Others such as alliums, gladioluses, montbretias, acidantheras, lilies, colchicums, and lycoruses bloom more briefly, the flowers of individuals lasting for a relatively short period. The flowering season of some—gladioluses and montbretias, for example—can be lengthened by planting bulbs every ten days or so throughout late spring and early summer. The seasons of lilies, alliums, and a few others can be extended by using several species that bloom in natural succession.
In perennial borders and mixed borders bulbs that bloom briefly can be used with delightful results. So too can kinds of longer duration, but for massing solidly in beds that are to be attractive all summer the only ones that are useful are those that give colourful displays over a long season. We shall consider these first.
Bulbs for summer bedding
Easiest of summer-bedding bulbs to grow over most of North America are cannas, dahlias, and elephants-ears. Begonias and fancy-leaved caladiums are somewhat more exacting but are highly satisfactory where conditions suit them.
Because cannas in brilliant yellows and fiery reds so often have been used inappropriately in public plantings—frequently arranged in concentric circles with edgings of scarlet salvia—prejudice has resulted that causes them to be regarded with disfavour by many home gardeners. As a result, they are not grown as frequently as their fine qualities deserve. Yet by using modern varieties, bold of foliage and gorgeous in bloom, beds can be created that rival in magnificence anything offered; and, with imagination and good taste, these can be used in just the proper places to produce stunning results.
The modern gardener also has available cannas in more subtle colours that may be used with greater freedom. Of these the ones named for familiar operas—"La Boheme," "Mme. Butterfly," "Rigoletto," and so on—are especially pleasing.
Cannas are bold in appearance and beds of them belong most appropriately in fairly large landscapes where they may be viewed from some distance; this is particularly true of the strong-coloured varieties. They are not recommended for beds six or eight feet in diameter set in front lawns that measure fifty by thirty!
Even bolder in foliage than the canna is the elephants-ear, correctly known botanically as Colocasia antiquorum but often catalogued as Caladium esculenturn. This noble aroid is grown for its magnificent leaves; its flowers are of no garden significance. The leaves have blades that measure three feet or more long and two thirds as wide and are held aloft on stalks six to eight feet high. Elephants-ears, rich green and tropical looking, are especially attractive for planting by the waterside.
Dahlias suitable for bedding are mostly of the mignon and dwarf types, which grow to a height of about eighteen inches and include the well-known "Coltness" and "Unwire" hybrids. Although these dahlias have tuberous roots like the taller kinds and can be stored in the same way over the winter, they are usually discarded after flowering and new plants are raised each year from seeds sown indoors in February. There is no reason, however, why tubers of particular favourites from among a bed of seedlings should not be saved and propagated by division or by cuttings.
Seedling dahlias vary in colour but because most have at least one open flower at planting time, it is easy to make selections for particular effects and to arrange them pleasingly. A mixed bed provides a wealth of variety and interest and the colours can generally be depended upon not to be discordant. Low-growing dahlias are splendid plants to fill beds from which tulips have been lifted.
Choicest of all summer-bedding bulbs are tuberous begonias but, alas, these are at their best only where nights are moderately cool—a restricting requirement throughout much of the United States and Canada. The cool, damp climate that favors many places on the Pacific Coast is superb for tuberous begonias, and flowers of magnificent size and quality are common there. Although decidedly tricky in the vicinity of New York City, there are places not far away—such as the Massachusetts Berkshires—where they can be grown luxuriantly, and places nearer where they can be grown very creditably.
In the hot, dry plains and prairie states where cannas and elephants-ears thrive so well, tuberous begonias are almost impossible. Wherever they can be grown with reasonable success plant them freely, making sure that they are sheltered from whipping winds, that they have some shade during the heat of the day, and that they are kept moist.
Tuberous begonias come in many flower forms including crested, camellia-flowered, carnation-flowered, and large single-flowered varieties, all of which have blooms six inches or more in diameter. Their colours range through pinks, reds, yellows, and apricots, and there are fascinating two-toned kinds as well as some with pure white blooms.
The smaller-bloomed multiflora types bear a great profusion of flowers in an equally delightful colour range. All have beautiful foliage which adds great richness to their appearance.
