Summer Flowering Bulbs
Bulbs, corms, and tubers to plant in the spring and to look forward to in summer and early fall
Pictured: Gladiolus sp.
When most people think of bulbs they think off tulips and daffodils, which are planted in the fall and bloom in spring. Often overlooked is the myriad of summer-blooming bulbs (and those that are associated with bulbs, such as tubers, corms, and tuberous roots) that can be planted in spring. These plants differ from fall planted bulbs because they do not require an extended cold dormancy period.
Know Before You Grow
When deciding where to place summer-blooming bulbs in your garden you will want to do some homework before heading to the garden center. There are summer blooming bulbs that are hardy and you can expect them to perennialize (lilies/daylilies, Crocosmia, Nerine, Agapanthus, Hosta and Convallaria). There are also summer blooming bulbs that are more tropical and will not overwinter reliably (Dahlias, Gladiolus, canna lilies, calla lilies, Eucomis, Freesia, and Acidanthera).
Planting - Aim to plant bulbs right side up. The roots should be on the bottom of the planting hole. Check to see if there are any roots attach to the bulb, they’ll be growing from the bottom of the bulb. Some tubers have a cup shape and the concave bowl of the cup is usually the top side. If you see tiny sprouts of new growth take care to not break these. As a general rule of thumb, plant bulbs at a depth equal to two to three times the thickest part of the bulb.
Staking - Many summer flowering bulbs (especially Dahlias and Gladiolus) benefit from staking. This is best done at the time of planting to avoid accidentally spearing the bulb later.
Spacing - Summer bulbs look best planted in drifts or clusters. Avoid planting them in rows, unless you’re planting in a more traditional cut-flower garden.
Temperature: Summer blooming bulbs that are perennial can be planted first. Heat loving perennials, like Agapanthus, are best planted when soil temperatures have started to warm up. Tropical or non-perennial bulbs prefer the warmest temperatures, and shouldn’t be planted in the ground until the risk of frost has passed.
Our Top Summer Flowering Bulbs
Dahlias - Dahlias are one of the most common summer flowering plants. They make a great cut flower, and there are endless flower forms and colours to choose from. Check out the dahlias we grow here, and our tips on overwintering Dahlias here. Not hardy.
Gladiolus - This classic cut flower is enjoying a renaissance as it’s soft-hued varieties like pale green and apricot are very popular right now. Orchid-shaped blooms appear atop three to four foot stems. Gladiolas grow best in fertile, well-drained soil with consistent moisture. The corms should be planted with the pointed side facing up and a little deeper than the recommended three- or four-inch depth to help keep the stems upright once the flowers begin to open. Not hardy.
Picture: Calla Lily
Lilies/Daylilies - Lilies are hardy perennial bulbs that can add fun and drama to your garden. There are many varieties to choose from: Asiatic, double Asiatic, LA Hybrid, Trumpet, Oriental, and OT Hybrid forms. Perennial.
Calla Lilies - Although not a true lily, these exquisite flowers have long been favourites of gardeners and floral designers. Large, funnel-shaped blooms form from a single luminous, waxy leaf. Flowers bloom in shades of classic white, yellow, orange, pink, rose, lavender, and dark purple-plum. Plant them in full sun or partial shade. They prefer lots of moisture. Not hardy.
Canna Lilies - Canna lilies are a great way to add height and dimension to your garden. These tropical looking flowers bloom in colours of red, yellow and orange and can grow to five- to seven-feet in height. The bold leaf patterns and hot flower colours make this a perfect summer plant for the poolside or tropical terrace. Not hardy.
Acidanthera - Growing from small corms this summer-blooming relative of the gladiola produces fragrant, graceful white flowers on slender stems. The blossom have a distinctive, dark-purple mark at the throat of each nodding flower. These plants should be grown in full sun and planted after the soil has begun to warm. Borderline hardy.
Eucomis - This summer-blooming bulb has unusual flowers that inspired its common name: pineapple lily. The long, strappy leaves may be green or burgundy. Stems are sometimes freckled with purple. Eucomis flower colors come in white, pink and violet. Eucomis is a great plant for tropical displays, with it’s long-lasting flowers and tropical foliage. Not reliably hardy.
Pictured: Nerine sp.
Agapanthus - Shooting up from the low herbaceous clumps, stunning blue, purple, or white globe-shaped flower clusters hover atop tall stems. Slow to flower after being planted (up to three years) this plant makes up for it by it’s toughness in hot climates, excellent cut flowers and penchant for growing in pots. Prefers full sun and regular moisture though can tolerate minimal water established. Perennial.
Nerine - This bulb can be purchased and planted in the spring as a bulb for beautiful vibrant pink flowers in fall. The bulbs burst into bloom in early fall when most other flowering plants are fading away. The bulbs should be planted near the surface as they like to be baked by the summer sun. Nerines have narrow, strappy, slightly floppy leaves. These leaves emerges from the bulb in early summer and die back in early fall, just before the flowers start to bloom. Grow in full sun to partial shade for best results. Perennial.
Honorable mentions
Anemone
Crocosmia
Freesia
Peonies
Hosta
Lily of the Valley (Convallaria sp.)
Top Summer Flowering Bulbs for Wet Soil
Canna lily
Elephant ear (Colocasia sp.)
Calla lily (Zantedeschia sp.)
Perennials: Spiderwort (Tradescantia sp.), Leopard plant (Ligularia sp.), Hosta, Astible
Top Summer Flowering Bulbs for Shade
Elephant Ears (Colocasia sp.)
Calla lily (Zantedeschia sp.)
Caladiums
Tuberous begonias
Perennials: Hosta, Pulmonaria, Astilbe, Lily of the Valley (Convallaria sp.), Wood anemones (Anemone nemerosa)
All of these bulbs are available for purchase in spring.
