What flower seeds to sow in May – Inspiration & Growing guide

what to sow in May 1024x858 - What flower seeds to sow in May - Inspiration & Growing guide

It’s May time already, and temperatures are starting to rise! After some frequent rain spells your garden is starting to come to life. It’s also the perfect time to start sowing some beautiful and practical plant varieties which will provide food and colours to your garden for the coming months.

Want to jazz up your garden and add some interesting variety this year? Let’s look at some great May sowing ideas, seeds you can plant right now to get your garden ready for the months ahead.


geranium 1024x683 - What flower seeds to sow in May - Inspiration & Growing guide
The hardy geraniums are undoubtedly one of the most popular groups of garden plants. They are beautiful, reliable and endlessly various. Today’s stunning hybrids are the modern flag bearers of a genus with a long history in our gardens.

One of the longest bloomers in the garden, hardy geranium bears flowers for months at a time. It produces jewel-tone, saucer-shaped flowers and mounds of handsome, lobed foliage. It needs full sun, but otherwise, it is a tough and reliable plant, thriving in a wide assortment of soils.


Fill pots or cells of trays with a good soil. Sow the seeds 2.5cm (1in) apart, on the surface of the compost and cover lightly. Keep soil slightly moist but not wet. Perennial geraniums often germinate over several months, usually between 30 to 90 days at temperatures around 5 to 10°C (41 to 50°F). Seed trays should not be discarded prematurely. Constant moisture must be maintained. Do not leave in direct sunlight.

Swiss chard

swiss chard shuttersk 1024x683 - What flower seeds to sow in May - Inspiration & Growing guide

Tangy, colourful leaves and stems are an excellent cooked vegetable and a tremendous source of vitamins.

Swiss Chard is a very versatile, close relative of garden beets. It is easy to grow and will provide fresh greens all season from one sowing. Chard can be used at baby-leaf or full-size stage and is also popular in mixed ornamental containers. Bright lights variety has green or bronze leaves with stems of gold, pink, orange, purple, red, and white with bright and pastel variations.


Sprouts in 7-14 days. Sow seeds 1cm (½”) deep, spaced 10-30cm (4-12″) apart in rows 45cm (18″) apart. Ideal pH: 6.0-6.5. Swiss chard prefers loose, deep, and fertile soil rich in organic matter.

Morning Glory

morning glory 1024x683 - What flower seeds to sow in May - Inspiration & Growing guide

Morning glory flowers open with the morning sun and close when it sets. Though each flower only lasts for one day, their abundance and beauty have made them a garden favourite for centuries. Large, brilliant fiery-red flowers. 13ft (4m). A splendid climber for covering trellis-work, chain-link fences and such with a dense screen of foliage, and with a profusion of gorgeous, trumpet-shaped flowers 5ins and more in diameter.


For faster germination, nick the seed coat with a sharp knife or soak the seed in warm water overnight. Plant the nicked seeds 1/4″ deep and keep the soil evenly moist but not soggy until germination, which should take place in 7-10 days with adequate warmth.

Do you want to take your garden to the next level?

Planning a garden all year round and sourcing seeds from all over the world is hard work, especially if you want to keep your garden interesting year after year.

That’s why we created Gardeners Box, each month receive the hand-curated seeds we recommend sowing right now to brighten your garden, along with detailed instructions, and plant markers all starting from just £9.99. Click here to find out more.

Whats in Box Small Square border - What flower seeds to sow in May - Inspiration & Growing guide