Fancy-leaved caladium's are admirable for summer beds in sheltered locations. They revel in high temperatures and do well in full sun or in partial shade provided the air is not too dry. The bulbs may be bought in a mixture of varieties or separately according to colour and name. They produce an excellent-growth of magnificent heart-shaped leaves, which in different kinds exhibit a great variety of colour patterns with shades of green, red, and pink as well as of white predominating; contrasting colour usually follows the veins or mottles the surface. In some the leaves are sheer even to transparency. These plants have flowers—white or coloured and shaped somewhat like those of a jack-in-the-pulpit—but they are usually hidden beneath the ample foliage. The flowers are fleeting but the foliage is so richly coloured that the absence of floral display is of no particular importance.
Beds for summer bulbs should be spaded and enriched with compost, leaf-mould, or humus; bone meal mixed in at the rate of a quarter to half a pound to a square yard helps too. Wait until the weather is definitely warm and settled before planting. Make sure that the plants are hardened off by having been kept outdoors in their pots for about a week before the planting date, and soak them thoroughly with water a few hours before they are set out.
Take care not to break their root balls. Plant so that the tops of the balls are covered with half an inch of soil. Pack the soil firmly around the roots and soak with a fine spray as soon as planting is completed.
Because formal beds are normally expected to be in bloom over as long a period as possible it is usual to start summer bulbs to be used in them indoors early. By this means sizeable plants in four- or five-inch pots are available at setting-out time. Camas, elephants-ears, caladiums, and begonias can be grown from bulbs planted directly outdoors, but this is rarely done for bedding purposes because too long a period must then elapse before they come into bloom.
Hardy bulbs for summer borders
In perennial and mixed borders the flush of early bulbs that concludes with tulips and Dutch and Spanish irises is followed by a brief period when few bulbs flower. During this lull the parade of alliums ( flowering onions ) that began at tulip time continues. In early June astonishing Album albopilosum opens its myriads of silvery lilac, star-shaped flowers. These are massed in globular heads that measure eight to twelve inches across and top stalks one to two feet tall.
A group of three, five, or seven spaced twelve inches apart toward the front of the border never fails to command attention and interest. At about the same time Allium Moly opens much smaller heads of clear buttercup-yellow flowers that show to fine advantage against its broad, bluish green foliage. Mass this onion where it gets part-day shade; in full sun its flowers are likely to bleach. Allium Moly starts into growth late; take care not to destroy its young shoots when digging and cultivating.
The Naples onion, A. neapolitanum, blooms at the very beginning of June. Its pure white flowers sport rosy stamens and are in loose heads on slender foot-tall stems. This graceful Mediterranean species is hardy in New York City in sheltered locations but is not reliable under winter conditions much more severe. Like the others so far mentioned, it loses its foliage when in bloom or immediately afterward and so, like them, should be set behind plants that cover the ground when it retires from view.
There are numerous other alliums, but make selections with care because a few, such as A. cyaneum, are too frail for general border planting and many others although vigorous enough are in other ways unsuitable, a common fault being the undistinguished purplish flowers that characterize so many of the clan.
One excellent species that flowers later than most and that retains its foliage from spring to fall is A. tuberosum ( sometimes offered as A. odorum). This white-flowered kind grows thirty inches or so tall, blooms in June and July, and—believe it or not—is as fragrant as heliotrope. Enjoy its scent from a little distance; if you break or bruise it, an unmistakable alliaceous odour is released. This plant increases rapidly by offsets and from self-sown seeds. It is one of the finest border alliums.
After bleeding hearts, columbines, and bearded irises have faded, richly coloured peonies, tall spires of delphiniums, day-lilies, and early phloxes make a conspicuous showing on the perennial border. At this time bulbs come again into prominence; it is in this elegant company that the first true lilies make their debut. Surely lilies are among the handsomest of all plants grown from bulbs. Species and varieties may be selected to flower one after another from June through July, August, and September. Not all are easy to grow in all localities and some test the skill of the gardener anywhere.
For border planting it is wise to restrict one's choice to kinds that grow without undue difficulty, and these are likely to be found among the ones mentioned here. A special word of warning must be sounded. Do try to secure disease-free bulbs because lilies are subject to several serious bulb-borne diseases and infected stock will not only be unsatisfactory itself but will serve to infect any healthy lilies you may have in your garden.
