May Flowers: Transform Your Garden with These Late-Spring Blooms

Late spring brings a burst of colour to the garden, with early-flowering perennials, shrubs and spring bulbs putting on a show. Plant a lilac or ceanothus to attract masses of bees and butterflies to your garden, or perk up a patio garden with vibrant azaleas, wallflowers and geums.

May is a wonderful month in the garden. The colder days are behind us, and new flowers are popping up everywhere. If you're lucky enough to have a wisteria in your garden, it will steal the show this month, but the flowering shrubs I've selected below offer an equally stunning display for smaller gardens.

While most perennials don't really get going until next month, geums and Erysimum are in their element and, along with tulips and euphorbia, give you plenty of options for a vase or bouquet of spring flowers. 

May is the perfect time to sow flower seeds outside. Find out what to plant now in my checklist of gardening jobs for May.

Syringa 'Miss Kim'

May is the most wonderful month for lilacs, which are grown primarily for their scented flowers, which are highly attractive to pollinators. The common lilac, Syringa vulgaris, can grow to quite a height, but Syringa pubescens subsp. patula 'Miss Kim' is a slow-growing, compact variety that's ideal for small gardens. You can also grow it in a large pot, as long as you water it regularly. Lilacs prefer neutral or alkaline soil.

Syringa 'Miss Kim' has an RHS Award of Garden Merit for its reliability in UK gardens. In spring, purple buds bloom into fragrant light-purple flowers that fade to near-white as they age. This lilac has a second season of interest in autumn, when the green leaves turn scarlet before they fall. Lilacs need to be planted in full sun to flower well.

Plant it with…

Nepeta 'Cat's Pajamas': This hardy, long-flowering perennial is brilliant for the front of a border. Its early flowers complement those of Syringa 'Miss Kim', and it will continue to bloom through to early autumn, when the lilac is ready to take centre stage again.

Buddleia 'Buzz Lavender': Buddleias and lilacs have similar blooms, but they flower at different times of the year. Plant both together to get a continuous display of flowers that will attract all the bees to your yard.

Erysimum 'Bowles's Mauve': Wallflowers really earn their place in the garden with a super long flowering season. This RHS-recommended variety flowers from later winter and can often keep going through to autumn.

Geum 'Totally Tangerine'

Geums bloom earlier than most perennials and are a must-have for May flowers. Geum 'Totally Tangerine' has been bred to flower for a long period, from late spring through to September. It produces lovely soft apricot orange flowers with papery petals on long, fine stems. A lovely flower to display in a vase or simply enjoy in your garden.

Geum 'Totally Tangerine' gives the best display of flowers when planted in full sun, though it will also do well in partial shade. Keep deadheading the flowers to get new blooms all through the summer months.

Plant it with…

Allium 'Purple Sensation': Purple alliums look stunning when dotted amongst the pale orange flowers of Geum 'Totally Tangerine'. A classic border combination for late spring and early summer.

Geranium 'Azure Rush': Pair Geum 'Totally Tangerine' with this lavender-blue hardy geranium for flowers throughout the summer months – perfect for an easy cottage garden border.

Lupin 'Beefeater': The striking spikes of brilliant red flowers are a stunning contrast to the airy stems and light flowers of Geum 'Totally Tangerine'. Another classic cottage garden pairing for a sunny bed.

Ceanothus 'Victoria'

Ceanothus are brilliant low-maintenance shrubs which cope exceptionally well with the trending pattern of wet winters and dry summers that we're experiencing in the UK. Once established, they're drought tolerant and require little pruning or maintenance. As a reward for your lack of effort, you'll get a wonderful display of true blue flowers in spring or autumn.

Ceanothus 'Victoria' is an evergreen, spring-flowering ceanothus. It's a bushy, fast-growing shrub, which you can grow at the back of a border or train up a sunny wall. I have this variety in my sunny back garden, and it's a bee magnet at this time of year. Ceanothus 'Victoria' is one of the hardiest cultivars, but it does need a sunny, sheltered spot with well-drained soil.

Plant it with…

Stipa 'Pony Tails': The feathery texture of this ornamental grass is a lovely light contrast to the dark green leaves and structured form of Ceanothus 'Victoria', and it will thrive in similar sunny, dry conditions.

