Horticulture Magazine

15 Summer-Flowering Bulbs For Later Blooms

white agapanthus flowers

Summer flowering bulbs make excellent border and container blooms, while they also look magnificent as cut flowers in an indoor vase, too.

Although spring is the season most commonly associated with floral blooms, there are many varieties of plants that bloom later in the year as well.

Summer flowering bulbs are an excellent means of bridging the gap between spring and autumn with a burst of bright colour, with many species offering truly breath-taking displays that’ll add zing and zest to your garden.

As well as being high impact, summer flowering bulbs are also among the easiest to maintain.

The relatively small dimensions of many varieties means that they don’t demand much in the way of space, allowing you to squeeze them into a border or place them in a pot and allow them to do their thing.

Other than digging up the bulbs of less hardy varieties in winter to spare them from the ravages of Jack Frost, they require little in the way of upkeep, too.

While summer flowering plants are most readily available in fully grown formats in gardening centres around the country, purchasing them after they’re grown is expensive and unsustainable.

Instead, procure the bulbs in early spring and plant them as soon as the first frost has passed to give them the best chance of taking root.

Generally speaking, they should be planted at three times their depth and spaced at three times their width, though it’s always a good idea to check the packet or label for any specific instructions.

So if you’re looking for some summery additions to spruce up your garden during the warmer months, we’ve put together a list of summer flowering bulbs for your reading pleasure below.

Exact flowering times may vary, but all will come into their own during June, July or August – so pick your favourites and begin planning next year’s display today.

1. Agapanthus

blue agapanthus flowers in terracotta pots
Striking blooms become architecturally intriguing seed heads in autumn.

Hailing from South Africa, agapanthus is one of the most visually impressive summer blooms you’ll encounter.

Their slender stems support bobbing clusters of trumpet-like flowers in the most vivid tones of purple, blue and white, standing proud and handsome above your borders from mid to late summer.

They lend themselves well to container planting, meaning you can arrange and rearrange them in the garden with the minimum of fuss, or simply place them on your balcony or terrace if space is at a premium.

Bees love them too, so they’ll bring a buzzing atmosphere (sorry) and plenty of biodiversities into your home.

2. Allium

rows of purple and white allium flowers
High and handsome.

Allium is another species of summer flowering bulb which towers over its counterparts. Like agapanthus, the blossoms are made of rounded clusters of flowers that look enchanting in bloom and ethereal after the season has come to a close.

Their stature is great for adding height and intrigue to a sunny border, while it’s a good idea to obscure the lower, less interesting reaches of their foliage with smaller plants – especially after they have died back in winter.

They do look spectacular nestled in behind others, but just make sure they have enough exposure to sun and air to reach their full potential.

Alternatively, if you really want to make a splash, you can follow the planting suggestion pictured above and create alternating rows of colourful allium blooms.

3. Begonia

orange reiger begonias
As unfussy about their surroundings as they are easy on the eye.

Given that begonia plants will thrive in both sun and shade, they’re the ideal option for injecting some oomph into a darker corner of the garden.

Indeed, they’re among the lowest maintenance summer flowering bulbs you can hope to find, but that doesn’t mean they won’t turn heads aplenty.

Equally at home in borders, pots and hanging baskets, begonias are available in a broad range of tones, from delicate pastels to punchy popping sprays.

Just be mindful that begonias are toxic to pets, so make sure your furry friends don’t get over-familiar with your display and you’ll be fine.

4. Bearded iris

a bed of bearded iris flowers
Fragrant and fetching.

As the name suggests, bearded irises are immediately recognisable by the draping petals which form part of their delicate blooms.

In contrast to the almost papery texture of their flowerheads, bearded irises also sport sturdy, strap-like foliage, forming a pleasing juxtaposition that is guaranteed to liven up your garden’s appearance.

These flowers are extremely fond of the sun, so make sure they aren’t surrounded by other plants which will crowd out their exposure, while the intoxicating aroma which accompanies some varieties makes them an olfactory delight as well as a visual one.

5. Canna

close up of red and yellow canna lily
Fiery flowers.

Cannas are renowned for the vibrancy of their palette and the dramatic nature of the patterns – but it’s not just the flowers that will make your canna plant stand out from the crowd.

They’re also famous for their unusual and irresistible foliage, which comes in forms large and leathery enough to recall a tropical jungle.

If you fancy replicating some of that exotic appeal in your own backyard, simply plant the bulbs before the end of April and take care to leave any new shoots exposed above the surface of the soil.

Follow that formula and you’ll be rewarded with jaw-dropping displays right throughout summer.

6. Crocosmia

a butterfly sat on crocosmia flowers
Hellish by name but divine by nature.

There are a wide variety of different crocosmias to choose from, but the defining characteristic shared by almost all of them is the blistering red hue of their floral offerings.

The ‘Lucifer’ plant pictured above is a tall specimen that’s perfect for adding a fiery flourish to your display at height, while smaller alternatives like ‘Mistral’ can make use of confined spaces, crowded borders or gravel gardens.

Bees and butterflies are absolute suckers for them, so if you’re really lucky, you might even spot one of the incredible species in the image!

Unlike many of the other options on this list, crocosmia are fully hardy too, so there’s no need to dig them up and take them indoors during winter.

