11 Best Annuals for Sun to Add Color in the Heat of Summer

Angelonia

Don't let angelonia's delicate-looking flower spikes fool you. It's one of the best container plants in hot, sunny locations. Throughout the growing season, angelonia produces hundreds of purple, pink, or white flowers that are a favorite of butterflies and hummingbirds. This plant also goes by the common name of summer snapdragon because of the shape of the blossoms (though it's unrelated).

'Archangel' series plants (such as the purple variety shown here) grow 14 inches tall and wide, making them perfect for most containers. The 'Angelface' series has a cascading habit; try it in hanging baskets or over the edge of a container.

Growing Conditions: Full sun and well-drained soil

Size: 1 to 2 feet tall and wide

Celosia

Blooming in nearly every color of the rainbow, celosia boasts feathery plumes of flowers (some varieties can produce wavy, crinkled flower heads that are especially fun to grow). They make long-lasting cut and dried flowers, but any blooms you leave in the garden are sure to draw all sorts of pollinators, especially bumblebees. Some celosia varieties can get quite large, so place them where they'll have room to expand.

These eye-catching, easy-care annuals for sun come in many stunning varieties, such as 'Dragon's Breath', which has bright red plumes and purple-flushed foliage, and 'Century Mix', which gives the garden a tropical feel by blooming in shades of yellow, red, orange, or magenta.

Growing Conditions: Full sun and well-drained soil

Size: 1 to 3 feet tall and wide

Garden Cosmos

Ferny foliage paired with refreshing shell pink, white, or magenta flowers makes garden cosmos a must-have for cottage gardens. Easy to grow from seeds planted in late spring, cosmos begin blooming in midsummer and keep going until frost. Snip armloads of stems for bouquets, and the plants will reward you with even more flowers in just a couple of weeks. Cosmos occasionally need staking to remain upright. 'Sensation Mix' is an heirloom variety with bright, clear-colored flowers; 'Sea Shells' has rolled flower petals.

Growing Conditions: Full sun and well-drained soil

Size: 2 to 4 feet tall and 2 to 3 feet wide

Geranium

Flowering through heat, dry spells, and occasional neglect, geraniums (Pelargonium spp.) are annuals for sun that have what it takes to make it through a long, hot summer. Cultivars flower in all shades of red and pink, as well as bright white and orange. New cultivars combine the best of common Zonal geraniums with trailing ivy geraniums. The result is new hybrids that flower prolifically and boast vibrantly colored flowers. Look for the upright and clump-forming 'Calliope' series and trailing 'Caliente' series.

Fertilize plants with an all-purpose fertilizer every two to four weeks, and deadhead faded blooms weekly to encourage more flowers to develop.

Growing Conditions: Full sun and well-drained soil

Size: 1 foot tall and 1 to 2 feet wide

Lantana

A butterfly and hummingbird magnet, lantana pumps out nectar-rich clusters of flowers in shades of yellow, orange, white, red, and pink. This drought/heat-tolerant annual begins blooming in early summer and goes until frost. In warm winter climates, lantana is actually a shrubby perennial plant, but in areas where it freezes, it's grown as an annual. The 'Luscious' series is prized for its prolific flower production. 'Lucky Red' has striking red-yellow flower clusters and tolerates humidity easily.

Growing Conditions: Full sun and well-drained soil

Size: 1 foot tall and 1 to 3 feet wide (as an annual)

Marigold

Light up garden beds and containers with bright, sunny marigolds. A cinch to start from seed and easy to find as transplants at garden centers, marigolds produce cheery, pompom-shaped flowers in shades of yellow, orange, and red from early summer until frost.

Grow compact French marigolds near the front of a border or in a container. Taller African marigold works well in the middle of a garden display. 'Big Duck' hybrids are exceptionally long-blooming African marigolds. 'Hot Pak' series of French marigolds have excellent heat and humidity tolerance. Their scented foliage makes marigolds deer-resistant, too.

Growing Conditions: Full sun and well-drained soil

Size: 6 inches to 3 feet tall, 6 inches to 2 feet wide

Mealycup Sage

Wands of purple flowers decorate mealycup sage (Salvia farinacea) from early summer until frost. Easiest to start from transplants purchased at the garden center, this beautiful annual salvia grows fast, standing 1 to 2 feet tall and wide by midseason. Count on it for providing vertical accents in a garden bed or pair it with trailing plants in a container. Snip off the spent flowers in July, and the plant will quickly produce another round of flower spikes. 'Evolution' and 'Victoria' are two cultivars prized for their rich purple blossoms.

Growing Conditions: Full sun and well-drained soil

Size: 1 to 2 feet tall and wide

Pentas

Reliably blooming all summer, pentas has large clusters of star-shaped flowers in shades of white, pink, and red, which provide a nectar buffet for pollinators. Very tolerant of heat and humidity, pentas is an annual for sun that works well as filler in containers, or you can group several plants in a garden bed for a big splash of color. Most varieties stay under two feet tall, but 'Sunstar' series plants are nearly that tall and about as wide when fully grown, so just one could fill out a container by itself.

Growing Conditions: Full sun and moist, well-drained soil

Size: 1 to 2 feet tall and wide

Petunia

Petunias have some serious flower power and can make a carpet of blooms in a garden bed or cascade over the edge of a container or hanging basket. Trumpet-shaped blossoms in shades of white, pink, red, purple, or yellow decorate the plant's trailing stems from early summer until the first frost. Petunias flower best when given an all-purpose fertilizer every month or so. If plants become gangly, cut stems back by one-third their length to encourage dense growth and new flowers.

The 'Wave' series is prized for spreading 4 feet or more. The 'Supertunia' series includes many bicolor varieties, such as 'Raspberry Blast' shown here.

Growing Conditions: Full sun and well-drained soil

Size: 6 inches to 1 foot tall and 1 to 4 feet wide

Annual Vinca

Glossy green foliage is the perfect backdrop for annual vinca's pinwheel-shaped flowers in shades of pink, lavender, red, and white. This tough plant blooms from early summer until frost without missing a beat, flowering best in full sun (but it can take a little shade, too). Vinca is a wonderful annual for sun since it's exceptionally heat tolerant and forgiving in times of drought. You can find upright-growing varieties as well as trailing varieties. For example, the 'Cora' vinca series features many colors and upright and trailing varieties.

Growing Conditions: Full sun to part shade and well-drained soil

Size: 1 foot tall and 1 to 2 feet wide

Zinnia

Easy to start from seed, zinnias produce armloads of daisy-like flowers from midsummer until fall. Zinnia flowers come in nearly every shade and range in size from petite 2-inch blossoms to 6-inch-wide showstoppers. Plant zinnia seeds directly in the garden after the chance of frost passes. 'State Fair' mix produces big flowers on long stems. 'Thumbelina' grows just 6 to 10 inches tall; try it along a walkway as a colorful edging plant.

Growing Conditions: Full sun and well-drained soil

Size: 6 inches to 3 feet tall and 1 to 3 feet wide