14 Stunning Flowers to Plant in May for a Bloom-Filled Summer

The fifth month is the moment, my brothers and sisters-in-gardening! Time to roll up those sleeves and flex your two times five fingers.

You don’t need numerology to tell you that 14 is the lucky number for the stunning summer superstars I’m about to unveil. Give yourselves a mental high-five, and let’s dig in!

My Quick Tips for May Flower Planting

When you take a look at the member list of our summer bloom fan club, it couldn’t be more diverse. And yet, they all share this fundamental desire for sunshine.

They’re like tiny solar panels that need ample sunlight (at least 6-8 hours of direct sun) to fuel their growth and produce lovely blooms. So choose a sunny location. It translates to more energy for vivid colors and abundant flowers.

During those first few weeks of a settling-in period, your young plants will need consistent hydration to establish strong roots. You should keep the soil consistently moist (but not waterlogged!) until you see new growth. That’s the green light signaling they’re feeling right at home.

And once it starts growing, notice if a plant is reaching tall and a bit sparse. That’s “leggy” growth. Don’t be afraid to give those stems a gentle pinch (remove the top inch, about 2.5 cm). This encourages the plant to branch out, leads to more stems and, you guessed it, more flowers.

14 Flowers to Plant in May for a Bloom-Filled Summer!

And now, prepare to meet our dazzling misses of May.

1: Zinnias

If you didn’t have a glorious opportunity to witness what a box of crayons looks like when it’s let loose, that’s Zinnias. They are easy-going annuals, quite happy across zones 3-10. Direct sow or transplant in May, and in just 6-8 weeks, you’ll witness an explosion of colors. Over your new (green) carpet…

To extend their blooming, you’ll want to deadhead them regularly, take a look at our full guide on how to deadhead zinnias to keep them blooming.

2: Cosmos

Looking for truly stellar blooms? Cosmos is surprisingly unfussy and thrives even in less-than-perfect soil under the full sun. Grow them from seed in zones 3-10 after any threat of frost has passed, and soon you’ll have a universe of delicate, airy flowers.

3: Marigolds

There’s so much magic about Marigolds! They are famous for their timeless beauty (and easy growth). They are protective (against garden pests). Transplant or direct sow these annuals across zones 2 to 11 in May, and brace for the reward. Geralt approves 100%.

4: Nasturtiums

Do not shy away, dyslexic gardeners, from this charming annual!

Nasturtiums kindly prefer to be direct-sown right where they’ll grow. They don’t care about the poor soil. Nor do they complain about living in a pot. They don’t even care much about the zone; everything from 3 to 10 suits them!

Your reward? If you do decide to twist your tongue, eat them instead. Their peppery blooms and leaves add a kick to salads!

5: Petunias

I bet you didn’t have a friend called Petunia. You don’t know what you’re missing. They are easygoing, reliable, and always ready to party, should you plant a few in May.

Thriving as annuals across zones 2-11, and even as perennials in warmer zones 10-11, they’ll keep the good times (and the flowers) rolling all season long.

6: Salvia (Annual varieties)

Save a spot for Salvia. After their May transplant, annual varieties like Salvia splendens do wonderfully in zones 3-10. They’re also heat-tolerant and magnets for bees, butterflies, and hummingbirds.

But leave their leaves out of your teacup. They might have felt an inferiority complex to their cousins with an MD degree, if only they weren’t so bee-utiful.

7: Calendula

Let history remember Calendula as a cool emperor of your garden. It is content across zones 2–9 (mostly as an annual, with a longer life in warmer zones).

Its Flowership is surprisingly quick to establish, blooms quickly, and prefers to be sown in cool spring temps. All praise the benevolent ruler of the spring landscape!

8: Sunflowers

Want one-season tall-stalked giants in your zones three-ten garden? Just groundput sunflower plantstarters outdoors. The quick-growing heat-lovers are also low-maintenance garden cheerleaders. Watch them skyrocket!

9: Coreopsis

Worried about catching a seriously contagious case of yellow… summer cheerfulness? You might just succumb to Coreopsis. Throughout summer, these beauties will produce masses of daisy-like flowers that pollinators adore (treat them as annuals in cooler climates).

In zones 4 through 9, you can plant them from seed or transplant in May and then stay delightfully afflicted well into fall.

10: Coneflowers (Echinacea)

Well, I suppose Echinacea looks a bit like a cone, if you squint. But even if you disagree, trust me, this steadfast perennial will grace your garden in zones 3 through 9.

Get these started in the spring, either by seed or transplant, and expect blooms that are a favorite landing pad for bees and butterflies. A bit cone-shaped pad, I guess.

11: Black-eyed Susans (Rudbeckia)

Someone truly must have been head over heels for a Susan with gorgeous black eyes! And whatever your sweetheart’s name might be, fellow gardener, they’ll surely fall for Rudbeckia.

While often shorter-lived in zone 3, these are generally reliable bloomers from June to August in zones 4 through 9. Your cat might fall for it, too. Literally. Plant and cat parents, it’s best to keep these kids separated.

12: Verbena

Looking for a plant that knows how to make a dramatic entrance (and exit) from your containers and beds? While Verbena graces most gardens (zones 3-9) as a reliable annual, those in warmer regions (zones 8-10) get to enjoy its beauty year after year.

Plant your starts in May and prepare for the ultimate spiller, exuding effortless elegance… wherever it goes.

13: Blanket Flower (Gaillardia)

Alors, you seek a flower that is not just jolie but also tough, oui? Transplant little Gaillardia in late spring, and voilà, they will flourish across zones 3 to 10, magnifique perennials that they are!

They laugh in the face of le chaud (the heat) and la sécheresse (the drought), blooming with such joie de vivre right into the fall.

14: Dianthus

The Dianthus genus is not a gladiator. And yet, if you transplant them or sow them outdoors in May, these hardy contenders will create a beautiful border around your floral arena in the summer.

They’ll delight the audiences across zones 3-9 as annuals or short-lived perennials with a delightful clove-like scent. Let the blooming begin!

Rooting for Your Planting Success This May

As you can see, the great 14 are quite diverse. Still, all these plants are quite forgiving, ideal for beginners.

Most of them are eco-friendly, attracting beneficial insects. Many are adaptable to various garden settings and zones. And when it comes to bringing joy to your garden, they surely leaf no gardener wanting.