10 Fast-Growing Annuals That Will Fill Your Garden With Color in a Flash

Zinnia

Zinnias are an easy-to-grow flower that looks beautiful in almost any yard. Not only do they put on a colorful show, but they're also edible and can be used as a garnish for culinary creations.

"This is a cut-and-come-again flower that's great for bouquets, edible creations, and attracting pollinators," says Mariah Henry, director of sustainable food systems at Carolina Farm Trust. "I love growing zinnias—they're easy to harvest, and come in a variety of colors and sizes."

Linda Langelo, a horticulture specialist at Colorado State University, agrees, adding that zinnias are heat and drought-tolerant, and require minimal maintenance, so they're a good choice for beginner gardeners.

• Zones: 3 to 10
• Care Requirements: 12 to 36 inches tall x 8 to 10 inches wide
• Size: Full sun; well-draining soil
  
• Time to Maturity: 60 to 90 days

Snapdragon

Snapdragons are highly versatile, with varieties available in a wide range of colors and heights. "I love them because they reseed in the garden and spread themselves around," says Langelo. "I've grown them in containers—they flower well in spring and fall and sporadically in the summer."

Justin Hancock, horticulturist at Costa Farms, also notes that it's a relatively beginner-friendly plant. "Just keep it watered and give it a sunny spot, and that's pretty much all you need," he says.

• Zones: 7 to 11
• Care Requirements: Full sun; well-draining soil rich in organic matter
  
• Size: 1 to 3 feet tall x 6 to 18 inches wide
• Time to Maturity: 8 to 12 weeks

Cosmos

Langelo loves cosmos for their "airy, graceful nature," and because their bright colors make for great cut flowers. It's also beneficial for pollinators, and drought tolerant.

"It blooms nonstop from spring to frost," adds Hancock. "It’s also a great self seeder. Even now, in Miami, I like to grow it in my early-spring garden."

• Zones: 2 to 11
• Care Requirements: Full sun, well-draining soil
• Size: 1 to 6 feet tall x 1 to 3 feet wide
• Time to Maturity: About 2 months

Okra

Okra is a delicious vegetable that grows quickly and adds a bit of color to the garden with its yellow flowers. "I like to plant them in rows and mix green and red okra plants," says Henry. "Once it's grown, it creates a beautiful canopy for shorter gardeners like me."

Henry does warn, however, that okra can cause itchiness, so wear long sleeves and a hat when harvesting them. And don't forget to keep a pocket available for snacking!

• Zones: 4 to 11
• Care Requirements: Full sun, well-draining soil
  
• Size: 6 to 10 feet tall
• Time to Maturity: About 60 days

Basil

Basil is a versatile herb that can be used in a wide range of dishes, and it's very forgiving for first-time gardeners. Henry recommends growing different varieties, like Thai basil, Greek basil, and Holy basil.

"There always seems to be an influx of basil at the farmer markets, but there is nothing more satisfying than growing it in your yard!" she says. "Last season I made a cinnamon basil ice cream by infusing fresh leaves in cream before churning."

• Zones: 9 to 11
• Care Requirements: Well-drained soil, full sun, likes containers
• Size: 12 to 24 inches tall x 12 to 24 inches wide
  
• Time to Maturity: 60 to 90 days

Marigolds

Marigolds grow in almost every type of soil, according to Langelo, so they can flourish in a range of environments. You can also choose between different sizes, from medium to large, depending on how much real estate you have–or how much color you want in your garden.

• Zones: 2 to 11
• Care Requirements: Full sun; well-drained soil
• Size: 6 to 36 inches tall x 6 to 12 inches wide
• Time to Maturity: 45 to 50 days

Sunflowers

Sunflowers are a beloved plant for obvious reasons—their vibrant yellow color is both iconic and show-stopping, and they're wonderful for attracting pollinators. However, they're not always the best neighbors.

"They exude chemicals into the soil that will stunt the growth of other plants," says Langelo. "So, have a special spot for them."

• Zones: 3 to 9
• Care Requirements: Full sun; loam, clay, or sandy soil that is fertile and well-drained
• Size: 3 to 8 feet tall x 1 to 3 feet wide
• Time to Maturity: 70 to 100 days

Larkspur

Larkspur is similar to snapdragon in that it adds a lovely layer of vertical interest to your garden—and a splash of color.

"The foliage has a delicate, almost lacy look, so it gives the garden a nice textural contrast in addition to the upright feel," says Hancock. "And I’ve had good luck with Larkspur self-seeding, so unlike some annuals, you don’t need to replant it every year.

• Zones: 2 to 9
• Care Requirements: Full sun; moist, well-draining soil; regular watering
• Size: 1 to 7 feet tall x 1 to 2 feet wide, depending on the variety
• Time to Maturity: 70 to 80 days

Peppers

There's no shortage of peppers to choose from, from sweet and mild to hotter flavor profiles. Henry notes that they're great for beginners, because you can harvest them according to your preference—when they turn green, or when they're red, orange, or yellow.

"I love peppers and have grown them in every season—and you can nerd out with pruning techniques, trellising, and companion planting," she says.

• Zones: 4 to 11
• Care Requirements: Direct sun, well-drained soil
• Size: 1 to 4 feet tall x 6 to 24 inches wide
• Time to Maturity: 50 days, or less, depending on the variety

Angel's Trumpet

These sculptural plants add both color and drama to the garden with their cup-shaped flowers. It has soft, velvety foliage and is also great for attracting pollinators.

"It's a quick grower that can get 3 feet tall and 4 feet wide, making for a majestic appearance by the end of the summer," says Hancock. "Back when I lived in the Midwest, I’d enjoy evenings on the front porch watching hummingbird moths visit the flowers."

• Zones: 9 to 11
• Care Requirements: Full sun (with afternoon shade in very hot regions); moist, well-draining soil
• Size: 6 to 35 feet tall x 3 to 10 feet wide
• Time to Maturity: 4 to 8 weeks