Create an explosion of colour and scent in your garden this summer. From architectural alliums to dramatic dahlias and luscious lilies, find out which summer-flowering bulbs to plant and when to plant them to create a stunning summer garden.
While spring bulbs like daffodils and tulips hold a special place in my heart for providing the first pops of colour in the garden, summer-flowering bulbs offer the most dramatic blooms, with a dazzling array of shapes, sizes and colours to choose from. With just a handful of bulbs, you can fill your home with scented cut flowers and leave plenty in the garden for you to enjoy, along with the bees and butterflies.
You can plant summer bulbs as part of a mixed border, in their own bed or in containers. Summer bulbs are perennial, which means they'll give you luscious flowers year after year, making them an excellent low-cost investment for your garden.
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Bulbs for summer flowers
As a category, "summer bulbs" encompass a range of true bulbs, tubers, rhizomes and corms (if you're interested in the differences between them, read my guide to different types of bulbs). It's a broad group of plants, encompassing many popular varieties of cut flowers that bloom for different periods of the summer.
Early summer flowering bulbs:
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Alliums (May–June)
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Ranunculus (May–July)
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Dutch iris and bearded iris (May–June)
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Freesias (if grown indoors)
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Camassias (May–June)
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Peonies (May–June)
Mid-late summer flowering bulbs:
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Freesias (if planted outdoors)
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Zantedeschia, also known as the arum or calla lily (June–August)
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Begonia (June–October)
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Canna (July–October)
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Crocosmia (July–September)
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Dahlia (July–October)
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Gladioli (July–September if planted in succession)
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Asiatic and Turk's cap lilies (June–July)
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Oriental lilies (July–August)
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Agapanthus (July–September)
My top summer bulbs for scent are Oriental lilies and freesias, as well as the gentle scent of Paeonia 'Sarah Bernhardt'. Dahlias and begonias are the best choice for an extended blooming period, with both reliably flowering until the first frost. If you want flowers of a particular hue, you can filter our selection of summer-flowering bulbs by colour.
When to plant summer bulbs
You can plant hardy summer-flowering bulbs in the UK in early autumn. Hardy summer bulbs include alliums, lilies, irises, crocosmia, camassia and peonies. Aim to plant bulbs in September or early October.
Tender summer bulbs need to be planted in spring. If you're planting them directly outside, wait until April or May, when the soil has started to warm up. Alternatively, you can start dahlias and begonias indoors or under cover in March and plant them out once the risk of frost has passed. You may also be able to plant summer bulbs in pots in early spring as long as you can keep them in a frost-free greenhouse or conservatory.
If you have space, plant gladioli corms in batches a couple of weeks apart, so you can enjoy flowers over a longer period.
How to plant summer bulbs in the garden
Most summer-flowering bulbs grow and flower best in full sun. Begonias and Turk's cap lilies (Lilium martagon) are more adaptable and are good summer bulbs for shade, though avoid planting them in deep shade.
To prevent bulbs from rotting, make sure your soil is well-drained. If the ground is very compacted or tends to get waterlogged, plant your bulbs in pots or raised beds. You can also add a handful of grit to each planting hole to help with drainage.
If you have very acidic or alkaline soil, check your bulbs are compatible before planting. Most bulbs will tolerate neutral soils, but Oriental lilies prefer acidic soil and Asiatic lilies like alkaline conditions.Â
As a general guide, you plant most true bulbs at a depth equal to 2–3 times the height of the bulb. Rhizomes and tubers often need to be planted more shallowly, so check before digging! You can find detailed information on planting dahlias in our dahlia plant care guide.
Place bulbs in the planting holes with the nose (the pointed end) pointing up. When planting tubers, like dahlias, you want the eyes (where the shoots come from) to be upward. If you're struggling to identify which part of a bulb or corm the shoots will come from, plant them on their side. Replace the soil in the hole gently and water the bulbs.
Planting summer bulbs in pots
Most summer bulbs will grow well in pots; the exception being some of the larger dahlias and bearded irises. Lilies are often better grown in pots, especially if you don't have the correct soil conditions. Agapanthus are also a good choice for containers, as young plants thrive when their roots are restricted.
Large plants, such as dahlias, may need a pot to themselves, but for other flowers, like lilies and gladioli, you can plant multiple bulbs or corms in a large pot. You can also combine varieties of summer bulbs for a more varied display. This works particularly well when you mix tall, upright flowers, such as lilies, alliums or agapanthus, with filler plants like a cascading begonia or calla lily.
Choose a pot with drainage holes, and place some broken crocks or stones at the bottom so the holes don't become clogged. Mix plenty of sharp sand or grit in with your compost. For most bulbs, a multi-purpose compost will be fine, but if you're planting Oriental lilies, go for an ericaceous compost.
Plant your bulbs at the same depth you would in the ground, but closer together, to give a more concentrated display. Summer-flowering bulbs produce thirsty plants, so you'll need to water and feed them regularly during the growing season.
What to do with summer bulbs over winter
You can leave hardy summer bulbs in the ground year round. Tender plants, such as dahlias, begonias and gladioli, may not survive outside, and it's safer to lift and store the bulbs over winter. Make sure the bulbs are completely dry before storing and check them regularly for rot. If you have plants in containers, move these to a frost-free location for the winter months.
Related pages
Get more detailed information on planting different types of flower bulbs on our plant care pages:
FAQ
When do you plant summer bulbs?
Hardy summer-flowering bulbs, such as alliums, crocosmia, irises and lilies, can be planted in September or October and left in the ground over winter. Tender bulbs, like dahlias, begonias, freesias and gladioli, should be planted in spring once the ground has warmed up. For earlier flowering, you can start tender bulbs in pots in March and keep them indoors or in a frost-free greenhouse until nighttime temperatures are above 10°C.
Are summer bulbs perennial?
Most summer bulbs are perennial. Although the flowers and foliage die back in autumn, they will return the following year, as long as you look after the bulbs. Tender bulbs can rot during wet UK winters, so the best way to ensure they flower again the following year is to lift and store them over winter.
Can I plant spring and summer bulbs together?
You can plant spring and summer bulbs together, especially hardy summer bulbs that you plant in early autumn. Alliums, for example, look fantastic combined with daffodils and tulips in a pot or border. Combining tender bulbs and spring bulbs in a pot is more difficult, as you can't plant them at the same time, but with a bit of planning, you can combine these flowers in a bed or border.
