1 of 30 Amaranthus

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 transplanting well.

2 of 30 Canna Lilies

Try planting these tropical-looking blooms for lush foliage and color later in the season. "Although these flowers do not bloom until the summer, spring planting will give them time to establish themselves and yield intense blooms," says Missy Henriksen, a spokeswoman for the . They're annuals in cool regions and perennials in warmer ones, she adds.

4 of 30 Lily of the Nile

Also called blue lily or African lily, Agapanthus praecox is a full sun or partial shade flower that thrives in warmer areas, especially in pots. "When it comes to containers and hanging baskets that are showing signs of stress, the best thing you can do is to move them into the shade and check often for dryness," advises Kate Karam, editorial director at . "They may need a deep drink at least once or even twice a day."

5 of 30 Wheat Celosia

6 of 30 Garden Cosmos

7 of 30 Sulfur Cosmos

This full-sun annual comes in happy hues including scarlet, orange, and yellow. It's easy to grow from seed in poorer soils and often self-sows, meaning less work for you next year. Expect stalks to grow 1 to 4 feet high.

8 of 30 California Poppies

Eschscholzia californica grows from 6 to 15 inches and comes in red, pink, orange, yellow, and cream. This full-sun 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 blooming all season long.

9 of 30 Gazania Hybrids

This bright, beautiful flower grows 6 to 15 inches and you can find it in vibrant colors like red, pink, bronze, orange, and yellow. It's an especially smart choice for sunny, hot, and dry spots (i.e., the parched beds by the patio).

10 of 30 Lantana

12 of 30 Creeping Zinnia

Sanvitalia procumbens is another short perennial, also only growing 4 to 8 inches high. You can find it in orange or bright yellow. It can perform well in partial shade, but does not tolerate poorly drained soil.

13 of 30 Petunias

Petunias grow from 6 to 24 inches tall and you'll find them in pretty much every color under the sun. Deadhead for continuous bloom all season, but do not plant in areas with high humidity or frequent rain.

14 of 30 Mexican Sunflowers

Tithonia rotundifolia grows anywhere from 30 inches to 8 feet tall. Unlike most common sunflowers, it's more shrublike in growth and doesn't tolerate rain or rich soil well. Deadhead periodically for continuous bloom.

15 of 30 Common Zinnias

"A traditional plant for pollinator gardens, zinnias are easy to grow and require full sun," Henriksen says. She recommends using them in borders and container gardens, and using the cut flowers for indoor décor. They can grow anywhere from 4 inches to 4 feet high and comes in almost every color except for blue.

16 of 30 Coneflowers

18 of 30 Astilbe

If you like pink, choose this showy perennial. The fluffy plumes can grow up to 2 feet tall. Since it's a shade lover, try pairing it with or ferns.

19 of 30 Marigolds

20 of 30 Blanket Flowers

Gaillardia looks like a miniature sunset, fading between yellow, orange, red, and sometimes burgundy. They love bright rays, so don't hide them in the shade.

21 of 30 Hydrangeas

From late spring to early autumn, hydrangeas can steal the show in your garden. Try the for striking ruby-black stems and big mophead flowers, Karam recommends. The border shrub flowers blue in acidic soils and pink in alkaline soils. "The flowers age to a vintage cream-splashed green color," she adds.

23 of 30 Sunflowers

Not all Helianthus are created equal. In summer, try SunBelievable Brown Eyed Girl. "This award-winning, multi-branching, heat tolerant, non-invasive annual produces over 1,000 flowers in a single season, throughout summer until first frost," Karam says. Try it in both borders and containers.

24 of 30 Dahlias

Grow the "dinnerplate" kind and the blooms can measure a whopping 12 inches in diameter. On the flipside, miniature "pom-pom" dahlias look just as cute as they sound.

26 of 30 Daisies

Daisies , but the perennials work much harder than their dreamy meaning lets on. Mounds of tall stems bloom for months on end, and almost never fail to reappear next spring.

27 of 30 Coreopsis

Native to the U.S., cheery-looking "tickweed" grows in hardy clumps. Try them in the traditional yellow, or branch out with vibrant pink, red, and bicolor varieties.

28 of 30 Irises

Named after the Greek goddess of rainbows, the iris family also comes in a wide spectrum of colors. Divide the every few years to reinvigorate flowering — and spread the delicately petaled plants across your landscape.