Top Flowers to Plant in May for Color That Lasts All Summer

As the weather warms up and the risk of frost fades, May is the perfect time to fill your garden with long-lasting blooms that will bring vibrant colour right through the summer months. Whether you’re working with garden beds, pots, or hanging baskets, here are our top picks for flowers that thrive when planted in May and put on a show all season long.

1. Geraniums

Geraniums are a classic summer staple — and for good reason! They thrive in sunny spots, bloom continuously with minimal care, and come in a rainbow of bold shades. Choose zonal or trailing varieties depending on whether you're planting in beds or baskets.

Tip: Deadhead regularly to encourage more blooms.

2. Marigolds

Easy to grow, cheerful, and pollinator-friendly, marigolds are perfect for borders and containers. French and African varieties both love the sun and bloom profusely right into autumn.

Bonus: Marigolds are known to help deter pests in vegetable gardens!

3. Petunias

Petunias are one of the most reliable annuals for non-stop colour. Available in every hue imaginable — even black! — they’re ideal for hanging baskets and window boxes.

Try this: Mix bold colours with trailing varieties for a lush, overflowing display.

4. Cosmos

These airy, elegant flowers are perfect for adding movement and charm to your garden. Sow seeds or young plants now and enjoy a sea of soft pinks, whites, and purples well into September.

Perfect for: Cottage gardens, pollinator plots, or cut flower beds.

5. Salvia

These upright, spiky blooms add texture and height to your beds. Salvias are drought-tolerant once established and attract bees and butterflies throughout summer.

Favourites: Try 'Caradonna' or 'Hot Lips' for striking contrast.

6. Dahlias

Plant dahlia tubers now for stunning blooms by midsummer. From pom-pom styles to dinner-plate giants, dahlias offer dramatic color and shape. They love rich soil and a sunny position.

Keep in mind: Dahlias aren’t frost-hardy, so lift the tubers in autumn for storage.

7. Sunflowers (Dwarf or Giant)

Sow sunflower seeds in May and enjoy their golden cheer through the summer. Go bold with towering giants or opt for compact dwarf types for containers.

Fun project: Great for kids and beginner gardeners!

8. Begonias

Ideal for shadier spots, begonias offer bright, tropical-looking blooms that last all summer. Choose upright or trailing varieties depending on your display.

Low-maintenance: Great for busy gardeners or low-light patios.

Final Tips:

• Water new plants well, especially in warm weather.

• Feed flowering plants every 2–4 weeks to keep the blooms coming.

• Mix heights, colors, and textures for the most eye-catching displays.

 

Ready to plant? Visit us at Flowerland to browse our full selection of summer bloomers and chat with our friendly team for expert planting advice. Let’s make your garden burst with colou r all season long!