Ox-tongue

Tiger aloe (Gonialoe variegata, syn. Aloe variegata) is a compact, evergreen succulent native to the arid Karoo region of South Africa and Namibia, where it grows in semi-shaded rock crevices with sharp-draining sandy or gravelly soil. In gardens it excels as a bold container specimen or focal-point succulent, prized for its spirally arranged dark-green leaves banded with irregular white spots and its tall orange flower spikes that sunbirds mob in the wild. The honest catch is frost-tenderness: this plant cannot survive temperatures below 41°F and must be overwintered under glass in all but the warmest frost-free climates - and every part of the plant is toxic to cats, dogs, and livestock via anthraquinone glycosides in the latex layer.

Kalanchoe tomentosa is a slow-growing, evergreen succulent subshrub endemic to the rocky granite outcrops of east-central Madagascar, where it tolerates seasonal drought in arid and semi-arid scrubland. In gardens it excels as a tactile, silver-felted container or houseplant prized entirely for its velvety, brown-tipped foliage; it rarely flowers in cultivation. The honest catch is toxicity: the plant is toxic to cats and dogs and mildly toxic to humans, so it must be kept out of reach of pets and children - making it a poor choice for households with either.

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.

David viburnum is a compact, mound-forming evergreen shrub native to western China (its provenance usually given as the Sichuan / Yunnan region), grown for its bold, deeply three-veined glossy leaves, small clusters of white flowers in late spring, and - when fruiting - striking oval drupes in a distinctive metallic turquoise-blue. It holds the RHS Award of Garden Merit and suits the front of borders, shaded corners, and containers in cool-temperate to mild climates. The honest catch is a fundamental one: it is dioecious, so you must plant at least one male and one female together to get the celebrated blue fruit - a single plant in isolation will never berry, and many gardeners discover this only after years of waiting.

Japanese box is a compact, dense evergreen shrub long cultivated in Japan (where it was first described from cultivated plants of uncertain wild origin) with truly wild populations known from Taiwan, used for centuries for topiary, low hedging, and bonsai. Its fine-textured small leaves and naturally tidy habit make it one of the most widely planted formal garden shrubs in temperate regions, and the 'Faulkner' cultivar holds the RHS Award of Garden Merit. The honest catch is a double threat: all parts contain steroidal alkaloids (cyclobuxine) and are toxic to humans and livestock, and the species is under sustained pressure from box blight (Calonectria pseudonaviculata) and the box tree moth (Cydalima perspectalis), with B. microphylla documented as more susceptible than the common European B. sempervirens, so an established hedge can be defoliated within weeks.

Mountain hydrangea is a compact, deciduous flowering shrub native to the mountainous regions of Japan and Korea, where it grows in cool, moist, partly shaded conditions - and that cool mountain origin is the honest catch. Hardy through USDA Zone 6 when dormant, the plant breaks dormancy early and its new spring growth is reliably vulnerable to late frosts; a single late freeze in April can destroy an entire season's bloom on wood that would otherwise flower in midsummer. It is smaller and more refined than bigleaf hydrangea, with serrated leaves and distinctive lacecap flowerheads in blue or pink depending on soil pH, making it a graceful focal point for partly shaded borders where consistent moisture can be maintained.