Convolvulus

Field bindweed is a low, twining, deep-rooted perennial vine in the morning-glory family, with arrowhead-shaped leaves and pretty funnel-shaped flowers that open white to soft pink. Do not be charmed: Plotwright lists it as a know-your-enemy entry, not a plant to grow. Convolvulus arvensis is one of the most difficult-to-eradicate weeds in the world. A single plant builds a perennial root and rhizome system that can reach more than 20 feet deep, regenerates from the smallest broken fragment, and seeds into a soil seed bank that stays viable for decades. It twines over and strangles crops, perennials, and shrubs, climbing anything it touches. It is listed as a noxious weed in many US states. Learn to recognize it, never plant it, and treat any patch as a long-term control problem. Its one honest virtue is that the flowers are an early and season-long nectar source for some bees.

Silverbush is an evergreen Mediterranean shrub native to rocky coastal cliffs in Italy, Croatia, and Albania (and reported from Spain), prized for its intensely silver, silky-haired foliage and a long succession of white funnel-flowers with pink-flushed buds and yellow throats from spring into summer. It received the RHS Award of Garden Merit (confirmed 2017) and thrives in full sun, lean alkaline soil, and excellent drainage that echoes its wild cliff-face habitat. The honest catch is soil moisture: Convolvulus cneorum is acutely intolerant of wet, heavy, or waterlogged soil and routinely dies over winter in damp conditions or clay, making drainage the single non-negotiable site requirement.