Horticulture Magazine

These 15 Shrubs That Flower In Summer Are Colin Skelly’s Top Picks

a monarch butterfly sat on a buddleja plant
By ED BOWRING
Ed Bowring, BSc, DipSTH, Horticultural Therapist & Gardener

Ed is a horticultural therapist, professional gardener and writer. Ed has a BSc in Occupational Therapy from Coventry University and a Diploma in Social and Therapeutic Horticulture (DipSTH) via Thive, the RHS and Pershore College. Ed runs a community kitchen garden in West Sussex, where he leads horticultural therapy sessions.

/ Updated September 19th, 2024
Reviewed By COLIN SKELLY

Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.

/ Meets Our Editorial Guidelines

With some careful planning, shrubs can inject a dazzling display of colour, not only throughout the summer, but during the rest of the year as well!

With the bonus of being relatively low maintenance, shrubs can provide vibrant hues or calming pastel shades to adorn your garden, along with providing important height and structure.

Whether for a contemporary design or a cottage garden there are shrubs to suit.

Shrubs come in a plethora of choices, evergreen or deciduous, for ornamental or screening purposes and even scented.

The choice is endless, but here are some of the best to inspire you on how to provide stunning colour during the summer months here in the United Kingdom.

1) Hydrangea

white flowering Annabelle hydrangea
  • HARDINESS: H5
  • PREFERRED ASPECT: PART SHADE; SHELTERED
  • TYPICAL FLOWERING MONTHS: JULY – SEPTEMBER
  • RECOMMENDED VARIETIES: ‘Early Blue’, ‘Vanilla Fraise’, ‘Annabelle’

Hydrangeas, originally from Asia and the Americas, are one of the best all-round shrubs and are widely available in vibrant pinks, cool blues and elegant whites.

They grow well in full sun or part shade and need to be kept moist and in a sheltered spot.

Hydrangea macrophylla, with classic mophead flowers, are available in pink and blue and will flower from June through to August.

Amazingly the colour of their flowers is soil dependent, with acidic soil producing lilac flowers and alkaline soil pink blooms.

H. macrophylla ‘Early Blue’ grows to H1.5m x W1.5m and is a wonderful variety showcasing large pale blue flowers that darken as the summer goes on.

H. paniculata are a great variety producing pyramid-shaped flowers.

Hydrangea paniculata ‘Vanilla Fraise’ in bloom
H. paniculata ‘Vanilla Fraise’

H. paniculata ‘Vanilla Fraise’ must be a favourite though with its creamy white flowers, which as the summer drifts on, turn a wonderful pink.

Definitely one for the back of the border as it can reach H2.5m x W1.5m over time.

For a classic white nothing compares with H. arborescens ‘Annabelle’. A potentially large shrub, H2.5 x W2.5m, it can be kept compact through regular pruning.

Large white balls of flowers, so big that the stems may need staking, usually appear in July and last for months. A stunning shrub and true favourite.

Don’t let hydrangeas dry out though as they are often one of the first to wilt, especially if kept in a pot.

“Hydrangeas are hugely popular garden shrubs, and rightly so,” says Master Horticulturist Colin Skelly.

“For the price of an annual prune, they will provide blooms from mid to late summer and look good as they fade into autumn.

“Keep well mulched to optimise soil moisture. My favourite is H. arborescens and its cultivars, but all of the species are the parents of many worthy garden cultivars.”

2) Lavender

lavender bushes
  • HARDINESS: H5
  • PREFERRED ASPECT: FULL SUN; SHELTERED
  • TYPICAL FLOWERING MONTHS: JUNE – JULY
  • RECOMMENDED VARIETIES: ‘Hidcote’, ‘Munstead’

For a south-facing border or sunny terrace, lavender is a great choice.

From the Mediterranean, lavender plants love the sun and heat and are equally at home in a border or a pot.

French and Spanish varieties tend to be slightly taller, but are less hardy than the English varieties, needing protection during the cooler months.

For this reason, we’d go for an English lavender of which there are many.

Lavandula angustifolia or English Lavender will bloom from July to September and attract all manner of pollinators to the garden.

purple flowering Lavender 'Hidcote'
Lavender ‘Hidcote’

The classic ‘Hidcote’ (H.5m x W1m) and ‘Munstead’ (H.5m x W1m) varieties both produce wonderfully scented purple flower spikes for weeks on end.

Both compact and easily available, ‘Hidcote’ produces a smaller and deeper purple flower compared to the larger & paler ‘Munstead’ flower.

Lavender requires free draining soil to thrive and will sulk if left in wet heavy soil over winter.

Planting out in spring and adding horticultural grit to the soil mix will give them the best start. 

3) Buddleja

peacock butterfly feeding on  Buddleja davidii
  • HARDINESS: H6
  • PREFERRED ASPECT: FULL SUN OR PART SHADE; EXPOSED OR SHELTERED
  • TYPICAL FLOWERING MONTHS: JULY – OCTOBER
  • RECOMMENDED VARIETIES: ‘Santana’, ‘Buzz Blue’, ‘Black Knight’

Buddlejas (buddleias) are more commonly known as the butterfly bush due to their insane capability of attracting butterflies.

