Southern California

What to do in your garden in September

SHOPPING

Buy spring bulbs. Shop for anemone, daffodil, Dutch iris, freesia and other South African bulbs, and ranunculus while there's an ample supply. In the high desert ( Sunset climate zone 11), plant immediately; elsewhere, plant any time through October.

Order bare-root plants. Winter is the best time to plant roses and stone fruit trees, but if you already know what you want, place an advance order during Armstrong Garden Centers' preseason sale, which runs through October 31. About 700 kinds of roses, including 54 David Austin varieties, and 200 kinds of fruit trees will be offered this year.

PLANTING

Fall in a pot. With the abundance of suitable-for-container foliage plants now available in copper and burgundy shades, every home gardener can enjoy autumn color, says Brita Lemmon of Brita's Old Town Gardens (562/430-5019) in Seal Beach. Her favorites include 'Ceylon' acalypha, 'Toffee Twist' carex, 'Velvet Night' heuchera, and 'Cheryl's Shadow' geranium. If you want flowers too, add coppery mums or 'Terra Cotta' million bells.

Herbs. Plant seedlings of mint, parsley, rosemary, sorrel, tarragon, thyme, and other perennial herbs. Sow seeds of arugula, chervil, cilantro, and dill.

Sweet peas. September and October are the best months to plant all varieties of sweet peas.

Winter vegetables. Starting midmonth, coastal (zones 22-24) and inland (zones 18-21) gardeners can plant winter crops. Sow seeds or plant seedlings of beets, bok choy, broccoli, brussels sprouts, cabbage, carrots, cauliflower, celery, chard, collards, kale, lettuce, green and short-day onions, parsnips, peas, potatoes, radishes, rutabaga, spinach, and turnips. In the high desert (zone 11), plant lettuce, radishes, and spinach.

MAINTENANCE

Feed most permanent plants. Fertilize established trees, shrubs, groundcovers, and warm-season grasses like St. Augustine. Feed roses one last time this year for a strong fall bloom. Don't feed California natives or drought-tolerant Mediterranean plants.

Nurture camellias. To foster good bud development, keep plants moist but not excessively wet. Feed monthly through January with a bud-promoting fertilizer, such as a 0-10-10 formula.

Pinch pelargoniums. To encourage winter blooms, prune back pelargoniums to new basal growth. Pinch back leggy impatiens as well.

Shade seedlings. Protect transplants from sun with temporary shade. Lay a window screen, supported by four stakes, over the seedlings. Or stretch a piece of shadecloth between two stakes, staple it, and place the structure on the south side of the plants.

Treat hydrangeas. To help blue-flowered hydrangeas retain their color, treat soil around plants now with aluminum sulfate. Use 1 tablespoon per foot of plant height or 1/4 teaspoon per potted plant. Mix with water and apply to soil. Repeat treatment later in fall and again in early spring.