Beautiful blooming bulbs are not just for spring. Summer flowering bulbs make a fabulously colourful display, and the time to plant them is now. Grow summer bulbs to brighten your borders and containers, or grow for your own cut flower displays.
Dormant bulbs and roots are widely available in garden centres, either loose or pre-packed, or to buy online. They offer great value and even tender ones can be kept from year to year, with a bit of winter care.
Here’s our top choice of summer bulbs to grow:
Gladioli
Gladioli are favourites for flamboyant frilly blooms in many vivid colours. They are great for border displays and make excellent cut flowers. Less common – and more subtle – is Gladiolius murieliae (formerly Acideranthera), which has elegant white, purple-centred, fragrant blooms. The bulbs are small but it’s still necessary to plant them around 10cm deep.
Height x Spread: 1m x 50cm
Begonias
Begonias do especially well in pots. Choose from upright bushy begonias or trailing ones that are brilliant in window boxes and hanging baskets. Plant begonia tubers with the concave-side upwards, with the top side just 1-2cm below the soil surface.
H x S: 50cm x 50cm
Dahlias
Dahlias bear masses of large, colourful blooms over a long period, and come in an extensive choice of colours and sizes. While you can plant dahlia tubers directly in the ground outside, it’s worth getting a head start by planting them in pots under cover – not only does this result in an earlier batch of flowers but you can prevent slug and snail damage, too. Pot up the tubers with the crown around 6-8cm deep, using peat-free multi-purpose compost, then plant out into rich, fertile soil after all risk of frost has passed. Bear in mind that only single-flowered dahlias are attractive to pollinators.
H x S: 1.5m x 50cm
Lilies
Lilies are hardy summer-flowering bulbs that come back year after year, offering great value along with low maintenance. The huge flowers of lilies, borne atop tall stems and often richly scented, are real showstoppers in tubs. Plant lily bulbs 10-15cm deep. Bear in mind that Asiatic lilies need alkaline soil and Oriental lilies do best in acidic (ericaceous) soil. Hybrid lilies such as oriental trumpets, Lilium longiflorum asiatics or Lilium longiflorum orientals have less fussy soil requirements.
H x S: up to 2m x 50cm
Eucomis
Also known as pineapple flower, Eucomis has unusually shaped pineapple-looking flowers and lush strap-shaped leaves. It appears exotic and tender but tolerates a reasonable amount of frost if planted in free-draining soil. Plant the bulbs in pots with the pointed end facing upwards, around 15cm deep and spaced around 15cm apart.
Tips for success
- You can plant tender bulbs outdoors in most areas from mid-April, but wait until May if you live in a colder region. Alternatively, get bulbs started in pots under cover to plant out once all danger of frost is past.
Grow summer bulbs in a sunny and sheltered spot so they’re not blown over by wind. - Stake tall-growing plants like dahlias and gladioli, ideally putting supports in place before planting, to avoid spearing the roots.
- When flowers start appearing, feed pot-grown bulbs with a high-potash liquid feed (tomato fertilizer is fine) once a fortnight.
- Overwinter the tender bulbs in pots by simply by moving to a frost-free place in autumn.