Lavender stoechas: French lavender flowers early, from May onwards, and will keep flowering throughout the summer. The dark purple, lilac-tipped flowerheads and gentle aroma make it a perfect companion to ceanothus.

Achillea 'New Vintage Rose': This pretty pink yarrow is drought tolerant and its bright jewel-link flowers will shine against the dark evergreen backdrop of Ceanothus 'Victoria' in summer and early autumn.

Azalea 'Orange Beauty'

Azaleas are at their peak in May, and Azalea 'Orange Beauty' is one of the best, with a profusion of orange and salmon flowers that will add a striking pop of colour to any garden. It is a compact, evergreen shrub that will add year-round structure to beds in a variety of gardens. Plant it in front of larger rhododendrons in a large border or woodland garden, or cluster with other dwarf azaleas in smaller gardens for a dramatic burst of spring colour. 

Azaleas pair well with other acid-loving plants like rhododendrons, pieris, hostas and acers. If you don't have suitable soil, grow it in a large container with ericaceous compost. It's a lovely shrub to add structure to a patio garden.

Plant it with…

Pieris 'Sarabande': This evergreen shrub flowers early in spring, providing interest in the months before the azalea blooms. It's happy grown in pots or in a partially shaded border.

Acer 'Garnet': The deeply dissected, feathery purple leaves of this acer offer a lovely textural contrast to the azalea's leathery green leaves. In spring, Acer 'Garnet' lets Azalea 'Orange Beauty' shine, but in autumn, it takes centre stage as its leaves turn vibrant scarlet. 

Blechnum spicant: This evergreen fern thrives in hummus-rich, acidic soil and woodland settings. An excellent groundcover option to grow with azaleas.

Euphorbia amygdaloides var. robbiae

A star of RHS Chelsea Flower Show gardens and lauded by the RHS, this euphorbia will grow pretty much anywhere, but it's particularly good for areas of dry shade. In spring, Euphorbia 'Robbiae' produces tall spikes of lime-coloured bracts; these modified leaves curl around the true flowers, which are inconspicuous. The zingy flower spikes light up shaded parts of the garden and make an excellent cut flower – I've had them in a vase for up to two weeks. Be sure to wear gloves when cutting stems, as the sap is an irritant.

Euphorbia amygdaloides var. robbiae prefers partial or full shade, but it will grow in full sun. It spreads via underground rhizomes, which makes it an excellent groundcover plant, but I can personally attest to the fact that when left unchecked, it can take over your garden. While I have been known to curse it for being an unwelcome visitor to parts of my garden, at this time of year, it's so pretty that I can't help leaving it to shine.

Plant it with…

Hydrangea 'Annabelle': Plant this popular hydrangea behind Euphorbia 'Robbiae' in a partially shaded border to enjoy snowball-like flowers in summer and autumn. Hydrangea 'Annabelle' is our May flower of the month – get 25% off when you buy it this month.

Polystichum neolobatum (Asian Saber Fern): This lush green fern loves a shady spot, and once established, it will cope well with dry shade conditions. It offers a wonderful textural contrast to Euphorbia 'Robbiae' and the two make a great combination for planting under medium and large trees.

Liriope 'Moneymaker': This autumn-flowering perennial lies low during spring, but in late summer, it's a star of shady borders, with stalks of lavender-coloured buds and flowers.

FAQ

What is May's birth flower?

Lily of the valley and hawthorn are the birth flowers for the month of May. Hawthorns are native British trees that are a brilliant addition to hedges and gardens, providing spring flowers and autumn berries. Lily of the valley (Convallaria majalis) is a shade-loving plant that produces delicate, white bell-shaped flowers in spring, which are popular for posies and bouquets.

What flowers are in season in May?

The garden is full of colour in May with tulips, alliums, peonies and early-flowering geraniums. Lilacs are in full bloom, along with weigelas and ceanothus, and if you have acid soil, rhododendrons and azaleas provide a dramatic burst of colour. Plant wallflowers (Erysimum), senetti and sweet alyssum in pots and containers to brighten up your patio.