Learn about the region Plant reference books targeting the Southwest can be difficult to find, but Greg Starr's new title, Cool Plants for Hot Gardens (Rio Nuevo Publishers, 2009; $25), is a standout in the genre. Starr, a horticulturist and teacher and the owner of Tucson's Starr Nursery, describes 200 water-smart plants that are specifically adapted to hot parts of the Southwest. You'll also find excellent photos, plants' natural elevation ranges, and which cities in the region are suitable for growing each plant.
Alternative grasses As drought persists and water-use regulations increase, consider replacing conventional turf-grass lawns with low-water varieties of blue grama (Bouteloua gracilis 'Hachita') or buffalo grass (Buchloe dactyloides 'Legacy'). Ready-to-plant plugs and blue grama seeds are available from High Country Gardens (800/925-9387).
Edible flowers and herbs Sunset climate zones 1a-3b: Set out transplants of calendula, chives, marjoram, oregano, rosemary, and society garlic. Zones 10, 11: Plant basil, bee balm, lemon balm, and pineapple sage. Zones 12, 13: Set out basil, chives, lemon verbena, and nasturtiums.
Low-water landscape plants Plant native and other low-water species now, when summer rains make digging easier.
Attract butterflies Sunset climate zones 10–13: Draw these pollinators to your garden by planting mist flower (Conocli-nium greggii) and blue mist flower (Ageratum corymbosum). Both are heat-loving perennials with puffy powder-blue blooms. They mix well with other butterfly magnets such as 'New Gold' lantana and attract clouds of showy orange queen butterflies.
Grow zephyr flowers Zones 10–13: For blooms that arrive with the season's humidity, plant these summer-flowering bulbs now through November. The white-blooming version (Zephyranthes candida) bears its crocus-like flowers from tufts of grassy foliage. Hybrid Zephyranthes x 'Prairie Sunset' has apricot-colored blooms and longer-lasting evergreen foliage during the hot months.
Plant veggies Zones 1a–3b: Sow seeds for arugula, bush beans, carrots, lettuce, peas, radishes, spinach, and turnips. Set out transplants of broccoli, brussels sprouts, cabbage, and cauliflower. Zones 10–11: Sow beans, corn, cucumbers, potatoes, and spinach. Zones 12–13: Sow bush beans, carrots, corn, green onions, summer squash, and turnips.
Control weeds Summer rains spur weed growth. In the early morning, before breezes pick up, either pull them by hand or spray with undiluted
white vinegar, avoiding desirable plants.
Prune oleander To encourage fullness without diminishing height on leggy or woody plants, prune out one-third of the branches at the plant's base. To reduce overall size, cut the entire plant to 12 inches, then fertilize and water well. Watch for malformed flowers and warty growths ― signs of oleander gall, a bacterial disease. Cut out the affected parts and throw them away. Between cuts, disinfect pruning shears in a bleach solution (10 parts water to 1 part bleach) to avoid spreading the disease.
Cut back tomatoes Zones 10–13: Rejuvenate your tired tomatoes by shearing them back to a height of 1 foot, then fertilizing and watering deeply. This will spur new growth, yielding a crop that will begin to ripen in September.
Deep-water plants Regular, shallow irrigation can cause salts to build up in the root zones of landscape plants. Flush the soil by watering
two to three times deeper than you normally do; for trees, leave a hose running at a slow trickle under the tree’s canopy
for six to eight hours.
Fertilize citrus Toward the end of the month, give trees their final feeding of the year with a citrus-specific fertilizer. Follow package directions for application rates and water thoroughly before and after feeding.
Reapply mulch After summer storms subside, cover bare spots in your garden with a new layer of mulch. If your garden is topped with gravel,
add more (take a handful of your existing type in a plastic bag to a local sand and gravel yard to best match the color and
size). Applying a fresh top-dressing is an easy way to give the garden a neat appearance without a complete makeover.
Next: Grow colorful carrots