Wall germander

Coronilla valentina is a compact, evergreen Mediterranean shrub in the legume family (Fabaceae), with a native range spanning the Mediterranean Basin from Portugal and Spain through Italy, the NW Balkans and Greece to the Aegean and Turkey, and south across northwest Africa to Libya. In a warm, sheltered garden spot it rewards with prolific, intensely honey-scented yellow flowers from late winter into summer and handsome glaucous foliage year-round. The honest catch is cold-hardiness: RHS rates it H4 (hardy to about 14°F), so it is borderline at the cold edge of USDA zone 7 and is liable to be cut to the ground or killed outright in a hard freeze, demanding a sheltered south- or west-facing wall in colder gardens - and the whole plant is toxic to humans and livestock.

Aloe maculata (soap aloe, also called zebra aloe; long sold as Aloe saponaria) is a clumping, stemless succulent from southern Africa with broad, triangular leaves marked by distinctive "H-shaped" pale spots. It is grown for its flat-topped racemes of tubular flowers in shades of orange-red to coral and yellow, held on tall branched stalks that draw sunbirds, bees, and other insects. A tough, drought- and salt-tolerant groundcover that spreads by suckers, it suits rock gardens, dry borders, coastal plantings, and containers in warm climates. It is frost-tender: the RHS rates it H1C (roughly USDA 9b-11), so leaves are damaged below freezing and it needs protection or indoor wintering where frosts occur. The leaf gel is used traditionally for skin and other ailments, but the plant is recorded as harmful if eaten (handle with care; seeds are reputedly poisonous), so treat it as not for casual consumption around people and pets.

Cape honeysuckle (Tecomaria capensis, Bignoniaceae) is a vigorous, evergreen scrambling shrub from southern and south-central Africa, valued for tubular orange-to-apricot flowers borne erratically across much of the year. It reaches about 6.6 to 9.8 feet tall and wide as a free-standing shrub, or can be trained much taller on a trellis or wall, and is widely used for informal hedging and as a hot-color border or container plant. It is frost-tender (RHS H1C; roughly USDA 9b-11) - in cooler climates it is grown under glass or as a summer container plant and overwintered indoors. In frost-free, mild climates it can become weedy: it has naturalised and is treated as invasive in parts of Australia and on islands such as the Azores, so site it where suckering and self-layering can be managed. It is not a recognised edible and is not flagged as notably toxic, though several plant parts feature in traditional southern-African medicine; treat it as ornamental rather than for consumption. Note the accepted binomial here is Tecomaria capensis (POWO/GBIF); the widely-seen Tecoma capensis is a synonym.

A vigorous, scrambling, semi-climbing tender shrub that flowers almost without pause through the warm months, carrying broad clusters of soft sky-blue (or, in the white form, pure white) phlox-like flowers. Known as the Cape plumbago or Cape leadwort, it is native to South Africa (POWO, Kew) and is grown worldwide as an easy, long-flowering ornamental. The honest catch is its frost-tenderness: it is hardy only in USDA zones 9a-11, so in cold climates it is grown as a conservatory or large-container plant, or treated as a summer annual. Left to its own devices it climbs or sprawls 6 to 10 feet and needs support, or hard pruning, to keep its shape; the flower calyces are sticky and glandular and cling to clothing and animal fur (its own seed-dispersal trick), and it suckers. In return it is one of the best blue-flowered butterfly plants for a warm garden.

Glossy abelia is a garden hybrid shrub first raised in 1886 at the Rovelli nursery in Pallanza (Verbania) on Lake Maggiore, Italy, by crossing the Chinese species Abelia chinensis and A. uniflora; it has no wild native range. Its chief assets are a very long, fragrant late-season bloom - white to blush-pink bells from mid-summer well into autumn, when few other shrubs flower - combined with glossy, semi-evergreen foliage and a tidy arching habit that suits mixed borders and foundation planting. The honest catch is marginal hardiness: in zones 6 and colder the soft stem tips routinely die back in hard winters, demanding annual remedial pruning and a sheltered site, and the shrub can look ratty after a cold snap before fresh growth breaks in spring.

Sasanqua camellia is an evergreen shrub native to the forests of southern Japan - Kyushu, Shikoku, and the Ryukyu Islands - where it grows on forest margins and hillsides. In gardens it is prized as the earliest-flowering camellia, bearing fragrant blooms from September through January when almost nothing else is in flower, and it tolerates more sun and drought than its cousin Camellia japonica. The honest catch is cold hardiness: open flowers are blackened by hard frost, and the plant itself is reliably hardy only from zone 7a south, making it unsuitable for much of the northeastern and midwestern United States without meaningful shelter.