Although many gardeners groan when they hear the childish phrase “April showers bring May flowers,” there’s truth in that May is a month of planting. 

The days are no longer cold and dreary, and the rains have stopped their relentless onslaught. It’s sometimes surprising how quickly young plants send up shoots, transforming an unseemly patch of land into a lively, colorful haven come summertime. 

Here’s a list of several fast-growing annuals that ensures that your garden will be bursting with color in no time. 

1. Marigold 

Marigolds are one of these flowers that truck on full sprint into the summer months, with blooms that burst forth like pom-poms. These hardy flowers can thrive in most types of soil and will bloom prolifically from May to August. In the realm of companion planting, they also act as natural pest-repellents, which is why many gardeners choose to intersperse them among their garden crops. 

2. Sweet Alyssum 

Not many take note of the intoxicating, honey-like fragrance of sweet alyssum until it’s right under their noses. Sweet alyssum is an understated flower that thrives in a wide range of soil types; the ‘Stream’ series blooms all summer long regardless of the heat. Sow in spring before the intense temperatures set in. Its flowers grow close to ground, and they are frequently used as filler plants in containers, underscoring more vibrant bloomers. 

3. Snapdragons      

Snapdragons are a quick way to add ruffled texture to a garden. Their tall stalks, bursting with blossoms, make them ideal candidates for flowering borders. They’re also planted in expanses, often meshing with flowers like marigolds, to create a summer idyll. Although they’re often considered annuals, snapdragons can be grown as short-lived annuals in zones 7-10. A mixed bed of snapdragons will yield multiple different colors, allowing for a beautiful, ombre-effect. Some varieties are large and long-stemmed, in contrast to others that are bushier and more compact. 

4. Morning Glory  

Morning glories do not live in fear of blooming – within a couple of months, they will swarm any available space with an abundance of trumpet-like blooms. In some areas, it is a vigorous grower, sometimes too vigorous. If you’re worried about their aggressiveness, planting them in raised beds with trellises can help curtail their spread. 

5. Sunflowers     

With sunflowers, your garden will never be lonely. Many are familiar with the ever-present yellow, but sunflowers can come in shades of cream, bronze, pale yellow, and even ochre-pink. Sunflower 'Giant Sungold' is a lovable variety that bears giant, teddy-bear orbs perfect for borders or in beds. Single-stem sunflowers will grow quicker, but branching types last weeks longer. For continuous blooms, plant in succession every 2 to 3 weeks throughout the growing season. When the seeds start to ripen, they will attract a slew of birds. 

6. Bachelor’s Button

Bachelor’s button, also known as cornflower, produces a legion of frilly, profusion of flowers. Beyond the classic blue, they are available in shades of pink, ruby red, and dark purple. Cornflowers are usually sown during spring or fall and bloom for about 10 weeks, persisting for longer in milder climates. Their tendency to spring up whenever they are scattered make them excellent for chaos gardens. Many newer varieties will bloom throughout the summer if regularly deadheaded. 

7. Gladiolus

No longer an old-fashioned choice, the gladiolus is the life of the garden party, with showy cultivars like 'Jester' and 'Fidelo' on the market. Keep them well-watered but not soggy, and you’ll be rewarded with a vibrant display. Due to their height, many benefit from staking; otherwise, they can flop over and fail to bloom. Simply place them against a fence or trellis, then secure with fishing line, jute or garden twine.

8. Dahlia       

Grown from tubers, dahlias are relatively easy to grow, rapidly filling a stretch of land with their sculptural forms in every color imaginable. Indeed, some gardeners have devoted entire areas of their gardens to growing dahlias, which look good in any garden theme. Dig up tubers after the first frost, once the foliage has withered and turned brown. 

9. Petunia        

Petunias have a reputation of being boring and basic, but that is only because gardeners haven’t branched out. Nowadays, petunias are available in a wide range of colors, from hot, vibrant shades to the color of the night sky. They’re also easy maintenance and can be readily found in garden centers; plant in full sun to prevent them from becoming spindly. 

10. Zinnias        

Some of the key attributes of zinnias are that they are among the easiest to grow from seed and are highly attractive to pollinators. Zinnias thrive on neglect – they’re one of these plants that grow even if you ignore prudent gardening advice. Another summer staple, they pair well with other flowers like cosmos, alyssum, and marigolds. 

11. Firecracker Plant   

Able to withstand arid heat, firecracker plants are perfect candidates for desert gardens. Their abundance of tubular flowers is pollinator friendly. During periods of extended drought, they explode from their habitats, as if raining fiery comets of flowers. They also thrive in pots in conjunction with partial shade.

12. Cosmos 

Cosmos are delicate flowers popular in cottage gardens. When grown with other airy flowers like sea holly, cosmos create a striking, billowy effect. They will happily grow in average soil, preferring drier, arid soil over soggy conditions. Gardeners either plant indoors or sow directly in the ground in May. Cosmos will readily reseed, giving your garden beds new plants the next year.