The candlestick lily ( Lilium dauricum) is one of the first lilies to bloom and is one of the easiest to grow. It attains a height of two feet or so and its upturned flowers, which in its typical form are bright orange-red spotted with purplish black, make bold splashes of colour in the June border. Lilium dauricum comes in several colour variations. Lilium hollandicum, a name which covers a hybrid swarm rather than a natural species, is often sold as L. umbellatum although this name rightly belongs to a western American species.
The hollandicum lilies range from one and
a half to two feet tall, are available in many fine colour varieties ranging
from deep crimson to apricot and yellow, and bloom in June. At about the
same time, a related hybrid lily, Lilium maculatum (elegans), opens its
upright goblets for their fill of sunshine. The many varieties of this
lily run through about the same colour range as those of L. hollandicum.
Madonna lilies may be set well back in the border. Sturdy stems lift their fragrant white horizontal trumpets to an impressive height of three or four feet. Success with this lily is dependent upon planting it shallowly and early ( in late summer ). Its leaves remain in evidence all winter.
Scarcely later than the Madonna is the regal lily ( L. regale). This is one of the best loved and easiest to grow of all lilies. Its funnel-shaped, fragrant flowers, mostly white, are washed with rose-purple on their outsides and are light yellow deep in their throats. Combined with stately foxgloves or planted near deep purple buddleias or Clematis Jackmanii, it forms a picture not likely to be forgotten soon. With the cool dark hues of early monkshoods, the leopard or panther lily ( L. pardalinum) offers sparkling contrast.
As many as thirty flowers grace each stem. They have recurved petals and in the typical form are bright orange spotted with reddish brown for about half their length, but many variations occur. All are lovely. About the time that such summer shrubs as vitex and caryopteris begin to flower, L. tigrinum, the tiger lily, comes into bloom with red-orange flowers thickly spotted with black, its petals stiffly re-curved.
In late July and in August Lilium Henryi also displays its pendant flowers, five to twenty on each five- to eight-foot stem. The flowers are light orange with darker spots and are distinguished by a green stripe which runs the length of each petal. In sun their colour fades; it is better to plant this fine lily where it gets a little shade. Because of its unfailing dependability and prolific increase in almost any soil, it is not one to be omitted.
Even later, when September anemones are in flower, L. formosanum blooms, each stem carrying a few very large trumpet-shaped flowers of great beauty. It is white inside and coloured with purple on the outside; the petal tips are re-curved. At this time when most of the border perennials have finished blooming and early chrysanthemums and asters are beginning to show colour, bold masses of the Formosan lily are especially desirable.
There are many other lilies including numerous new hybrids and selected forms of kinds listed above. The "Mid-Century" hybrids between L. umbellatum and L. tigrinum ( which bloom in June and July) and the "Aurelian" hybrids of L. Henryi ( which flower in July and August) are outstanding examples of fine new lilies. Check catalogs of bulb dealers for others and be bold in trying those that have originated from parents that are dependable in the garden.
For colder sections of the country queenly lilies and their more plebeian relatives the flowering onions afford the greatest number of different kinds of summer-flowering border bulbs that are surely hardy, but there are some others that should not be overlooked—colchicums, for example, which come into flower in late summer and fall and have huge crocus-like flowers of purest white, lavender-pink, pink, and rosy violet.
They are quite naked of foliage at flowering time and indeed for many weeks before they bloom; because of this they must be set among a low, permanent front-of-the-border plant such as Sedum album or creeping thyme if they are in full sun, or among ajuga or sweet woodruff if they are in partial shade. In spring their broad bold leaves come up and are attractive while they are green but become rather messy looking when they are dying down in early summer. Groups of three to a dozen, depending upon the size of the border, are effective.
A choice, late-flowering bulb for the very front of the border is Sternbergia lutea. Although not botanically related to crocuses it looks more like one than does any other flower—like a glowing, golden yellow crocus with blooms of more substance than those that bloom in spring. This species begins to flower in mid-September and continues to be attractive for a few weeks, for its blooms withstand with impunity weather that damages the more fragile colchicums and true crocuses that also flower in autumn.
