS, LOW TO TALL

Low-growers, to 1 foot

Beach aster (Erigeron glaucus). Perennial with blue-green leaves, lavender daisylike flowers.

California fuchsia (Zauschneria californica). Types like 'Everett's Choice' and 'Select Mattole' cascade with scarlet trumpet flowers.

Dudleya. Succulents with rosettes of cylindrical or flat leaves, green to chalk white. Sensitive to over-watering.

Manzanita (Arctostaphylos). Ground cover types like A. edmundsii parvifolia, A. 'Emerald Carpet', and A. uva-ursi have branching structure, showy bark, and white to pink blossoms.

Monardella macrantha. Cascading form with dark green leaves, scarlet flowers. Needs good drainage.

Red fescue (Festuca rubra). Showy varieties of grass with 4- to 8-inch steel blue or blue-green blades.

Saffron buckwheat (Eriogonum crocatum). Perennial with woolly white leaves, clusters of sulfur yellow flowers.

Wallflower (Erysimum concinnum). Short-lived perennial with fragrant cream blossoms.