Southwest

What to do in your garden in October

PLANTING

Add herbs. Sunset climate zones 10-13: Set out transplants of chamomile, chives, lavender, Mexican tarragon, oregano, rosemary, salad burnet, and thyme. Sow seeds of cilantro, dill, and parsley.

Plant a living screen. Create privacy or hide an unsightly view by planting a row of tall-growing shrubs. Zones 1a-3b: Try Canada hemlock (Tsuga canadensis), hawthorn (Crataegus monogyna), curl-leaf mountain mahogany (Cercocarpus ledifolius), or Leyland cypress (x Cupressocyparis leylandii). Zones 10 and 11: Plant Arizona cypress (Cupressus arizonica), Japanese privet (Ligustrum japonicum), or pyracantha. Zones 12 and 13: Choose desert mahonia (M. fremontii), hop bush (Dodonaea viscosa), myrtle (Myrtus communis), or Texas mountain laurel (Sophora secundiflora). Water plants regularly to get them established, then slowly taper off to less frequent deep soakings.

Set out permanent plants. Perennials planted in the fall develop strong roots that support vigorous new growth in spring and summer. Some good choices are Baja fairy duster, blackfoot daisy, Chihuahuan sage, deer grass, desert Christmas cactus, desert spoon, globe mallow, jojoba, Mexican grass tree, Mount Lemmon marigold, and Santa Rita prickly pear. Zones 12-13: October is the single best planting month for most trees. For beauty and shade, consider Arizona mesquite ( Prosopis velutina), which has an umbrella-like structure. The multibranched tree looks equally at home on a rustic ranch or outside a contemporary desert house. Or choose desert ironwood for its silvery evergreen canopy. For a distinctive Sonoran desert look, plant 'Desert Museum' palo verde; its multiple green trunks and yellow spring flowers can brighten any landscape. Look for trees at nurseries that sell native plants.

Sow a field of poppies. Most poppies grow easily from seed sown now, although some may lie dormant through cool winter months, then germinate when temperatures reach the mid-50s. For best results, mix the tiny seeds with sand before scattering on well-tilled soil, then rake them in or cover with a light sprinkling of soil. Keep moist until the seeds germinate. Good performers to look for are California poppy (Eschscholzia californica), Iceland poppy (Papaver nudicaule), and Shirley poppy (P. rhoeas).

Sow wildflowers. Zones 10-13: Plants wildflowers in full sun. Cultivate soil lightly, broadcast seeds, then cover them with a thin layer of sand or soil. Keep the area moist until seeds germinate. Choose reliable performers such as Arizona lupine (Lupinus arizonicus), prairie mallow (Sphaeralcea coccinea), showy Penstemon spectabilis, or white wild snapdragon (Penstemon cobaea), available from Plants of the Southwest (800/788-7333). Other wildflower choices include arroyo lupine, California desert bluebells, desert marigold, Mexican gold poppies, owl's-clover, and Parry's penstemon.

Bulb to try: spider lilies. Zones 12-13: In fall, these unusual bulbs produce 11/2- to 2-foot-tall leafless stems topped by stunning clusters of spiderlike blooms. Strappy green leaves appear after flowers die down. Lycoris radiata has coral red flowers with prominent spiderlike stamens; golden spider lily (L. aurea) has bright yellow flowers with shorter stamens. Plant in the ground or in pots early in the month. Choose a site that receives winter sun and summer shade (such as under the canopy of a deciduous tree). Zones 1a-3b, 10-11: Grow in pots, outdoors in summer and indoors in winter. Look for spider lilies at Plants for the Southwest in Tucson (520/628-8773). Start cool-season crops. Zones 10-13: Sow seeds of arugula, beets, bok choy, carrots, fennel, kohlrabi, lettuce, peas, radishes, spinach, Swiss chard, and turnips. Set out transplants of broccoli, brussels sprouts, cabbage, cauliflower, and kale. Plant garlic cloves and onion and shallot sets.

Transplant cool-season bloomers. Set out transplants of bachelor's button, calendula, chrysanthemum, dianthus, flowering cabbage, foxglove, larkspur, pansy, sweet alyssum, and viola. Zones 10-13: For fragrant color in February and March, plant sweet peas early in the month. Start from seed while the weather is mild for the best germination and strongest plants. Two very fragrant heirloom varieties are 'America' (crimson with ivory stripes; introduced in 1896) and 'Cupani' (maroon and purple; from 1699).

MAINTENANCE

Spread mulch. Apply a 4-inch-thick layer of mulch around plants to conserve moisture, insulate roots from cold, and discourage weeds. To estimate how much you'll need, first determine how many square feet you want to cover by multiplying the area's length by its width. To cover a 100-square-foot area 4 inches deep, for example, it takes about 1 1/3 cubic yards of mulch. For large areas, buy in bulk to economize.

Install a directional sprinkler. Garden beds that are irregularly shaped or long and narrow are difficult to irrigate without wasting water, especially when working with hose-end sprinklers. But the Noodlehead sprinkler was designed for just such a purpose. Composed of 12 mini sprinklers on short lengths of flexible tubing, the head allows you to put water exactly where you want it when attached to a hose or sprinkler riser. You can even point each mini sprinkler directly at the root zone of a particular plant, to help it get established. ($17; 541/549-8909).