For mid-August display be sure to plant the so-called hardy amaryllis, Lycoris squamigera, which is often known in catalogue as Amaryllis Hallii. It bears a close resemblance to the true amaryllis, A. Belladonna, but not to the indoor hippeastrum that is commonly called amaryllis.
Lycoris squamigera is much hardier than Amaryllis Belladonna, a bulb that is really suitable for mild climates only. The lycoris produces great masses of strap-shaped, bluish green leaves in spring; these fade and disappear by mid-June and then, two months later, stout naked stapes push themselves out of the ground and attain a height of two or three feet in a matter of days. Each stem bears from its apex up to nine lily-like flowers of superb fragrance and lovely lilac-pink colouring.
The display of bloom lasts for several weeks. Lycoris squamigera thrives in full sun or in light shade. Because it is bereft of foliage at blooming time, for good effect it must be planted with carefully selected companions that make good this deficiency. One of the most satisfactory plants to use with it is the grey-foliaged artemisia "Silver King." Other appropriate associates are the yellow bedstraw, Galium vernum, plantain-lilies, and ferns.
A little-known fall-blooming squill, Scilla chinensis, is a charming item for planting among a patch of creeping thyme or other lowly groundcover right at the front of the border. In late August and September it produces generous quantities of six- to nine-inch sterns with starry, soft pink flowers clustered along their upper parts.
Another rather unusual item is the only hardy bulbous begonia, Begonia Evansiana. This native of China lives outdoors over winter in sheltered places in New York City and perhaps farther north. It is a good border plant for partly shaded locations and is easily increased by means of bulbils that form freely on its foot-tall leafy stems. It has attractive foliage and, in the typical kind, clear pink flowers; a pure-white-flowered variety of this species, named alba, is equally attractive.
Where climate permits the year-round cultivation of more tender bulbs the assortment of summer- and fall-bloomers that may be used as permanent features in borders is increased. Among the more useful of such additions are montbretias, alstroemerias, oxalises ( notably Oxalis Bowieana), zephyranthes, cooperias, agapanthuses, crinums, and calla-lilies.
Tender bulbs for summer borders
Tender bulbs that in most parts of the country must be stored indoors over winter can be used to great advantage to add brightness and interest to mixed borders in summer and fall. Gladioluses planted in groups of from six to a dozen or more assure gay though comparatively short seasons of colour. By choosing appropriate varieties and planting dates flowers may be had at any desired period from early July until frost.
Use glads to give a lift to the border at times when there are not too many other flowers in evidence. Just when that will be depends, of course, on the particular selection of plants you grow. Just remember that glad varieties differ in the lengths of time they need from planting to bloom; the earliest varieties flower in fifty-five to sixty days, others take as long as ninety days. Dealers' catalogs indicate the approximate number of days from planting to bloom.
Glads may be had in a tremendous variety of heights, flower forms, and colours. Selections may be made to fit any colour scheme. For border planting the smaller-flowered types and the softer colourings are exquisite. Because their swordlike leaves are carried nearly vertically gladioluses have little horizontal spread; they are therefore ideal for interplanting with annuals and perennials that are too closely spaced to permit of more spreading plants being set among them.
Montbretias, which is the most popular name for a group of fine South African bulbs that the botanist now includes with Crocosmia, are close relatives of gladioluses and may be used similarly. Their colour range is more restricted, being confined to warm tones of yellow, apricot, copper, and rich orange-red, and they are more airy and graceful. Because of this they should be planted in groups of at least twelve to twenty-five, with the bulbs set more closely than those of gladioluses. From Philadelphia south montbretias are generally winter-hardy.
Tigridias or Mexican shell flowers are at least as hardy as montbretias. If you have a really sunny border and your soil is on the sandy side, plant them in small groups right near its front and enjoy vivid accents of exotic colour in high summer. How beautifully formed and charmingly marked are these shallow, broad, upturned "shells," each with three flat spreading wings. Each lasts only a day, but fortunately there is a day-to-day succession of new flowers for some time. The flower colours include soft creamy yellow, buff, orange, and red. The centres of the blooms are richly spotted with darker hues.
