When selecting plants for patios and balconies, consider those from habitats that most closely match your conditions, such as areas exposed to wind and sun, with limited water and soil, as well as large temperature fluctuations. Plants from areas like scrubland, screes, mountainsides, and deserts often make great patio plants.
A common thread among drought-tolerant plants is foliage that's hairy, waxy, hard, small, thin, and/or leathery. Deep taproots or extensive branching roots also help with drought resistance. Below are some examples of plants that can beat the heat!
(Those with * have some species that are even suitable for hot and dry conditions like in the desert Southwest.)
Trees: oak, hickory, ash, honey locust, pine, gingko, palo verde (Cercidium spp.)*, desert willow (Chilopsis linearis)*, saguaro*
Shrubs: serviceberry, St.-John's-wort, sandcherry (Prunus besseyi cistena), leadplant (Amorpha sp.), broom (Chamaecytisus spp., Cytisus spp., and Genista spp.), mountain mahogany (Cercocarpus montanus), juniper*, Mexican blue palm (Brahea armata)*, dalea (Dalea spp.)*, oleander*, blue sage (Salvia azurea)*
Perennials: Nodding onion (Allium cernuum), lychnis, flax, hyssop, thyme, Raydon's Favorite aster (Aster oblongifolius), prickly pear cactus*, penstemon*, rosemary*, globe mallow*
Alpine perennials: sedum, basket-of-gold (Aurinia saxatile), ozawa onion (Allium thunbergii 'Ozawa')
Desert perennials: agave*, aloe*, red yucca (Hesperaloe parviflora)*, yucca (Yucca spp.)*, angel's trumpet (Brugmansia spp. or Datura spp.)*
Annuals: petunia, cleome, cosmos*, dusty miller, cuphea (Cuphea spp.), pentas (Pentas lanceolata), zinnia*
Tropicals: crinum (Crinum spp.), agapanthus, amaryllis, spider lily (Ismene spp.or Hymenocallis spp.), gladiolus, rain lily (Zephyranthes spp.) *
Fruits and Veggies: okra, chile pepper, chives, melon, gourd*, persimmon, fig*