7. Dahlia

orange dahlia in the garden
Bright, bold and utterly beautiful.

With their spherical shape, dahlias are among the most architecturally pleasing of all summer flowering bulbs.

They sit proudly atop their stems like a monarch surveying their kingdom and should be treated as such – so be sure to plant them in full or partial sun to maximise their appeal.

The wide range of varieties available means you can tailor them to your existing colour scheme, and despite their Mexican origins, they’re fully at home in even the most quintessential of British gardens.

They don’t mind getting thirsty, either, meaning they’ll continue to bloom right throughout summer and deep into autumn if given the appropriate deadheading attention.

Learn how to overwinter them in this guide.

8. Daylily

Hemerocallis "Wild Horses" blooming in a garden border
Hardy in temperament but soft on the eye.

Also known by their botanical name Hemerocallis, daylilies are an absolute dream for a hands-off horticulturist.

That’s because they’re hardy enough to go straight into the ground in spring and stay there right throughout the winter – frosts won’t kill them off and they’ll come back even stronger the following year.

Best of all, however, is their stunning appearance. With delicately variegated petals serving as a backdrop to tendril-like stamens, they’re a sight for sore eyes in any border or container.

They can withstand long periods without water, but they do insist on getting their daily quota of Vitamin D – so be sure to plant them in full sun.

9. Freesia

close up of a freesia bouquet
African aesthetics.

Another beautiful summer bloomer hailing from South Africa, freesias have become one of the UK’s favourite bulbs to enjoy throughout the warmer months of the year.

They love full sun and may struggle in particularly cold parts of the UK, where they’ll certainly appreciate the extra insulation offered by a greenhouse or conservatory, but they can do well outdoors, too.

They’re space-efficient and can be grown in clumps, while their strong fragrance and stunning appearance makes them an excellent choice for a cut flower to take indoors, too.

10. Gladiolus

gladiolus flowers
You’ll be glad you went with gladioli.

Instantly recognisable from their spires of funnel-shaped flowers draped decadently from a spiky stem, gladioli are one of the most popular choices for a summer bloomer right throughout Britain.

Indeed, they almost became a victim of their own success in recent years, with their ubiquity leading some to claim they are old-fashioned and off-trend.

However, exciting new varieties and hybrids have brought them back in vogue. They come in all different colours and styles to suit any aesthetic, while they’re a must-have ingredient for any cut-flower display worth its stripes.

11. Oriental lily

oriental lily in the garden
The attraction of the Orient.

Defined by their showy flowerheads and invigorating aromas, oriental lilies are the star of any show they feature in.

They’re available in all different shapes and sizes, from diminutive ground-dwellers that are perfect for providing coverage to tall upright specimens that add flamboyance and finesse at levels.

Due to their Eastern origins, however, they might find the British climate a little tricky to cope with, so it’s a good idea to plant them indoors and transplant them outside once they have begun to bloom – then dig them up and wrap them in cotton wool before the first frost sets in.

12. Peony

pink peonies
Oversized flowerheads are a boon and a bane.

The large blossoms of peonies are what make them a star attraction in your garden – but the sheer weight of the flowerheads can also serve as a drawback, causing the plant to collapse on itself.

Sidestep that particular issue by staking out a small support system (made from bamboo canes and twine, for example) over them when planting.

The stems can grow through the supports and the foliage will obscure them, but the flowerheads won’t become overburdened under the weight of their own gorgeousness.

Their subtle fragrance and striking appearance make them a superb cut flower, too.

13. Polianthes

White Polianthes tuberosa in focus
As pungent as potpourri on a stem.

Polianthes is another genus of striking summer flowering bulbs which hail from Mexico – and those Latin roots mean it won’t fare well in temperatures below 15°C at the outset.

That’s why it’s advisable to grow your bulbs in a greenhouse or indoors until they’re big enough to fend for themselves, then transplant them into your desired location outside.

They are, however, hardy enough to survive until the next season once they reach maturity, so there’s no need to remove them indoors.

Though they might take a little more elbow grease to cultivate than some alternatives, their breath-taking waxy blooms and strong scent make them a favourite throughout the UK.

14. Sparaxis

Double California Sparaxis Flowers in orange and white
This harlequin will certainly add interest to your display.

Sometimes known as harlequin flowers, sparaxis are available in a variety of different colours and hues – though they’re invariably recognisable by the kaleidoscopic centre of their star-shaped blooms.

The tricolour aspect of their appearance is what draws the eye, with a yellow-and-black heart encircled by vibrant magentas, lilacs, burnt oranges and many more, depending on the specific type you opt for.

Topping sword-like foliage, their blooms will begin to unfurl in midsummer until the beginning of autumn, providing plentiful panache for your border or container.

15. Watsonia

salmon pink watsonia during summer
Tantalisingly tropical.

Named after the 18th-century botanist and apothecary Sir William Watson, watsonias originated in South Africa but were brought over to the UK over 200 years ago and have become firm favourites ever since.

Alternatively known as bugle lilies, their trumpet-like blossoms normally come in peach or orange hues, bringing a calming pastel aesthetic to your garden.

Bees, birds and butterflies will love them as well, meaning you can enhance the biodiversity in your garden with their inclusion.

Ideal for accentuating a tropical theme, watsonias are as lovely to the nostrils as they are to the eyes.

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