What to Plant: Low Elevations

Fall is prime planting season in the low desert. Nighttime temperatures are cooling off, but soil remains warm enough to support rapid seed germination and root growth.

PEAS

Sow seeds of sugar snap peas, snow peas and sweet peas 3-4 inches from a trellis or another support structure that the vines can climb on. Growing peas on a vertical plane leaves room in your garden bed for other vegetables or flowers. Space seeds 3 inches apart. Peas do not need to be thinned. Remember, sweet peas are not edible—don’t make the mistake of eating any parts of the plant, as they contain known toxins.

HERBS

Cool-season herbs can grow from seed or be transplanted in the fall before temperatures dip into the low 30s. In addition to culinary staples such as oregano, rosemary, thyme, mint, lavender and cilantro, plant some catnip for the felines. Plant extra parsley and dill for butterflies—they are both larval host plants to the black swallowtail butterfly.

BULBS

Spring-flowering bulbs are more likely to sprout if exposed to cold temperatures for a few weeks before planting. Place newly purchased daffodil, tulip, narcissus, crocus and hyacinth bulbs in the vegetable crisper in your refrigerator four weeks before planting. Dig the planting hole deep enough so that the top of the bulb is approximately 2-3 inches beneath the surface. Cover the area with mulch to suppress weed germination.

TREES, SHRUBS AND VINES

Chaste tree (Vitex angus-castus) is a multitrunked large shrub or tree that produces spicy-smelling foliage and purple flowers, which are attractive to bees and butterflies. Bottlebrush (Callistemon citrinus ‘Little John’) forms a dense hedge and blooms bright red flowers. Passion vine (Passiflora spp.), larval host plant to the Gulf fritillary butterfly, is a frost-sensitive, flowering vine that climbs by tendrils. Dig the planting hole no deeper than the root ball, but twice as wide to encourage root growth into surrounding soil.

OVERSEED TURF

Overseed your Bermuda grass lawn for green turf all winter and spring. Begin by cutting the existing lawn quite short, to about 0.25 inch–0.5-inch tall, so there is no green showing. Next, use a broadcast spreader to apply cool-season turf seed, usually perennial rye in the low desert. It takes approximately 12 pounds of perennial ryegrass seed for each 1,000 square feet of lawn. Cover seeds with a thin blanket of composted steer manure, about 0.25-inch thick. The composted manure will help hold the seed in place and slow the drying process. Lightly water the seeds three to four times per day for the first two weeks. Don’t let the water puddle, as it will shift the seeds around, which will make the lawn clumpy. Once all of the seeds have germinated and the grass is at least 1 inch tall, start extending the length of time you water and decrease the frequency so that by mid-December you are watering every 5-7 days.

What To Plant: Low And Middle Elevations

WILDFLOWERS

Mix wildflower seed packets with a cup or two of sand to make them easier to scatter over bare soil. Avoid planting in areas that have been treated with pre-emergence herbicides, as they will also prevent wildflowers from germinating. To grow a feast for pollinators, look for seed mixes that include evening primrose, Mexican hat, lupine, bluebells, coreopsis and blue flax.

COOL-SEASON VEGETABLES

Start just about any vegetable harvested for its root, leaves or stems in the fall. Sow seeds of carrot, radish, turnip, rutabaga, beet, parsnip, leek, lettuce, arugula, spinach, cabbage, mustard greens and bok choy. Transplant artichoke, Brussels sprouts, broccoli and cauliflower. Enrich soil with compost to add organic matter and nutrients. Layer 3 inches to the top of the soil, mix it in with a garden fork, and smooth it out for an even germination seed bed.

Garden Maintenance: All Elevations

DROUGHT-PROOF

Take advantage of fall’s cooler temps and help plants become more resilient to drought. Adjust the location of where irrigation water is applied to the outer edge of the plant’s canopy, where most of the absorptive roots are found. Gradually increase the number of days between irrigation, so you are not watering trees any more frequently than once every two weeks by the end of November. Water deeply, at least to 3 feet for trees, 2 feet for shrubs and a foot for turf, vegetables and flower beds. Penetrating that deeply may take several hours, so apply water slowly enough that it doesn’t run off.

Garden Maintenance: Low Elevations

THIN VEGETABLE SEEDLINGS

Check seed packets to determine optimal spacing between plants and selectively remove seedlings to achieve that distance. Don’t throw them away; many vegetable seedlings are sold as “microgreens” and are delicious in salads and on sandwiches.

MANAGE WEEDS

Pull cool-season weeds as soon as they germinate to prevent them from going to seed. If you choose to use a pre-emergence herbicide to prevent weed seedlings from becoming established, follow the label directions completely, including product storage and disposal. Remember, herbicides won’t just kill weeds, they will also harm desirable plants, so don’t apply them on windy days when they can drift away. Also, avoid applying pre-emergence herbicides in locations where you plan to plant vegetable or other seeds.

Garden Maintenance: Middle Elevations

CUT BACK PERENNIALS

Prune perennials back to short stalks, 3-4 inches in length and cover roots with mulch to insulate against the coming cold.

Garden Maintenance: High Elevations

CLEAN UP GARDEN BEDS

Remove spent summer vegetables and flowers, chop them into 1-inch pieces and compost. Cover beds with a thick layer of mulch to prevent weed seeds from settling in and germinating.

FERTILIZE PERENNIALS AND BULBS

Spread a source of phosphorus, such as rock phosphate, ammonium phosphate or bone meal around plants this fall to support strong growth and blooming in the spring. Mix phosphorus into the soil and water right away so that it makes contact with the roots.