Annual plants are plants that last for one growing season before dying off, though some annuals reseed themselves. Annual plants are useful in gardening as they offer the opportunity to try a new look each season and provide quick and lasting color. Annuals may be planted as seeds or purchased at most major retailers in starter packs, or flats, of different sizes depending on the variety. Flats may come in groups of four, six, eight or more.
Sold by the colorful flat-full in garden centers each spring, verbena (Verbena x hybrida) is a half-hardy annual that is heat tolerant and fragrant. Verbena has numerous hybrids--some with contrasting white centers-- and comes in red, white, violet, purple, blue, cream, rose or pink. The plants grow 1 to 2 feet tall and have a spread of about 1 foot. Verbenas enjoy full sun and should be planted in well-draining, rich soil. The plants are useful as ground cover, border edging, containers and window boxes. They grow well in any zone and are considered perennial in zones 9 to 11.
Also known as flowering cabbage or ornamental kale, ornamental cabbage (Brassica oleracea) is a fast-growing, low plant that adds a unique burst of color to a garden. These plants, which grow to about 1-1/2 feet, have large, green lettuce-like leaves that open to a show colorful (white or red) center. Hardy in any zone, ornamental cabbage is a particularly good choice for a Northern garden, where it is generally sold as a fall bedding plant, as it does well in cool temperatures. Plant in full sun, well-draining, neutral soil and water regularly.
There are several varieties of sage (Salvia), including annual sage (Salvia horminum) native scarlet sage (Salvia coccinea) and scarlet sage (Salvia splendens), that are specifically annuals. These plants flower from summer to fall and thrive in full sun and well-drained soil. Scarlet sage, the most well-known, grows to 2 1/2 feet and grows upright with little spread. Flower spikes may be red, white, pink, violet or deep purple. Hardy in any zone, plant in neutral soil and keep moist.