Achillea

A drought- and heat-tolerant perennial in the daisy family with fern-like aromatic foliage and flat-topped flower clusters. Native to temperate North America, Europe, and western Asia; one of the most climate-resilient pollinator plants for full-sun beds, lawn alternatives, and naturalized meadows.

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.

Greek yarrow (Achillea ageratifolia) is a low, mat-forming alpine perennial from the mountains of the Balkan Peninsula, grown for two things at once: a dense, silvery, near-evergreen mat of narrow, toothed, softly hairy leaves, and clean white daisy-like flower heads carried on slender stalks just above it in late spring and early summer. It is a very different plant from the common yarrow of borders and meadows: instead of ferny foliage and a flat corymb of tiny florets, this species has simple silver leaves (the name ageratifolia means Ageratum-leaved) and comparatively large, solitary or few-headed white flowers with pale yellow centres, each about 0.8 to 1.2 inches across. It stays small, roughly 6 to 10 inches tall in flower over a mat only a few inches high, which makes it a natural for troughs, walls, rock gardens, gravel, and the sunny front of a sharply drained bed. POWO (Kew) gives its native range as the Balkan Peninsula, and it holds the RHS Award of Garden Merit for UK cultivation. The honest condition of success is drainage: it wants full sun and lean, gritty, freely draining soil, is drought tolerant once established, and resents rich, heavy, or winter-wet ground, which is what usually kills it. It is an ornamental rather than a culinary yarrow, and its open daisy heads are easy nectar and pollen for bees and hoverflies.

Sneezewort (Achillea ptarmica) is a hardy, clump-forming herbaceous perennial grown for its loose, airy sprays of small, button-like white flower heads from June to August, carried above narrow, linear, finely and sharply toothed dark-green leaves on upright stems. POWO (Kew) gives its native range as across Europe and temperate Asia - from Britain, Ireland, and Scandinavia through central and eastern Europe to Japan, Kamchatka, Sakhalin, and the Kuril Islands - and it is introduced and naturalised widely across North America (much of the northeastern US and Canada, plus the Pacific Northwest), so in North America it is a garden escape rather than a native. RHS lists it as a fully hardy perennial (H7) for full sun and moist but well-drained soil, and it is hardy across roughly USDA zones 3a-9b. The honest caveat is its running, rhizomatous rootstock: the species form spreads at the root and can colonise a border, so it is best given room, a contained spot, or the double, largely-sterile cultivars such as the popular Pearl Group / "The Pearl", which give cleaner, fuller white pompoms (long used as a cut flower) but still travel at the root. Its leaves have a long folk history - chewed they give a numbing, Sichuan-pepper-like tingle, and the dried plant was used as a sneezing powder, the source of the names sneezewort and ptarmica - so it is a pungent, parts-edible herb rather than a salad green. It is a good, accessible nectar source for bees and hoverflies.