18 Summer Flowers That Can Take The Heat

Planting heat-tolerant annuals ensures that your full-sun beds bloom all season long.

July 27, 2016
Christa Neu

If your perennial garden starts to fizzle as soon as hot weather arrives, then you need a plan to keep your beds blooming. Try interplanting your perennials with annuals that love hot weather. All need full sun to flower well, and keep in mind that some of these plants can be aggressive self-sowers or may be listed as invasive in warmer regions. You can experiment each season until you find combinations that best suit you, your garden, and your climate. (Transform the ordinary into the extraordinary with Rodale's The Perennial Matchmaker, your foolproof one-plant-at-a-time approach to picking perfect plant partners and growing your most stunning garden ever!)

Related: Your Guide To The Most Fragrant Flowers

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Also known as amaranth, this flower can grow from 18 inches to 6 feet tall in a variety of colors including red, orange, gold, green, and purple. This direct-sow annual does not tolerate wet soil, shade, or transplating well. 

celosia spicata
Rodale Images
Celosia Spicata

This wheat celosia can grow from 2 to 4 feet and in red, pink, or purple. This annual makes for a great cut flower arrangement—either fresh or dried—and cannot tolerate cold soil and water. 

Related: 3 Ways To Make Cut Flowers Last Longer

cleome hassleriana
Christa Neu
Cleome Hassleriana

The spider flower grows to be about 3 to 5 feet in rose, pink, purple, and white. It's easy to grow from seed and self-sows for future seasons. 

cosmos bipinnatus
Thomas MacDonald
Cosmos Bipinnatus

This perennial grows to 2 to 5 feet in crimson, pink, and white. Like the Cleome Hassleriana, the Cosmos Bipinnatus is easy to grow from seed and often self-sows. However, it cannot tolerate rich soil, as it will yield few flowers. 

cosmos sulphureus
Cosmos Sulphureus

This annual can grow 1 to 4 feet and in warm colors including scarlet, orange, and yellow. It's easy to grow from seed and often self-sows, except in rich soil—where is will yield very few flowers. 

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Eschscholzia Californica

Better known as the California Poppy, the Eschscholzia Californica grows from 6 to 15 inches and in red, pink, orange, yellow, and cream. This perennial grows best if directly sown—as it doesn't tolerate transplanting well. It also doesn't thrive in rich or wet soil. Deadhead periodically for continuous bloom. 

Related: The 8 Prettiest Places In The World To See Flowers In Full Bloom

gazania hybrid
Rodale Images
Gazania Hybrids

This bright, beautiful flower grows 6 to 15 inches and in vibrant colors like red, pink, bronze, orange, and yellow. It is especially good for hot and windy spots, but doesn't tolerate rain, wet soil, or humidity.

cypress vine
Mitch Mandel
Ipomoea Quamoclit

The cypress vine grows from 6 to 25 feet in a beautiful scarlet color. Although it's a tough perennial that thrives well in all soils, it does not do well as a transplant. It's easy to grow from seed and often self-sows for future seasons.

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This annual grows from 1 to 6 feet and in a variety of colors including red, pink, orange, cream, lilac, purple, white, and bi-colors. You can buy transplants, but don't plant them in rich soil or in areas where night temperatures dip below 60°F. Keep in mind that the berries of this flower are toxic—so look for nonfruiting varieties. 


Robert Cardillo

Better known as flowering tobacco, this annual grows from 8 inches to 5 feet and in rose, pink, green, purple, and white. It's easy to grow from seed, but you must water at the base of the flower as wet stems and leaves can cause problems. Some species of this flower are fragrant and some will self-sow. 

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Petunias grow from 6 to 24 inches and in all colors. Deadhead for continuous bloom all season, but do not plant in areas with high humidity or frequent rain. 

Related: 9 Flowers That Add Color To Your Garden


Pintip Kasemsarn/Shutterstock

Rose moss is a petite perennial—growing from 4 to 8 inches—and in colors including red, magenta, pink, salmon, orange, yellow, and white. It's easy to grow from seed, but does not tolerate high humidity well. 

creeping zinnia
Sanvitalia Procumbens

The creeping zinnia, like the Portulaca, is a petite perennial, also only growing 4 to 8 inches. You can find it in orange or bright yellow. It can perform well in partial shade, but does not tolerate poorly drained soil. 

Related: 51 Plants That Don't Need A Lot Of Sun To Thrive


These marigolds can grow from 6 inches to 4 feet and in a variety of warm autumn colors including maroon, orange, yellow, and cream. It's easy to start from seed but does not grow well in rich soil. Deadhead for continuous bloom. 

mexican sunflower
aoy jira/Shutterstock
Tithonia Rotundifolia

The Mexican sunflower grows from 30 inches to 8 feet in orange or yellow. Unlike most common sunflowers, the Tithonia Rotundifolia is shrublike in growth and doesn't tolerate rain or rich soil well. Deadhead periodically for continuous bloom. 

Related: 10 Insects You Should Actually Want Around Your Plants

verbena peruviana
Robert Cardillo
Verbena Peruviana

The Peruvian Verbena is a tiny annual—growing 3 to 6 inches—and in red, pink, and white. It's good as groundcover and grows well on sloped land. It also performs well in partial shade, but does not in wet soil. 

moss verbena
Verbena Tenuisecta

The moss verbena is a bit larger than its Peruvian counterpart—growing 8 to 12 inches—and in pink, lavender, purple, and white. It does not grow well in poorly drained soil. 

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Christa Neu
Zinnia Elegans

The zinnia flower can grow from 4 inches to 4 feet and in all colors, except for blue. It's easy to grow from seed, but does not tolerate wet soil or poor air circulation well. Deadhead for continuous bloom all season. 

Related: Secrets To Growing Bright, Beautiful Zinnias