Shiny geranium

A tender perennial from Madagascar grown across temperate North America as a heat-loving summer annual - a mounding 6-18 inch plant in the dogbane family covered in flat five-lobed phlox-like flowers from June to frost. The species blooms rosy-pink to red with a darker mauve throat, and it shrugs off the hot, humid weather that wilts most bedding plants. Every part of the plant is poisonous: it is the natural source of the vinca alkaloids used in chemotherapy.

A fast, sun-loving member of the aster family grown as a warm-season annual, Gaillardia pulchella throws a long succession of 2-inch daisy-like flowers from early summer until frost. The ray florets blaze in bands of red and gold around a darker domed center - the firecracker coloring that gives it its name - on a wiry, branching 12-24 inch clump. It is built for hot, dry, sunny ground where richer-fed bedding plants sulk, blooming hardest exactly when summer heat peaks.

A compact, frost-tender warm-season annual from Mexico and Central America grown for its dense, fuzzy, thread-like ("flossy") flower clusters - most famously in soft true blue and lavender-blue, the trait that sets it apart from almost every other bedding annual, plus pink and white forms. It mounds into a clumping cushion 6 to 12 inches tall and about as wide, blooming from early summer until frost over soft, heart-shaped, slightly hairy leaves. It is easy and rewarding bedding, edging, and container color in full sun to part shade with steady moisture, but it is strictly look-don't-eat: the foliage and stems contain hepatotoxic pyrrolizidine alkaloids and are toxic if ingested.

A low, hairy annual or biennial with deeply divided leaves, pink flowers and a pungent smell when crushed. In Washington it is a Class B noxious weed and quarantined species, prohibited from sale, transport and distribution. The state weed board identifies it as a threat to western Washington forest understories, including beneath a closed canopy. Its status is regional: WCVP also records native populations in eastern North America.

A tender perennial from New Guinea grown almost everywhere in North America as a warm-season annual, prized for non-stop bright bloom in part shade - and, unlike common impatiens, in considerably more sun. It mounds 6 to 24 inches tall and 1.5 to 3 feet wide, carrying large, flat, five-petaled flowers in coral, salmon, pink, red, orange, lavender, and white above bold, often bronze-tinted dark foliage. Its real selling point is honest and practical: Impatiens hawkeri is resistant to impatiens downy mildew (Plasmopara obducens), the disease that collapsed plantings of Impatiens walleriana, making it the dependable shade-to-part-sun bedding plant where the common species can no longer be trusted.

The garden petunia is a complex Brazilian-derived hybrid in the nightshade family, grown almost everywhere as a warm-season bedding annual for its funnel-shaped, often fragrant flowers in nearly every color except true brown and black. Missouri Botanical Garden ranks it second only to impatiens in annual bedding-plant sales, prized for non-stop bloom from late spring until frost. It is a tender perennial hardy only in USDA Zones 10-11, so most of North America treats it as a single-season annual.