Unusual and overlooked: Summer bulbs offer something different
The profusion of flowering plants in the summer months sometimes eclipses summer-flowering bulbs. Competition from perennials, annuals and shrubs conspires to keep these cousins of the tulip, narcissus and crocus far less well known. Yet, depending on location, they can function nicely as either a focal point or a supporting feature for existing perennial plantings. Here is an overview of some of the most reliable and attractive summer-flowering bulbs.
A tropical delight-spring-planted bulbs Most summer-flowering bulbs come from warm regions of the world-the Mediterranean, South America and South Africa-and so, in general, they prefer a sunny location and are sensitive to frost. Many thrive in tubs and containers but, as you might expect, they do not overwinter in colder regions.
Summer-flowering bulb flowers often have a unique-even exotic-appearance. A good example of this is Eucomis bicolor (pineapple plant), which takes its name from its similarity to that tropical fruit. Another tropical-looking summer bulb is the blue or white lily-of-the-Nile, Agapanthus africanus. It is happiest when pot-bound, so it's perfect for container growing. However, it also functions well as a permanent planting in warmer climates such as California and the South.
The chincherinchee (Ornithogalum thyrsoides)-primarily known as a cut flower-will bloom for months outdoors. It's lovely in combination with perennial plants such as cranesbills (Geranium spp.) and pincushion flower (Scabiosa). Other varieties of Ornithogalum also are well worth considering: O. saundersiae-the giant chincherinchee-grows to a stately 3.5 feet and flowers well into early autumn, and O. arabicum, with its distinctive black center, reaches 12 to 32 inches in height.
Gladiolus callianthus 'Murielae' (formerly known as Acidanthera bicolor or Abyssinian gladiolus) and Crinum powellii smell heavenly. Thus, you can best take advantage of them by planting them near benches or other seating areas. In addition, C. powellii puts on a spectacular floral display in mid-summer. Locate it in as sunny a place as possible, preferably in a container. Likewise for Nerine undulata, with its pink candyfloss flowers that bloom later in the summer through early fall.
The summer hyacinth, Galtonia candicans, with its imposing 4-foot plume of creamy-white bell-shaped flowers, prefers a sheltered spot with some moisture.
Canna, or Indian shot, is a summer bulb with a Mediterranean look. It is gorgeous in the back of a sunny border where its flowers, which often reach more than 3 feet in height, show to best advantage. Also, Canna is a strong eye-catcher as the centerpiece in an island planting or the focal point of a large container. The showy "dinner plate" and cactus varieties are among the best-known dahlias. Less recognized is the delightful little 'Mignon' type. Standing just 12 to 20 inches tall, it will provide months of flowering, especially if you deadhead it faithfully. Use it in long, narrow containers sunk directly into the border.
Even in a small area, you'll achieve striking effects with large groups of plants. Repeating the same color creates a strong visual impression. Some color companions to consider include dahlias, begonias, montbretias (Crocosmia), gladioli and calla lilies (Zantedeschia) in many shades of yellow. Or, refresh the yellow by combining it with white: for example, Gladiolus callianthus 'Murielae', dahlias and the pineapple flower (Eucomis autumnalis ssp. autumnalis).
Many perennials come in pastel hues, and summer bulbs complement them nicely. Combine pink tree mallow (Lavatera) with a dahlia of the same color. In blue-violet, team up lily-of-the-Nile with larkspur (Delphinium spp.).
Oxalis deppei has daintily marked leaves and pinkish-red flowers. Combine it with other types-such as O. triangularis, which has dark-purple leaves and pink flowers, and O. regnellii, with its tiny moss-green leaves and white flowers-for an interesting combination of colors and textures.
Autumn-planted bulbs Although you plant most summer-blooming bulbs in the spring, some-such as lilies and alliums-actually require planting in the fall. You should plant all of the following bulbous plants in autumn along with the usual spring-flowering bulbs.
One of the most regal of the summer bloomers is Eremurus (foxtail). Bearing deep-pink flowers in June, Eremurus robustus definitely pays homage to its name-the flower spike can grow to between 6 and 9 feet. Other Eremurus species such as E. stenophyllus (lemon-yellow) and E. himalacus (white), as well as the Shelford hybrids (a mix of orange, yellow, cream and pink flowers), stand about 3 feet tall, so a location sheltered from the wind is preferable. As their common name-desert candle-might suggest, they like as much sun as possible. Plant their starfish-like bulbs in autumn and so shallowly that the "nose" almost sticks up above the surface of the soil. Loamy, rich, permeable soil is ideal.
