Common zinnia

Jasmine tobacco, also sold as flowering tobacco, sweet tobacco, or winged tobacco, is a tender perennial in the nightshade family (Solanaceae) native to southern and southeastern Brazil, Paraguay, Uruguay, and northeastern Argentina. The true species grows 3 to 5 feet tall from a low rosette of large, hairy basal leaves with winged stalks, and from early summer to frost it carries long-tubed, star-faced flowers, white to greenish-yellow, that open in the evening and pour out a sweet scent through the night for moths. It is perennial only in USDA zones 10a-11b, so most gardeners grow it as a summer annual. Many plants sold as 'flowering tobacco' are compact hybrids (Nicotiana × sanderae and similar strains) up to 24 inches tall whose flowers open by day and are mostly unscented; for the night fragrance, grow the species from seed. Be aware that it is poisonous: every part of the plant contains nicotine, it is harmful if eaten, and the RHS advises gloves when handling it.

Globe amaranth is a warm-season annual in the amaranth family (Amaranthaceae), grown for its round, clover-like flower heads of papery, long-lasting bracts: bright magenta in the species (Missouri Botanical Garden PlantFinder), with cultivars in purple, pink, red, lilac, violet, and white. The true flowers are tiny white to yellow trumpets tucked among the bracts. Kew's WCVP gives its native range as Mexico, Central America (Guatemala, Honduras, Nicaragua, and Panama), and tropical South America (Colombia, Ecuador, Guyana, Bolivia, and Brazil). NC State Extension and Missouri Botanical Garden describe a compact, upright plant 6 to 24 inches tall and 6 to 12 inches wide that flowers from June until frost, takes heat and drought once established, and makes a classic everlasting: the heads keep their color when cut and dried. It is frost-tender. NC State Extension rates it winter hardy only in USDA zones 9 to 11, where it can be grown as a perennial; everywhere else it is sown or planted after the last frost and grown for a single summer, which is why both sources list it as an annual for zones 2 to 11. It is a Gomphrena, not an Amaranthus: the amaranth in its name is the family it shares with love-lies-bleeding and the grain amaranths. It also shares the name bachelor's button with the cornflower (Centaurea cyanus), a different plant.

A compact, mounding deciduous shrub bred in the 1930s by crossing the East Asian species Caryopteris incana (southern China, Taiwan, Korea, Japan) and C. mongholica (Siberia, Mongolia, northern China) - it has no wild range of its own. Its defining virtue is a flush of vivid blue-to-violet flowers on the current year's growth in late summer and early fall, a period when little else in the garden blooms, combined with aromatic gray-green foliage and exceptional drought tolerance once established. The honest catch is its borderline hardiness at the cold edge of its range: in zones 5–6 the woody stems routinely die to the ground in winter and the plant resprouts from the base each spring, behaving more like an herbaceous perennial than a shrub - gardeners in those zones should hold back pruning until new growth confirms the crown has survived.

A dwarf, evergreen Mediterranean sub-shrub with intensely aromatic silver-grey needle-like leaves and clusters of small, long-lasting yellow button flowers in summer. Native to the dry, rocky ground of the western and central Mediterranean basin, it is prized for its bold textural foliage and the illusion of a curry scent - although the plant has no culinary relationship to curry spice and its flavor largely disappears on cooking. The honest catch is hardiness: Helichrysum italicum is reliably winter-hardy only to about USDA Zone 8 (around 10°F); in colder climates it either dies outright or must be overwintered frost-free, and even within its range it is short-lived on heavy, wet soils where winter root rot claims it quickly.

Grecian horehound (Ballota pseudodictamnus, accepted name Pseudodictamnus mediterraneus) is a compact, mound-forming evergreen subshrub native to dry Mediterranean regions of southern Greece, Crete, southwest Turkey, northeast Libya, and northwest Egypt, where it grows on rocky, sun-baked slopes. Its nearly circular, silver-felted leaves and small pink late-spring flowers (largely hidden among the foliage) earn it a place in any drought-tolerant planting, and it holds the RHS Award of Garden Merit. The honest catch is hardiness: while it tolerates brief dips to around 14°F (USDA zone 7b), prolonged wet cold kills it reliably, so in climates with cold, wet winters it must have razor-sharp drainage or it rots at the crown - a combination of frost and wet soil is almost always fatal.

Aubrieta (Aubrieta deltoidea) is a low, mat-forming evergreen perennial in the mustard family (Brassicaceae), native to the rocky hillsides of southeastern Europe - primarily Greece, the Aegean Islands, Crete, and adjacent Mediterranean coasts. It is one of the most reliable spring-flowering ground covers for sunny, well-drained spots: cascading sheets of violet to deep pink four-petalled blooms from March through May, attractive to bees and bee flies. The honest catch is that without a hard cut-back immediately after flowering, plants become woody and bare in the centre within two or three years, collapsing from a tight carpet into a tired, gappy mat.