Add autumn color. Add these plants to your landscape now for years of fall color. Trees: crape myrtle ( Lagerstroemia hybrids), honey locust ( Gleditsia triacanthos 'Sunburst'), maidenhair tree ( Ginkgo biloba; plant fruitless male trees), and smoke tree (Cotinus coggygria). Shrubs: cotoneaster, dwarf red-leaf plum (Prunus x cistena), and Japanese barberry.
Start cool-season vegetables. Prepare beds by digging in a 4- to 6-inch layer of compost or well-aged manure. Sunset climate zones 1a-3b: Sow seeds of bok choy, carrots, chard, kale, lettuce, radishes, and spinach; plant garlic cloves (see Planting Garlic). Zones 10-13: As soon as daytime temperatures stay below 100°, sow seeds of arugula, beets, bok choy, carrots, chard, fava beans, kale, kohlrabi, leeks, lettuce, peas, and turnips. Plant onion sets and set out transplants of broccoli, brussels sprouts, cabbage, cauliflower, and chives. More: Guide to salad gardens
Plant palms. Zones 11-13: Take advantage of remaining warm weather by adding palms to your landscape. Suggested kinds include date palm (Phoenix dactylifera), Guadalupe palm (Brahea edulis), Mediterranean fan palm (Chamaerops humilis), Mexican blue palm (Brahea armata), and pindo palm (Butia capitata).
Set out spring bulbs. Zones 1a-3b, 10: Plant spring-blooming bulbs, including crocus, daffodils, hyacinths, and tulips. If you have cannas, dahlias, or gladiolus, dig up bulbs and tubers now and store in a cool, dry place for the winter. Zones 11-13: For best selection, buy allium, callas, crocus, freesia, hyacinths, narcissus, and zephyranthes bulbs now; put into paper bags and store in the crisper section of the refrigerator (away from fruit) until October, when soil is cooler, then plant them in the garden. Step-by-step: Planting bulbs in pots
Sow sweet peas. For luscious spring fragrance and color, you can't beat sweet peas. Soak seeds in water overnight to speed germination, then sow seeds 1 inch deep and 2 inches apart in enriched soil. Renee's Garden Seeds sells dozens of varieties, including early bloomers like 'Chiffon Elegance' and 'Velvet Elegance' as well as the new 'Electric Blue', 'Pastel Sunset', and 'Watermelon'.
Start strawberries. Zones 10-13: In well-drained, enriched soil, set out plants now to encourage growth, since bigger more mature plants mean more fruit next spring. Water deeply and regularly to reduce salt buildup in the root zone and protect from frost in colder areas. Varieties that grow well in the Southwest include 'Camarosa', 'Chandler', and 'Sequoia'.
Conserve water. Check out the website www.wateruseitwisely.com for advice on reducing water use indoors and out. One clever idea: Use ice cubes to water hanging plants, which helps reduce runoff. You can also request a free copy of the booklet Landscape Watering by the Numbers and download lists of low-water plants for your area.
Rejuvenate roses. Zones 1a-3b, 10: Let faded blossoms remain on plants to form fruits (called hips); this helps plants make the transition to winter. Zones 11-13: On hybrid roses, prune out dead or damaged canes, then cut remaining canes back by one-third. Fertilize and water thoroughly to encourage fall bloom.