Site Eremurus near intermediate-size shrubs such as Philadelphus (mock orange), Ceanothus (California lilac), Spirea and Viburnum. It also makes a good neighbor for large groupings of mid-height perennials such as irises, Lysimachia (loosestrife) and Centranthus (red valerian).
Camassia flowers a few weeks before Eremurus and looks similar to it, but not as massive. The smallest species, the bright-blue Camassia esculenta stands about 1.5 feet high. The others, C. cusickii and C. leichtlinii, are about twice that height. Their flowers may be light or dark blue, or white. All species of Camassia prefer a somewhat damp soil, so clay is ideal. They are most attractive in informal settings or by a body of water where their decorative flower spikes can emerge over impressive foliage such as that of Rodgersia or the fine lacework of ferns.
* Allium. Alliums include a large number of species and represent a major component of your summer-bulb palette. When it comes to locations for allium, no hard-and-fast rules apply. Allium stipitatum 'Album', bearing creamy-white flowers and standing about 3 feet tall, can withstand some shade. It looks exquisite among groups of blue-flowering geraniums and yellow-green lady's mantle (Alchemilla mollis). As an added bonus, after flowering, this allium forms slender seed pods that last for months atop their sturdy stems.
Allium sphaerocephalon favors a warm dry spot. This variety, commonly called "drumsticks," bears reddish-purple flowers and reaches a height of about 1.5 feet. It combines well with lavender, Artemisia and low-growing ornamental grasses.
Allium karataviense, a sun-lover that prefers dry, rocky locations, makes a good companion for thyme, Cerastium (snow-in-summer) and various low-growing species of Sedum (stonecrop).
Two of the most impressive are Allium giganteum and Allium 'Lucy Ball' (a cross between A. aflatunense and A. macleanii). Both are striking because of their height-at least 3 feet-and their big, lilac-colored flowers that measure some 6 inches across (see photo, top of page C 6). In addition, 'Lucy Ball' has a delightful scent.
Allium schubertii boasts an extremely unusual flower structure. It is actually a "double," making it decorative after, as well as during, its flowering period. However, it is not completely winter hardy, so mulch it well. All of these alliums prefer a warm, dry location and flourish in the company of perennials such as poppies, Lavatera, Artemisia, Lavandula (lavender) and Gypsophila, which require the same conditions. Most allium leaves wither unattractively, so plant alliums among perennials that have ornamental foliage to camouflage their bare stems. Remove the allium foliage after it has withered-the bulb will have matured by that time.
Plant allium in early October: the small bulbs at a depth of just an inch or 2, the larger varieties with at least 4 inches of soil covering them.
* Lilies. Although lilies-those showy and elegant flowers of the genus Lilium-often are grown for exhibition and cut flowers, they do well in many sites, including woodlands and natural areas, as well as among shrubs or herbaceous plants in the border. Most lilies are slow starters, growing best when left undisturbed in the same spot. However, they last for many years, and age seems to improve the richness of their flowering.
Lilies are no "shrinking violets." Hardy survivors, lilies actually require a cold dormant period to thrive. In Zones 9 and 10, you must give all lilies a few weeks of refrigeration before planting them in autumn. Asiatic and Martagon hybrids can grow well in regions as cold as Zone 3, while most other lilies survive in Zone 4 and up.
Many of the most popular lily varieties are hybrids from the Asiatic, Oriental, Longiflorum and Trumpet divisions. They all have similar flower shapes, and both species and hybrid lilies come in a vast array of colors (white, yellow, pink, red, orange and variations of each).
Many lilies are beautifully scented. For instance, Longiflorum hybrids (for example, the so-called Easter lily); Trumpets and Aurelian hybrids (such as 'Black Dragon' and 'Golden Splendour'); and Asiatics (the orange 'Elite', the yellow 'Novo Cento' and the white 'Navona') all produce pleasant scents. The most strongly scented of all, however, are the Oriental hybrids, such as 'Casa Blanca', 'Star Gazer' and 'Le Rve'.
Plant lilies in combination with evergreen ground covers to brighten up a monotonous patch with color and scent throughout the summer. Remember, lilies like to have their "heads in the sun, feet in shade," regardless of location. These perennial plants also are amenable to growing in large containers. Regardless of the site, they require nutrient-rich, moist soil.
Carol J. Sutton (Vancouver, B.C.) is a communications consultant for Plant Publicity Holland, which represents Dutch growers, wholesalers and exporters.
Want to use this article? Click here for options!
© 2016 Penton Media Inc.