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Cotton lavender is a compact, mound-forming evergreen shrub native to the western and central Mediterranean, valued for its intensely silver-grey, aromatic feathery foliage and bright yellow button flowers in summer. In the garden it excels as a low edging, silver accent, or knot-garden structural element and tolerates drought and poor soils with ease once established. The honest catch is its short life in heavy or wet ground: without sharp drainage and a hard annual clip it becomes woody, open-centred, and collapses within three to five years, making site selection the single most important decision before planting.

Creeping cotoneaster is a deciduous spreading shrub native to the mountains of central and southwestern China, Nepal, and Taiwan, prized for its distinctive flat herringbone branching, tiny pink-white summer flowers, and masses of vivid red autumn berries that sustain birds through winter. It holds the RHS Award of Garden Merit and tolerates poor, dry soils on banks and walls where little else will perform. The honest catch is twofold: the berries are mildly toxic to humans and pets (cyanogenic seeds, GI-irritant flesh), and the plant self-seeds freely enough that it is naturalising widely in the UK and Ireland and is considered potentially invasive - a real concern before planting near wild margins or hedgerows.

A tall, sun-loving, drought-tolerant perennial in the daisy family, grown for its broad, flat-topped corymbs of tiny golden-yellow flowers held on stiff stems above finely divided, aromatic gray-green ferny foliage. Native to the Caucasus, Iran, and Afghanistan and long naturalized in gardens worldwide, it forms a tidy upright clump (rather than running like common yarrow) and is one of the most reliable, low-care pollinator and cut-flower plants for hot, dry, full-sun borders.

Idaho fescue is the plant that the small blue mound in every garden centre is imitating. That mound is almost always Festuca glauca, a European ornamental that dies out in the centre and wants replacing every few years; Idaho fescue is the western North American original, a densely clumping, long-lived perennial bunchgrass with the same fine blue to grey-green foliage on a plant roughly three times the size and with a genuine ecological job. It is a cool-season grass, flowering April to July on stiff stalks that stand about twice the height of the leaf tuft, and it is built underground rather than sideways: thick, deeply penetrating roots carrying symbiotic mycorrhizae, and no rhizomes at all. That is the whole difference between this grass and red fescue, the creeping lawn species in this same group. Idaho fescue never knits into turf, never repairs a gap by running, and cannot be mown as a lawn. What it does instead is hold a slope. The Lady Bird Johnson Wildflower Center calls it drought tolerant and excellent for erosion control, and notes the trap in the same breath: seedlings are only weakly competitive, and only mature plants become strongly competitive. Add that its seed is commercially available but not highly germinable, and the honest summary of establishment is that this is a two-to-three-year project on a weedy site, not a one-season fix. Two more caveats belong up front. There is no Missouri Botanical Garden PlantFinder profile for this species and no RHS Find a Plant entry, so this record rests on a native-plant database and an encyclopedia rather than on horticultural trial guidance, and it is thinner on garden performance than the fescue records around it. And its documented ground is western: rocky slopes and dry openings in woods, from British Columbia and Alberta south through the mountains to central California and Colorado. Nothing cited here describes how it behaves in a humid eastern summer, so this record does not guess.

An airy, see-through ornamental in the vervain family (Verbenaceae), native to South America and naturalized across the warm southeastern United States. NC State Extension describes an erect plant 2 to 5 feet tall on thin but strong red-marked green stems, topped from summer into fall by dense, flat-topped clusters of small tubular purple-lavender flowers held well above mostly basal, lance-shaped, serrated dark-green leaves. A perennial in USDA zones 7-11 (grown as an annual in colder climates), it is fast-growing, drought and deer tolerant, and a magnet for bees, butterflies, and hummingbirds - though it self-sows freely and some sources have labeled it invasive.

An aromatic, woody-based perennial grown above all for its finely divided, silky silver-grey foliage and pungent, bitter scent. Native across Europe, North Africa, and western and central Asia and widely naturalized beyond it, it carries small, dull-yellow flowers in nodding sprays in late summer above a soft mound of intricate, dissected leaves. It is the classic silver-foliage plant for contrast in a sunny, well-drained border. Note: this is the famous bitter herb of absinthe and vermouth, and it contains thujone, which is toxic in quantity, so it is grown for its foliage and never for eating.