With purple, pink, blue and white conical flowers buddlejas deserve a place in every garden.

With careful deadheading they can bloom throughout summer and even though they thrive in almost every spot, they prefer a sunny and dry position.

B. davidii ‘Santana’ produces vibrant red-purple panicles up to 50cm long.

It can reach H4m x W4m if left to its own devices, but a spring prune will keep it more compact if desired.

Buddleja davidii 'Black Knight'
B. davidii ‘Black Knight’

Buddleia ‘Buzz’ have been bred to stay small and are perfect for a small border or patio pot growing to H1m x W1m.

‘Jazz Blue’ shows off stunning blue flowers all summer long, attracting bees and butterflies to your garden.

For a real show stopper, nothing beats B. davidii ‘Black Knight’.

A large shrub growing up to H3m x W3m, it is covered with intense deep purple flowers through the summer months.

4) Rose

pink rose shrubs
  • HARDINESS: H6
  • PREFERRED ASPECT: FULL SUN; SHELTERED
  • TYPICAL FLOWERING MONTHS: JUNE – JULY
  • RECOMMENDED VARIETIES: ‘Gloire du Midi’, ‘Freedom’, ‘Gloire de Guilan’

With roses being one of the broadest groups of plants there’s a rose for every situation.

From small varieties such as polyantha and patio to the larger hybrid tea and damask, the choice is endless.

Roses thrive in full sun, although some are suited to shade and must be kept well-watered and fed.

‘Gloire du Midi’ is perfect for a patio pot growing only to H.5m x W.5m.

Preferring full sun, it produces masses of slightly scented scarlet red flowers for months on end, as it is a repeat flowerer.

Red Gloire du Midi Roses on thorny stems
‘Gloire du Midi’ Rose

Rosa ‘Freedom’, a hybrid tea, displays glorious deep yellow blooms throughout the summer.

A vigorous bush type habit, yet only growing to H.8m x W.6m. it will bring life to any border.

For an old damask variety, nothing beats ‘Gloire de Guilan’.

A large shrub growing to H1.5 x W1m it produces a one-off abundance of double pale pink flowers with good scent.

With good disease resistance it is perfect for a sunny or part shaded border.

5) Ceanothus

blue flowers of ceanothus
  • HARDINESS: H4
  • PREFERRED ASPECT: FULL SUN; SHELTERED
  • TYPICAL FLOWERING MONTHS: VARIES
  • RECOMMENDED VARIETIES: ‘Concha’, ‘Trewithen Blue’, ‘Blue Cushion’

The sun loving Californian lilac or ceanothus can be evergreen or deciduous and their flowers provide a burst of blue in early summer.

They require moist, but well-drained soil and will thrive in a sheltered and sunny spot.

Ceanothus ‘Concha’ AGM is an evergreen eventually growing to H3m x W3m.

With indigo blue flowers it injects some wonderful early summer colour into any garden.

Having received the Royal Horticultural Society AGM award, it is proven to perform reliably well in the garden.

a honeybee harvesting pollen from blue Ceanothus 'Concha' flowers
C. ‘Concha’

If you have the space then C. arboreus ‘Trewithen Blue’ must truly be considered.

A vast shrub or small tree, it can grow over time to a gigantic H6m x W8m and is hardy down to -10C.

C. ‘Blue Cushion’ is better suited for a smaller position reaching H1m x W2m.

Bearing bright blue fluffy flowers in early summer, it is loved by pollinators.

6) Cistus

pink Cistus purpureus flowers
  • HARDINESS: H4
  • PREFERRED ASPECT: FULL SUN; SHELTERED
  • TYPICAL FLOWERING MONTHS: JUNE – JULY
  • RECOMMENDED VARIETIES: ‘Gold Prize’

Another sun-loving shrub worthy of including is the cistus or rock rose.

Again, from the Mediterranean, it is happiest in a hot dry border and will add lots of colour during the summer months.

Available with pink, white or red flowers they are fairly hardy, but may need protection during the coldest weather.

Cistus creticus grows to a manageable H1m x W1m and produces vibrant pinky-purple flowers with a yellow centre.

pink Cretan Rose shrub in a garden
Cistus creticus

For a larger shrub, C. ladanifer or the gum cistus can reach H2m x W1.5m and displays cool white flowers with a dark red basal stain from June to August.

It is hardy down to -10C so should fair well here in the UK except in the harshest of winters.

For a variegated option, you could try C. × hybridus ‘Gold Prize’ with its green and gold leaves.

Reaching H1.5m x W1.5m it will brighten up a sunny spot with its white flowers with yellow centres.

