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.

Heavenly bamboo is an evergreen (semi-deciduous in cold winters) shrub native to eastern Asia from the Himalayan foothills to Japan, valued for striking year-round foliage that flushes pink-red in spring, turns green in summer, and blazes red-purple in autumn and winter, plus panicles of white summer flowers and persistent bright-red berries. It is adaptable, drought-tolerant once established, and undemanding in most soils from full sun to part shade. The honest catch is dual: all plant parts — especially the berries — contain cyanogenic compounds, and excessive consumption of the berries can be lethal to cedar waxwings and is toxic to cats and livestock, making it a poor choice wherever birds congregate to feed on winter fruit; and in the southeastern United States it is classified invasive (Florida Category I) and is best replaced with a non-invasive native alternative.

Japanese holly is a dense, small-leaved evergreen shrub native to Japan, Korea, eastern China, and adjacent regions of eastern Asia, widely grown as a boxwood substitute for formal hedging and topiary. It tolerates heavy shearing well and thrives in acidic soils in a range spanning USDA zones 5b-8b. The honest catch is twofold: the glossy black berries are toxic to humans and pets (a genus-wide trait of Ilex), and the species is listed as invasive in parts of the eastern United States, where bird-dispersed seedlings colonise native woodland edges.

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.