Ageratum
Clusters of small, fluffy blooms in white, blue, or lavender appear on ageratum from early summer through fall. Varieties range in height from 6 to 30 inches tall. Taller varieties make the best annual cut flowers because you can cut the stems to the height you want in your vase. This annual also grows well in containers and benefits from regular doses of general-purpose fertilizer ($10, Home Depot).
Growing Conditions: Full sun to part shade in moist, well-drained soil
Size: Up to 30 inches tall
Buy It: Ageratum Flower ($12, Walmart)
Calendula
Excellent for both containers and beds and borders, calendula is an easy-to-grow, classic annual that produces 2- to 4-inch-wide, daisylike flowers on sturdy branched stems. Calendula does best in cool conditions and will have even more flowers if you deadhead the plant regularly.
Growing Conditions: Full sun to part shade in moist, well-drained soil
Size: Up to 2 feet tall
Bachelor's Button
An old-fashioned favorite annual in cottage gardens, bachelor's button is easy to grow and adaptable, producing beautiful, frilly, single, semidouble, and double blooms in white, blue, pink, or purple. Blooming in early summer to midsummer and intermittently to early frost, it's excellent for cutting and drying.
Growing Conditions: Full sun to part shade in moist, well-drained soil
Size: Up to 2 feet tall
Buy It: Dwarf Blue Bachelor Button Cornflower Garden Flower Seeds ($3, Walmart)
Larkspur
Larkspur, featuring tall stems of spurred flowers, is an annual cousin of the magnificent perennial delphinium. The blue, white, lilac, pink, or peach flowers have a light scent and are held above a mass of lacy, dark green foliage. They're a wonderful annual for cut flowers, and their height makes them a good choice for the back of a garden or along fences and walls.
Growing Conditions: Full sun to part shade in moist, well-drained soil
Size: Up to 4 feet tall
Pinks
The genus Dianthus includes annual and perennial plants, grown for their pink, white, or red spicy, fragrant flowers and their often-evergreen clumps or mats of gray-blue, grassy leaves. Taller annual varieties such as 'Ideal Violet' are excellent for cutting.
Growing Conditions: Full sun to part shade in moist, well-drained soil
Size: Up to 12 inches tall
Buy It: Dianthus Everlast ($8, Walmart)
Gladiolus
These tender bulbs are planted starting in spring, then every few weeks to ensure continuous bloom. An elegant plant, gladiolus produces tall spikes crowded with ruffled flowers facing the same direction and opening from the bottom of the stem. In cold climates, the bulbs (technically called corms) must be dug up and stored in a cool location that will not freeze.
Growing Conditions: Full sun in moist, well-drained soil
Size: Up to 6 feet tall
Buy It: Deluxe Dutch Gladiolus Mixture ($20, Breck's)
Sunflower
Annual sunflowers are a cheerful must-have annual. This native plant is grown for its beautiful flowers and edible seeds. While the most recognizable sunflower has a ring of golden yellow petals around a huge brown center on a very tall stalk, many more subtle varieties have been developed that vary in both size and color, including white, orange, and deep red.
Growing Conditions: Full sun in moist, well-drained soil
Size: Up to 7 feet tall
Buy It: Sunflower Sunny Hedge Blend Seeds ($10, The Home Depot)
Sweet Pea
Prized for their pretty, intensely fragrant flowers, most sweet peas are grown as cool-season annual vines, reaching 4 to 6 feet tall, but some are bushy 1- to 3-foot-tall dwarfs. All produce lovely clusters of 1-inch long, pea-type flowers in white, light orange, yellow, lavender, blue, red, and purple; some produce bicolor flowers. Longer-stemmed types are classic annual cut flowers.
Growing Conditions: Full sun in moist, well-drained soil
Size: Up to 6 feet tall
Stock
A garden cool-season annual that produces blooms with a robust and sweet-and-spicy scent, stock makes an excellent annual cut flower. Double flower types form solid spires of blossoms, while single forms are wispy. The tall column types are usually available only as cut flowers from florists and need five months of temperatures below 65°F. Dwarf types grow just 8 to 15 inches and are more heat-tolerant.
Growing Conditions: Full sun to part shade in moist, well-drained soil
Size: Up to 3 feet tall
Zinnia
A snap to start from seed and not fussy about growing conditions, zinnias have been a garden favorite for generations. Their bright colors work perfectly for creating cheerful, late-summer bouquets.
Growing Conditions: Full sun in moist, well-drained soil
Size: Up to 4 feet tall
Buy It: Zinnia Flowering Seed Mixture ($9, The Home Depot)