The 10 Best Spring Annuals to Plant in Window Boxes

Window box with snapdragons, pansies, alyssum — Credit:
Getty Images

Window boxes filled with flowers and foliage plants are a wonderful way to enhance your home's curb appeal. With spring in full swing, it's time to choose which plants you want to grow in these containers for the season. Typically, annuals are best for growing in window boxes, as they offer beautiful color and are easy to swap out once they finish blooming. To help guide your planting choices, we're sharing the best spring annuals to grow in window boxes, from colorful flowers to long-lasting foliage plants.

Patrick Greenwald, senior horticulturist at Longwood Gardens, a botanical garden in Kennett Square, Pennsylvania
Justin Hancock, horticulturist for Costa Farms, a grower of more than 1,500 plant varieties on 5,200 acres
Andrew Bunting, vice president of horticulture at the Pennsylvania Horticulture Society

01 of 10

Pansies

Pansies (viola x wittrockiana) are early spring bloomers that make excellent accents to window boxes. "Very frost-tolerant, these are some of the first flowers that can be planted outdoors in spring," says Patrick Greenwald, senior horticulturist at Longwood Gardens. "Typically staying under a foot tall and wide at maturity, new varieties have been bred to trail out of the side of a basket or window box, making them even more perfect for a spring display." The flowers continue to bloom until summer.

Zones: 6 to 10
Size: 4 to 9 inches tall x 9 to 12 inches wide
Care requirements: Full sun; average-to-moist, well-drained soils

02 of 10

Sweet Alyssum

Like pansies, sweet alyssum (Lobularia maritima) is a frost-tolerant annual great for spring containers. "Their sweetly scented cheerful flowers range in color from white to rose pink to violet, filling in nicely around taller spring annual flowers," says Greenwald.

Zones: 6 to 10
Size: 3 to 10 inches tall x 2 to 4 inches wide
Care requirements: Full sun to partial shade; well-drained soils

03 of 10

Dusty Miller

Dusty miller (Senecio maritima) has striking silver-gray foliage that adds interest to any container display. "If added to a spring window box display, they can be left all summer long," says Greenwald. Dusty miller is also drought-tolerant once established, which is ideal considering that window boxes dry out quickly.

Zones: 9 to 12
Size: 1 to 2 feet tall x 1 to 2 feet wide
Care requirements: Full sun to partial shade; well-drained soils

04 of 10

African Daisy

Close-Up Of Pink and Red Daisy Flowers — Credit:
Isabel Pavia / Getty Images

African daisies (Osteospermum) add a whimsical, cheerful aesthetic to window boxes. "Osteospermum grow best in the cool weather of spring," says Greenwald. "Best planted after the last frost, these daisy-like flowers range in height, but during the annual spring season usually are around 12 inches tall and wide." They come in various hues, ranging from pinkish-purple to yellow and white.

Zones: 9 to 11
Size: 1 to 3 feet tall x 1 to 2 feet wide
Care requirements: Full sun; well-drained soils

05 of 10

Dianthus

Dianthus (Dianthus spp.) is a large genus of flowering plants, including several annual varieties ideal for window boxes. "Dianthus is a mounding plant with clusters of colorful—and almost always fragrant—pink, red, purple, or white flowers," says Justin Hancock, horticulturist for Costa Farms. "Annual dianthus varieties can grow in any zone, but most don’t love hot summer weather, so once heat and humidity set in, you may see them start to sulk."

Zones: 3 to 9
Size: 6 to 18 inches tall x 12 to 18 inches wide
Care requirements: Full sun; well-drained soil

06 of 10

Juncus

Juncus (Juncus effusus) is technically a perennial, but it's often grown as an annual in cooler climates during spring. "It’s such a wonderful choice for adding texture to spring window boxes," says Hancock. "The grassy-like leaves have a blue-green color that blends well with just about any color scheme, and their thin texture adds upright verticality."

Zones: 5 to 9
Size: 2 to 3 feet tall x 12 inches wide
Care requirements: Full sun to partial shade; well-drained soil

07 of 10

Snapdragon

Snapdragons (Antirrhinum) are a tried-and-true spring annual that produce intricate flowers on a spike, says Hancock. "It’s earned its common name because, with a little imagination, each individual flower can look like the face of a dragon," he says. "Some varieties have a sweet fragrance, so they’re both beautiful to the eyes and the nose." Like the other flowers on this list, snapdragons are available in a range of colors, including reds, yellows, oranges, pinks, purples, and white.

Zones: 7 to 10
Size: 1 to 3 feet tall x 6 to 12 inches wide
Care requirements: Full sun; well-drained soil

08 of 10

Violas

purple viola flowers — Credit: Mimi Ditchie Photography/Getty

Violas (Viola spp.) look like pansies, but they're smaller in size. The flowers come in a myriad of colors, including white, blue, purple, yellow, and pink, says Andrew Bunting, vice president of horticulture at the Pennsylvania Horticulture Society. A great addition to window boxes, violas are tolerant of cool conditions.

Zones: 5 to 9
Size: 3 to 4 inches tall x 3 to 4 inches wide
Care requirements: Full sun to partial shade; moist, well-drained soil

09 of 10

Nemesia

Nemesia (Nemesia spp.) boasts two-lipped, often bicolor flowers in shades of white, yellow, red, orange, pink, or purple. "This bunching and branching small annual is great for filling out a window box," says Bunting. "They produce a profusion of flowers and will last in cool climates for several months."

Zones: 6 to 9
Size: 4 to 6 inches tall x 4 to 6 inches wide
Care requirements: Full sun; well-drained soil

10 of 10

Twinspur

Twinspur (Diascia) produces small cup-like tubular flowers in soft pinks and oranges, says Bunting. "The plant is quick to establish itself and fill out every void in a window box," he adds.