Common hawthorn

Seven-son flower is a fast-growing deciduous shrub or small multi-stemmed tree native to cliffs and forest margins in Anhui and Zhejiang provinces of eastern China, where only about nine wild populations survive (IUCN Vulnerable). In gardens it earns its keep through an unusually long ornamental season: fragrant white flowers open in September, then the petals drop and the calyces swell and flush deep pinkish-red through October-November, extending the display well into autumn. The honest catch is size: it is genuinely vigorous and will reach 15 to 20 feet in a decade, making it unsuitable for small gardens unless committed to hard annual renewal pruning - and its spreading, suckering root system can colonize several feet beyond the canopy over time.

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.

Doublefile viburnum is a deciduous shrub native to China, Korea, Japan, and Taiwan, grown for its spectacular tiered, horizontal branching draped in flat lacecap flower heads in late spring. It earns its place as a four-season focal point - white flowers in May, blue-black drupes in late summer, and often vivid red-purple autumn colour - but the honest catch is its sheer footprint: mature plants can spread 13 to 16 feet wide with rigidly horizontal branches that resent hard pruning, and the fruit is not edible.

Viburnum carlesii is a slow-growing deciduous shrub native to Korea, the Japanese island of Tsushima, and adjacent parts of southeastern China, prized above almost all shrubs for its intoxicatingly spiced spring fragrance - dense, rounded clusters of pink buds open to white flowers with a cinnamon-clove perfume that carries across an entire garden. It settles into a tidy, broadly rounded habit of 4 to 6 feet and adds a secondary season of interest through red fruits that ripen to bluish-black in autumn, taken readily by birds. The honest catch is the rootstock: most retail plants are grafted onto Viburnum lantana, which throws vigorous suckers from below the graft union; if those suckers are not removed promptly, the coarser, unscented rootstock will eventually crowd out the named cultivar entirely.

Persian lilac (Syringa × persica) is a compact deciduous lilac (Oleaceae) of uncertain hybrid origin, thought to arise from a cross between Syringa × laciniata and S. afghanica; it has been cultivated in European gardens for centuries and carries no confirmed wild native range (Wikipedia). Growing 4 to 8 feet tall and spreading 5 to 10 feet wide with gracefully arching branches, it produces abundantly fragrant pale-lilac panicles in spring and tolerates more warmth than common lilac (USDA zones 4a–7b per NC State Extension; some sources extend the warm edge to zone 9). The honest catch is powdery mildew: this lilac is highly susceptible and must be sited with excellent air circulation and pruned to an open centre, or the mid-summer foliage will be heavily disfigured - a near-certainty in humid, sheltered spots. (Note: this is the Oleaceae lilac, NOT the toxic Melia azedarach that shares the name.)

Red escallonia is an evergreen shrub native to the slopes of the Andes in southern Chile and neighboring Argentina, where it grows in scrub and open forest from central Chile south to Tierra del Fuego. In gardens it earns its place as a fast-growing, salt-tolerant hedge or windbreak with masses of crimson tubular flowers from midsummer into autumn. The honest catch is frost-tenderness: below USDA zone 8 (or without a sheltered coastal microclimate) hard freezes kill stems to the ground, and in mild, humid climates such as the Pacific Northwest and New Zealand the plant has naturalized aggressively and should be sited with invasive-escape in mind.