Shop for cactus and succulents. Whether you're a beginning gardener or a serious collector, you'll find a huge selection of container-grown cactus and succulents ― including Lithops, or "living stones" ― offered by Tucson-based Plants for the Southwest (also known as Living Stones Nursery, lithops.com).
For a stunning flower show, plant an entire bed or border with sunflowers of different heights. At the back, sow seeds of tall varieties like 'Lemon Queen', 'Mammoth Grey Stripe', and 'Velvet Queen'; in the center put midsize kinds such as 'Tangerine' and 'Vanilla Ice'; in front plant petite 'Sunspot' or 'Teddy Bear'. You'll enjoy blooms from August through November. All are available from WildSeed Farms (wildseedfarms.com).
Wind-tolerant plants If you have a particularly breezy spot in your garden, consider landscape plants that can stand hot, dry winds. Among trees, shrubs, and vines, good candidates include bougainvillea, cape honeysuckle (Tecoma capensis), eucalyptus (most species), honey mesquite (Prosopis glandulosa), hop bush (Dodonaea viscosa), lace vine (Fallopia baldschuanica), lavender, palms, rosemary, and Texas ranger.
Grow butterfly attractors. In Sunset climate zones 12–13, plant Asclepias linaria and A. subulata, two low-water milkweeds that butterflies love in summer. These tall, sculptural plants are ornamental and cast bold shadows when planted along garden walls. Find them at nurseries that specialize in native plants.
Set out pomegranates (Punica granatum) in hot locations in zones 10-–13. Try ‘Wonderful’, which bears large fruit filled with red arils (the ruby-colored seed kernels). Trees will survive in poor soil on as little as 14 inches of rainfall a year, but for better fruit production, water weekly through the summer.
To quickly create a living fence, windbreak, or low screen, grow the Los Lunas form of giant sacaton (Sporobolus wrightii). This elegant grass reaches 8 to 10 feet and produces attractive amber seed spikes in autumn. It is an excellent native substitute for invasive pampas grass. Find it at High Country Gardens (800/925-9387).
Take advantage of upcoming summer rains by sowing seed for devil’s claw (Proboscidea parviflora) and summer poppy (Kallstroemia grandiflora) in zones 10–13. Both attract native pollinators.
Desert snowbush (Maireana sedifolia), also known as pearl bluebush, is an Australian shrub sporting silver teardrop-shape leaves. Desert snowbush is tidy enough to use around a pool and compact enough (to 3 by 3 feet) for small spaces. Since it hails from the hottest part of the outback, it is extremely drought tolerant. Try pairing it with gold or purple flowers like angelita daisy and moss verbena. Available at B & B Cactus Farm (520/721-4687).
Propagate prickly pear cactus. Among the easiest plants to propagate, prickly pear pads can simply be cut from the mother plant and stuck into the soil. They look great when arranged artfully in containers.
Water wisely. When landscape plants wither and die in June, overwatering is often the cause. Most drought-tolerant plants don't like wet "feet," so they're susceptible to root rot when warm, soggy soil conditions persist. To discourage rot, allow the soil to dry out between waterings.
When cactus and succulents become heat-stressed, you may notice a sudden wilting, yellowing, and wrinkling of skin in zones 11–13. If these symptoms occur, water deeply every one to two weeks and protect from afternoon sun.
To prevent sunburn on fruits and to reduce heat for better production, cover pepper and tomato plants with a canopy of 50- or 70-percent-density shadecloth (sold in rolls at garden supply centers).
Apply a 4- to 6-inch-layer of shredded bark or other mulch around annuals, landscape plants, and vegetables if you haven't done so already.
Give established palms their first feeding of the year with a palm-specific fertilizer. Feed cactus with a cactus-specific fertilizer or an all-purpose fertilizer diluted to half-strength
Shade southern African succulents, peppers, and tomatoes. Increase the shade (using up to 70 percent shadecloth) for aloes, ice plants, and living stones. Shield peppers and tomatoes with 50 percent shadecloth to increase fruit set and reduce sunscald. Keep all of the above under extra shade from now through September.