Acidanthera bicolor (Gladiolus callianthus). Pure white, 3-inch, star-shaped flowers with mahogany-blushed throats have a delightfully clean, sweet fragrance. Four to six blossoms bloom in succession on each 2- to 3-foot stem over a month-long period. In cool climates, lift and store the corms over winter.
Calla (Zantedeschia). Colored callas grow 1 1/2 to 2 feet tall, and they come in exotic colors, as their names ― 'Mango', 'Garnet Glow', 'Flame' ― suggest. The big, white trumpet-shaped flowers of common callas look wonderful when displayed solo in vases. White callas (Z. aethiopica) are nearly evergreen in mild climates but deciduous in cold climates; they grow in Sunset zones 5-6, 8-9, 14-24.
Crocosmia ( Montbretia). Traditional hybrid favorites like 'Lucifer' are big, bold plants ― their sword-shaped leaves make upright fans to 4 feet tall with zigzagging flower spikes. Newer hybrids tend to be smaller ― 2-foot 'Emily MacKenzie', for instance. All flowers are fiery-hued ― reds, oranges, yellows ― and make long-lasting cutting flowers. Plants can naturalize in zones 5-24. Where winter temperatures dip below 10°, give them protective mulch.
Dahlia. Tuberous-rooted plants come in an amazing variety of heights (from 1 foot to taller than 7 feet), flower sizes (from 2 to 12 inches in diameter), and shapes (from tight pompoms to loose cactus types), and every hue but blue. All but the shortest make good cutting flowers; small to medium-size flowers are the most versatile. Dahlias appreciate light afternoon shade in hot summer areas. They can be left in the ground if winter temperatures remain above 20°, but most gardeners lift them each year and replant after the danger of frost is past.
Gladiolus. These are mainstays of the floral industry for good reason ― all varieties create dramatic vertical accents in bouquets. Grandiflora hybrids, also called garden glads, are the largest; individual flowers grow as wide as 8 inches with stems 4 to 5 feet tall. Butterfly glads are shorter (2 to 3 feet) and usually have contrasting blotches of color across the throats (hence the name). Baby glads are shorter still (1 1/2 feet); in zones 4-9 and 12-24, these can be left in the ground for the winter. Most other glads need to be lifted and stored at the end of the growing season. (If your soil is sandy, set tall gladiolus several inches deeper than shown on chart.)
Liatris (Gayfeather). This tough, tuberous-rooted perennial, often sold as a bulb, endures cold, heat, drought, and poor soil. Foxtail-like spikes of rosy purple or pure white flowers emerge from grassy clumps of foliage. At 2 to 4 feet tall, they make good fillers for bouquets. They'll attract butterflies to the garden. Zones 1-10, 14-24.
Lily. There are many species and eight divisions of hybrids, but let's make it simple: Asiatic hybrids are the earliest to bloom. Oriental hybrids come later. Both types happen to be terrific cutting flowers. Lilies have large, trumpet-shaped blooms on strong, tall (up to 5-foot) stems. They grow in a wide variety of colors, often with contrasting throats, speckles, or "brushstrokes." They need ample moisture and prefer filtered sun or afternoon shade in most regions; the root zones like to stay cool. Hardy to -30°.
Tuberose (Polianthes tuberosa). Intensely fragrant, waxy white blossoms emerge on stems as tall as 3 feet above grassy basal foliage and tuberous roots. Both single- and double-flowered forms are very long-lasting. Tuberoses need a long (four-month or longer) warm period before flowering; if you have a short summer season, start them indoors in pots. The scent alone makes tuberoses worth the extra effort. Zones 15-17, 22-24 (in zones 8-9 and 14, plant in pots and move to a protected place for winter).