7) Deutzia

pink Deutzia
  • HARDINESS: H5
  • PREFERRED ASPECT: FULL SUN OR PART SHADE; SHELTERED
  • TYPICAL FLOWERING MONTHS: APRIL – JULY
  • RECOMMENDED VARIETIES: ‘Raspberry Sundae’, ‘Nikko’, ‘Strawberry Fields’

Deutzias mainly originated from Asia and are relatively uncommon here in the UK, but are definitely worth considering.

They are deciduous shrubs that will adorn your garden with beautiful white or pink star-shaped flowers, which are sometimes scented.

Preferring a south or west-facing aspect they require full sun or part shade and shelter away from winds.

Deutzia ‘Raspberry Sundae’ is a small compact variety that will grow to only H1m x W1m.

white flowering Deutzia Gracilis 'Nikko'
D gracilis ‘Nikko’

In early summer stunning pink and white scented flowers appear that can last for weeks.

Being deciduous it loses its leaves in winter, but only after turning a lovely auburn colour.

D. gracilis ‘Nikko’ is another smaller variety reaching H1m x W1m and produces the most stunning white flowers.

Being relatively hardy this variety will withstand temperatures of down to -15C.

For a stunning new variety, it is worth considering D. x hybrida ‘Strawberry Fields’.

It is one for a larger spot reaching H2m x W2m over time and will dazzle with its pink flowers during June and July.

8) Daphne

Daphnex Burkwoodii 'Carol Mackie'
  • HARDINESS: H5
  • PREFERRED ASPECT: FULL SUN OR PART SHADE; SHELTERED
  • TYPICAL FLOWERING MONTHS: VARIES
  • RECOMMENDED VARIETIES: ‘ETERNAL FRAGRANCE’, ‘CAROL MACKIE’

The shrubs mentioned above flower during the summer months, but if you are after a shrub that will flower on and on from spring through to autumn then Daphne × transatlantica ‘Eternal Fragrance’ is hard to beat.

Suitable for large pots or containers, ‘Eternal Fragrance’ will live up to its name and produce deliciously scented small white flowers.

The scent is so good it would be a shame not to put it somewhere you’ll walk past often so you can enjoy it.

Daphne 'Eternal Fragrance'
D. ‘Eternal Fragrance’

This daphne is rather compact and slow-growing reaching H1m x W1m over time.

Ideally suited to full sun, it can cope with part shade, but needs to be in a sheltered spot.

A word of warning though, daphnes don’t take well to being transplanted, so it’s worth trying to put it in its final position first time round.

9) Olearia

white and yellow flowers of New Zealand Holly under sunlight
  • HARDINESS: H4
  • PREFERRED ASPECT: FULL SUN; EXPOSED OR SHELTERED
  • TYPICAL FLOWERING MONTHS: JULY – AUGUST
  • RECOMMENDED VARIETIES: ‘Macrodonta’

10) Fuchsia

pink drooping flowers of Fuchsia 'Whiteknights Pearl'
  • HARDINESS: H4
  • PREFERRED ASPECT: FULL SUN OR PART SHADE; SHELTERED
  • TYPICAL FLOWERING MONTHS: JUNE – SEPTEMBER
  • RECOMMENDED VARIETIES: ‘Whiteknights Pearl’

11) Hibiscus

three large flowers of hibiscus blue bird
  • HARDINESS: H5
  • PREFERRED ASPECT: FULL SUN; SHELTERED
  • TYPICAL FLOWERING MONTHS: JULY – SEPTEMBER
  • RECOMMENDED VARIETIES: ‘BLUE BIRD’

12) Salvia

red and white salvia hot lips
  • HARDINESS: H5
  • PREFERRED ASPECT: FULL SUN; SHELTERED
  • TYPICAL FLOWERING MONTHS: JULY – AUGUST
  • RECOMMENDED VARIETIES: ‘Hot Lips’

13) Spirea

butterfly sat on pink spirea flowers
  • HARDINESS: H6
  • PREFERRED ASPECT: FULL SUN OR PART SHADE; EXPOSED OR SHELTERED
  • TYPICAL FLOWERING MONTHS: JUNE – AUGUST
  • RECOMMENDED VARIETIES: ‘NANA’

14) Escallonia

flowering escallonia on blue sky background
  • HARDINESS: H4
  • PREFERRED ASPECT: FULL SUN; EXPOSED OR SHELTERED
  • TYPICAL FLOWERING MONTHS: JUNE – OCTOBER
  • RECOMMENDED VARIETIES: ‘LANGLEYENSIS’

15) Potentilla

King Cup Potentilla
  • HARDINESS: H7
  • PREFERRED ASPECT: FULL SUN OR PART SHADE; EXPOSED OR SHELTERED
  • TYPICAL FLOWERING MONTHS: JUNE – SEPTEMBER
  • RECOMMENDED VARIETIES: ‘Medicine Wheel Mountain’, ‘King Cup’

Shrubs can sometimes be thought of as rather municipal or boring, but this doesn’t have to be the case as there are some truly beautiful shrubs that will brighten up any garden over the summer months.

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