7 annual flowers to sow in May for summer cutting

Discover a selection of fantastic flower seeds to sow directly into your cutting beds this month

A collection of cut flower blooms laid out on a table
(Image credit: Getty Images/Photos by R A Kearton)

Being able to pick flowers from your own cutting patch to display around the home or gift to family and friends is a joyous thing. Whether you cut from your flower beds and borders or have dedicated cutting beds, there is a wealth of choices when it comes to flowers to grow. 

Sowing your flowers to cut from seed is a simple and budget-friendly way to grow lots of plants and it can give you a wealth of blooms and foliage to cut each year. 

If you are planning a cut flower garden, many glorious and productive fast-growing plants can be sowed in May to give you a plethora of blooms to cut during summer and early fall.

A vase full of cut flowers in mixed colours

(Image credit: Getty Images/Clive Nichols)

Should I sow flowers indoors or outdoors in May?

Many cutting garden flowers can be sown indoors early in the year to get ahead, and also be sown directly into the soil once the frosts have passed and the temperatures increase. 

Utilizing both methods, as a form of succession planting, can help to extend the period of blooms for picking. We look closely at 7 fantastic cutting flowers that can be directly sown this month.

1. Ammi

flowering ammi majus growing in butterfly garden

(Image credit: Steffen Hauser / Botanikfoto / Alamy)

Ammi is a great foliage plant option to add to floral arrangements. With cloud-like white frothy flower heads and fine green foliage, it deserves a spot in any vase.

The plant can be sown in the fall, while you can also get a great display of flowers from a spring sowing in May. Ammi can be sown directly once the soil temperature rises above 60°F in shallow drills 12 inches apart. 

Sowing the annual flower in situ avoids disturbing the taproot that Ammi produces, which can be a risk when transplanting young seedlings sown indoors.

2. Cornflower

cornflowers

(Image credit: Mihaita Costin / 500px / Getty Images)

Cornflowers, often also called Bachelor's Button flowers, have small blooms but the plants come in many colors and sizes. The taller varieties do make good cut flowers as the blooms - which can come in shades of blue, pink, and dark red - can look good in the vase for up to two weeks. 

Sow cornflower seeds directly into the soil and cover them lightly in May - the seeds are only small and do not want to be buried too deep. They can be sown into June, but the plants will be smaller. You can choose from different varieties or get seed packets of mixed colors, like this mix of Bachelor's Button seeds available at True Leaf Market.

3. Cosmos

pink cosmos

(Image credit: Geoff Smith / Alamy Stock Photo)

Cosmos are prolific and gorgeous cut flowers, with soft foliage and attractive flowers that bloom for months and attract pollinators into a space. Taller varieties of cosmos  - such as Cosmos 'Apricotta', available at Burpee - make the best types of cut flowers and you will be able to choose from many different colors to grow. 

The half-hardy annual can be direct sown in May into a sunny spot in the garden. Plant cosmos seeds after the frosts have ended and thinly sow the seeds 2-3 inches apart. Keep the seeds moist and thin the seedlings to 12 inches. 

When growing cosmos, pinching the tips when the plants reach around 12 inches can give you longer stems and more flowers.

4. Phlox

Pink and white phlox flowers

(Image credit: Getty Images/Jacky Parker Photography)

There are many varieties of phlox to grow and the range of colors means there can be a phlox for any garden, while the sturdy stems keep them statuesque in any cut display. 

Annual phlox can be sown outdoors directly into the garden come late spring, once the risk of frost has ended. These plants will flower later than ones started indoors, but will still give a great display come summer. 

The seeds need to be planted near the surface and covered with only a fine layer of soil. Keep them moist and the seeds should germinate nicely in temperatures of 60-65F. Phlox is a fantastic flower to grow if you suffer from hayfever. The '21st Century Mix' of phlox seeds, available at True Leaf Market, is a great option as they can start flowering around 70 days after sowing the seeds. 

5. Scabious

Blue scabious flowers on tall stems

(Image credit: Getty Images/ImageJournal-Photography)

Scabious are adored for their pincushion flower heads that sit on top of thin stems. They do not have the longest vase life but, as well as being fantastic flowers for bees, butterflies, and other pollinators, they are easy to grow and very productive. 

Annual types of scabious are simple plants to grow from seed and can be directly sown into the soil in May, after the last frost. Sow seeds outdoors in a sunny spot and keep the soil moist. The plants should quickly grow and provide a great display of flowers to cut come late summer.

6. Sunflower

Helianthus annuus 'Firecracker'

(Image credit: Deborah Vernon / Alamy Stock Photo)

Sunflowers are easy flowers to grow from seed and come in many colors and sizes. Single-stemmed sunflowers are great options to grow as cut flowers and can be sown indoors or outdoors in May. 

You can grow sunflowers by sowing seeds indoors into individual pots and transplanting the seedlings when they reach around 12 inches tall. 

Alternatively, plant sunflower seeds outdoors at least six inches apart - to thin to closer to 18 inches as they develop - into prepared soil and keep the seedlings protected from slugs as they start to appear. Discover the range of sunflower seeds available at Ferry-Morse

7. Zinnia

pink zinnias

(Image credit: Clare Gainey / Alamy Stock Photo)

There are so many options for zinnias to grow. Different colors, shapes, and sizes, are available to choose from and zinnias are a great cut flower as they are prolific plants that will keep producing as you cut. 

Either plant zinnia seeds indoors around 6 weeks before your last frost, or direct sow into the garden when the temperature increases in May. Zinnias want a warm spot, so pick the sunniest position in your backyard and sow seeds 5-8 inches apart into a small drill. Keep them moist and thin the seedlings as they emerge to give each plant 12 inches of space. Pinch the young plants when they are about 12 inches tall and you’ll be rewarded with longer stems and more flowers to cut. 

The 'California Giant Mix' of zinnia seeds, available at True Leaf Market, is a great choice for cutting thanks to its tall stems and spectacular 5-6" semi-double flowers in shades of rose, gold, red, pink, canary, coral, orange, and scarlet.

FAQs

Can I plant daisy seeds in May?

Leucanthemum, aka the Shasta daisy, can be sown in the fall or spring. The seeds can be sowed directly into the garden in May once the temperatures rise above 65°F and need to be kept well-watered to germinate. 

They want to be grown in a sunny position and not covered too much with soil as the seeds want sunlight to germinate. Once they bloom, deadhead shasta daisies to keep them blooming for longer and you can cut back shasta daisies each year in early summer by about a third to encourage a bushy growth habit and more flowers to develop.

Can wildflower seeds be planted in May? 

May is seen as a bit too late to plant wildflower seeds. The best time to sow if you want to create a wildflower garden or plant a wildflower meadow is in spring - when March or April is best - or alternatively in fall.


There are many more gorgeous flowers that you can plant in May on top of those outlined above. If you plan to sow seeds, or visit your local nursery or garden center to buy plants to add to your backyard ideas, May is a great month to get outside and be hands-on with the soil. 

Drew Swainston
Content Editor

Drew’s passion for gardening started with growing vegetables and salad in raised beds in a small urban terrace garden. He has gone on to work as a professional gardener in historic gardens across the UK and also specialise as a kitchen gardener growing vegetables, fruit, herbs, and cut flowers. That passion for growing extends to being an allotmenteer, garden blogger, and producing how-to gardening guides for websites. Drew was shortlisted in the New Talent of the Year award at the 2023 Garden Media Guild Awards.