Elementary Summer Bulbs

A revamped website offers a summer bulb primer just in time for you to add some sass, color and class to your summer garden.

Begonia bertinii

Begonia bertinii (pendulous begonias) is among the top 10 summer bulbs from the Netherlands Flower Bulb Information Center's Summer Bulb Primer.

courtesy Netherlands Flower Bulb Information Center

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Summer is gardening’s crowded hour. So many perennials and annuals thrive in that season’s sun and heat that it can be easy to overlook the role that flower bulbs play.  Most gardeners are familiar with tulips, daffodils, hyacinths and other bulbs that dominate the spring landscape. But there is another class of bulbs entirely comprised of summer bloomers. These include some of the most exotic flowers found in any garden, and spring is the time to plan and plant them.

Summer bulbs include Oriental lilies, gloriosa and a wide range of dahlias that are literally flower factories. 

“You might expect such stellar plants to be hard to grow,” says Sally Ferguson of the Netherlands Flower Bulb Information Center (NFBIC) in Danby, Vermont.  “The surprise is that they’re not at all tricky.”

As an introduction to these savory summer flowers, the NFBIC has created a new Summer Bulb Primer on its informational website. The Primer is a photo-filled, information-packed resource that profiles the top 10 bulbs for the summer garden that are available from garden retailers as either DIY bulbs or as “ready-to-go” pre-grown potted bedding plants. 

The primer includes such exotic garden treats as climbing gloriosa vines, tufted tropical-looking pineapple lilies (Eucomis), multitudes of tall and short leafy cannas, new colorful callas (Zantedeschia) with metallic-spotted leaves, flamboyant fragrant lilies, bountifully- blooming begonias, big-leaved elephant ears, oodles of oxalis and caladiums, and dahlias of all types and coloration.  All are suited to garden beds and summer containers.

Most summer bulbs are tender by nature and cannot survive cold winters without protection.  Depending on where you garden, summer blooming bulbs can be grown as annuals or perennials – or something in between.  In warmer USDA zones, summer bulbs in the garden will readily come back as perennial performers. At season’s end in cooler areas, gardeners can choose to save summer bulbs for growing again in future seasons. Where winter exposure is an issue, lift and store bulbs indoors overwinter.  Even easier, bulbs grown in containers can be stored over-winter “as is” (right in their pots) in a protected area. Just cease watering until it’s time for start-up next season.

Even so, saving bulbs is optional, a benefit, not an obligation.  Likewise, don’t let “where you live” limit which tender summer bulbs you grow.  In summer, tender bulbs will grow most anywhere.  In hotter areas, even cool-loving dahlias can thrive if provided with mulch and afternoon shade. In colder zones, the most outrageous, heat-loving tropical plants fare beautifully if protected from cold at the growing season’s beginning and again at its end.

To get started with summer bulbs, make a quick visit to the Summer Bulb Primer.  To take things to a higher level, see the Summer Bulb Glossary on the website. The website has recently been revamped and updated. It’s full of easily accessible information on summer bulbs, spring bulbs plus potted and cut flower decorating tips.

Here’s a quick look at the top 10 summer bulbs covered in the Primer. All are readily available from garden retailers as bare bulbs or professionally pre-grown potted plants  for instant color.

• Begonias – Most bulb plants love sun, but begonias are shade dwellers and one of the few that bloom so exuberantly in low-light settings. Short in stature, begonias have large dense flowers with ruffled petals in rich shades of red, yellow, white, champagne, pink, or orange.

• Caladium – Another shade lover, caladiums are known for colorful “painted” heart-shaped leaves in mixes of greens, whites, pinks or reds. Some are solid colored, others sport spots, flares or blushes. Caladiums can handle more sun if kept well watered.

• Calla (aka Zantedeschia) – A romantic choice for bridal bouquets, calla lilies were once available primarily in white or softest pink. Today, these lovely summer flowers are also available in red, orange, yellow, rust, lavender, pale green, gold, purple and near-black. In the garden or the vase, the calla’s chalice-shaped flowers and luxurious leaves are elegant and long-lasting. Grow in full sun to partial shade.

• Canna – Cannas are garden peacocks, strutting their magnificent foliage. They come in dwarf (18 to 36 inches, 45 to 90 centimeters ) and tall (3 to 12 feet, 90 centimeters to 3.5 meters) versions. Their broad leaves in shades of green, brown, burgundy, black and multicolored stripes are so dramatic that their fluttery flowers seem irrelevant. Still the flowers are an added treat, worn aloft like little cocktail hats. Grow in full sun, also suited to water gardens, if desired.

• Dahlia – Razzle-dazzle dahlias are the surprise of the decade. Once pooh-poohed by the genteel set for their raucous colors and exuberant shape shifting, dahlias today are prized for these same traits. Count on dahlias to anchor the late season garden, blooming their hearts out, till frost slows them down. Plant dahlias in full sun. Cut flowers for the vase any time you like, but definitely snip off faded flowers. You’ll be happy you did, because the more you cut dahlias, the more flowers they produce.

• Elephant Ears – Under this moniker three elephantine-types are pooled – Colocasia esculenta, Alocasia, Xanthosoma – all earmarked by elongated, outsized, heart-shaped leaves. These tender toughies tend to transform ho-hum settings into tropical holiday havens. Different varieties have different looks, with green, chartreuse, black or striped foliage. Their heights vary widely, ranging from 12 inches (30 centimeters) to 6 feet (1.8 meters). Elephant ears like sun, partial shade, even deep shade. Suited to water gardens, if desired.

• Gloriosa – How truly odd: a summer bulb vine that pulls itself aloft by throwing tiny green tendrils from its leaf tips, its exotic flowers draped here and there like so many huge energetic spiders. Gloriosa lilies boast striking, streamlined petals so deeply reflexed they’re bent back. They are sun lovers that relish any bit of support, scrambling up a trellis or obelisk, happy to hitch a ride to another woody vine or shrub.  When the flower show is over, gloriosa keep going.  Their fat undulated seedpods provide garden interest well into fall.  Look for varieties with red-and-yellow, orange or yellow flowers.

• Lily – While most summer bulbs are frost sensitive tender bulbs, lilies are hardy perennial bulbs and can be planted in either spring or fall. They are often considered the queens of the summer garden in a nod to their regal bearing and sophisticated flowers. Many are wonderfully fragrant, to boot. Lily styles, colors and looks abound – especially now!  Lily hybridizing is hitting a new peak! See the NFBIC’s website to learn more about the new, newer and newest lililes headed to a garden retailer near you.

• Pineapple Lilies (Eucomis) – Certainly this bulb flower is reminiscent of the tufted tropical fruit.  With its 15-inch (38 centimeters) spire of tiny greenish–white (or wine-colored) flowers atop a base of broad, strappy green leaves, eucomis are decidedly dramatic.  As potted plants, they’re spectacular. After bloom, eucomis provides a stellar second show as its dried seed heads are often even more interesting than the original blossoms.  Grown in full sun or filtered light, eucomis are stars of the mid- to late season garden.

• Oxalis – Easy-to-grow oxalis looks like four-leaved clover but is much more desirable. Its low, mounded growing habit, makes oxalis ideal as an under-planting for taller plants or as a tabletop accent plant. Oxalis is prized for intriguing foliage and dainty pink or white blooms from late spring through frost. These garden-style non-invasive beauties are good luck in any garden. Look for varieties with leaves in green, purple-black or green with dark burgundy iron cross markings.

The Summer Bulb Primer is a stylish introduction to the top 10 summer bulbs available as bulbs or potted plants, with lots of pictures and how-to videos.