Summer-hyacinths or galtonias bear little resemblance to real hyacinths—at least that is true if we compare them with the popular spring-blooming kinds. Their flowers are nodding white bells arranged in handsome, loose racemes along the upper parts of three- to four-foot stalks. Planted toward the rear of the border in groups of five to nine they are of high decorative value in late July and August. Because their ample, broad, floppy leaves need a fair amount of space, plant these in fairly open spots where they have room to grow unhindered and where the soil is well drained and the position sunny.
Ismenes, basket flowers—or Peruvian
daffodils, to give them their up-to-date botanical cognomen—Hymenocallis
calathina, and its hybrids are valuable for summer show because of their
extremely handsome large blooms, pure white or pale yellow and deliciously
fragrant. They are seen to best advantage toward the fore of the border,
near masses of heliotrope or richly coloured petunias perhaps.
Plant them well back in a border that is seen from some little distance away and where you may visit them or avoid them at your pleasure. You will appreciate their fragrance more if it is adequately reduced by being wafted across a breadth of lawn or garden before it reaches you. Tuberos'es have white or creamy white flowers in rather stiff spikes that attain a height of three to four feet.
Modern dahlias afford a wealth of varieties suitable for border work. Ordinarily the huge-flowered exhibition types that the connoisseur of these handsome plants so often favours are least suitable for associating with other hardy flowers, but among less gross dahlias are many that may play not inconsequential parts in the summer border.
Select varieties from among the singles, collaret’s, pompoms, decorative, and other types that will not look foreign among other plants. The taller varieties are effective when planted in threes or pairs or even singly well back in the border. Their masses of foliage give a solidity that is valued, and their blooms, perhaps viewed against a background of evergreens or shrubbery, will be appreciated and will follow each other in long succession.
Neat, inconspicuous staking is absolutely essential. Nothing detracts from a border more than lengths of broom-handle-like supports sticking out like beanpoles, painfully evident and obviously installed in optimistic anticipation of some dahlia's future. Stakes of suitable length, one and a quarter inches square, set perfectly vertically and one to a plant, are the best solution. Tie the plants so that their natural habits are preserved; avoid bunching them like sheaves of wheat.
Low dahlias including mignon or dwarf types such as the "Coltness" and the "Unwin" hybrids are invaluable for front-of-the-border display. They need no supports and even those of intermediate height get along with none more sturdy than other border plants of like stature require.
The lower dahlias may be planted in groups of half a dozen or more. Often colours will vary within a group because these types are frequently raised from seeds in the manner of annuals.
The seedlings will usually have open flowers at setting-out time and so you can easily group colours according to your preferences. When it comes to named varieties the kinds of dahlias are legion, and new ones in great numbers appear each year. When making selections for border planting choose, if possible, from kinds you have seen growing. This is so much more satisfactory than depending upon catalogue descriptions or selecting from blooms seen at flower shows. Catalogue and flower shows emphasize perfection of individual blooms—other factors such as habit of growth and carriage of the flowers are of importance in the border.
Cannas, like dahlias, are more neglected than they should be as possibilities for the mixed border. Planted in groups of three to five ( or, in large borders more ), they are spectacular sure bloomers that can be used effectively for summer and fall colour. Their foliage is handsome. It's high time to put aside silly prejudice against these fine plants and to introduce modern varieties into the mixed border with confidence and good taste. It can be done.
Tuberous begonias, particularly the multiflora
types which are less susceptible to sun-scorch than the larger-flowered
kinds, can be used in interesting patches at the front of lightly shaded
border planting; the larger-flowered types are "naturals" for
Acidantheras, with fragrant, purple-blotched, gladiolus-like flowers, may be used in the same manner as gladioluses where the growing season is sufficiently long for them to bloom before frost. Oxalis Bowieana, with its bright pink flowers in late summer, makes a charming display planted in small patches at the very front of the border. Gloriosas are elegant twiners that have beautiful red and yellow down-turned flowers measuring fully four inches across. They are best supported by five- or six-foot-tall "teepees" of brushwood made by sticking three or four pieces in the ground in a two- or three-foot-wide circle and tying their tips together. The gloriosas attach themselves by tendrils.