Blooming Bulbs – Essential Guide to Propagating Bulbs
Blooming Bulbs – Essential Guide to Propagating Bulbs
The propagation of bulbous plants or blooming bulbs is not at all difficult. The problem comes in knowing which blooming bulbs should be increased in which way. Unlike most flowering plants which have only one or two possible means of increases, the bulbs have a variety of alternative ways of increasing themselves.
The simplest way is to raise new plants from seed, and the great majority of plants mentioned in this post produce fertile seeds, though it must be stressed that if the seeds come from a hybrid, the offspring may not be in the least like the parent plant. Seeds should be sown either in the autumn or spring following their collection. Most will take two or three years to reach flowering size.
Alternatively, bulbs and corms can be increased by dividing the offsets and growing them on, by means of the aerial bulbils which occasionally form at the point where the leaf meets the stem, or by the removal of stoloniferous bulbils (stolons are underground stems at the end of which new bulbs form). Details of the propagation of various bulbs, corms and tubers are included in the alphabetical list that follows.
To scroll down to the plant you want to view, click on the relevant link in the table of contents below:
Gladiolus-like plants, white flowers with a chocolate blotch. They should be cultivated like . A. bicolor, hardier of the two species; highly scented white flowers with a dark, reddish-brown centre, 2 feet. A. murielae: very similar, less scented: 3 feet. Both flower August till late October. Individual flowers 4 inches across. Excellent for massing. Increase by seed or offsets.
Allium is the genus to which , and also belong. The leaves of many species smell of garlic when crushed. Hardy bulbous plants thriving in sun. Mostly easy to grow. Allium albopilosum, flowers deep lilac, 18 inches, May-June. Allium caeruleum, 18 inches, flowers sky-blue, May-June. Allium cernuum, drooping pink hells, 12 inches, June. Allium moly, flowers yellow, May-June, 8-12 inches. Allium narcissiflorum, , bell-shaped rose flowers, 6-12 inches, May-July. Allium roseum, flowers lilac-rose, 12-15 inches, May-July. Increase by seed sown as soon as ripe or by offsets lifted in October.
Summer-flowering lily-like plants prized for floral decoration. Avoid breaking the extremely brittle rhizomatous roots when planting. Plant 6-8 inches deep, cover with dry straw in winter in cold areas. Full sun, a rich, sandy . May not come up the first year after planting, but usually away strongly the following year. Alstroemeria aurantiaca, 36 inches, yellow or orange flowers spotted brown or yellow. Alstroemeria ligtu, vigorous hybrids, pink, red, orange or yellow: 36 inches. Increase by seeds sown several to a pot: do not plant out for a year, then plant without disturbing the soil-ball.
Closely related to the indoor Amaryllis, which are strictly Hippeastrums. Amaryllis belladonna, leaves strap-shaped: flowers huge, trumpet-shaped borne 6-8 in a cluster on top of a stem 18-30 inches tall. Autumn. Flowers after the leaves. Plant the large bulbs in light, sandy soil at the foot of a south wall.
Anemone apennina: sky-blue flowers above pale green leaves, spring, 6 inches. Likes shade and will naturalise under trees. Anemone blanda, flowers white, mauve, pink, red or blue. Spring. Sun. Excellent planted in the same ground as autumn-flowering bulbs such as nerine or amarylli. Anemone ‘de Caen’ and Anemone ‘St. Brigid’. Both produce large, brightly coloured some rather poppy-like flowers in red, blue, pink, purple or orange with a black centre. Plant in autumn to flower in spring: plant in spring to flower in summer. They reach 9-12 inches. Anemone nemorosa. The wild wood anemone. Leaves finely divided, 3-4 inches, flowers white or pink, spring, with longer-lasting flowers. Likes shade and a chalky soil. Plant 2 inches deep and increase all types by division of the roots in autumn. For other species see the alphabetical list of plants for beds and borders.
For gardening purposes are divided into two groups, those known as ‘tuberous rooted’, and those known as ‘fibrous rooted’. Here, I am covering the tuberous rooted begonias. There is probably no other group of bulbous plants except perhaps the orchids, that can rival the tuberous rooted for sheer opulence of flower. In spite of their beauty, they are among the easiest of all plants to grow. The modern types are not species but hybrids of complex parentage.
There are two methods of cultivating tuberous-rooted begonias. They may be grown either in pots, or in the open ground. If grown in pots they should be planted inmade up of equal parts of peat, leaf-mould and sand. In the open garden they should be planted shallowly in beds or borders once all danger of frost is over. The concave part of the tuber should be planted uppermost. Plant in a semi-shaded position, sheltered from winds. For the finest flowers the plants should be well-watered at all times – so long as the soil does not become soggy. Water should be stopped at the first sign of frost and the plant then be dug up in their entirety without damaging either leaves or roots. They should be taken into a dry, frost-proof place until the roots and foliage have withered. Once this has happened the stems should be cut off an inch above the tuber and the roots shaken free of earth. They should then be stored in dry peat in a dark, frost-proof place until the spring. Potted begonias need not be removed from their pots, but watering must be stopped altogether and the plants must be kept in a dark, dry, frost-proof place throughout the winter.
Tuberous-rooted relatives of the banana, valued for the sub-tropical appearance of their large green or bronze leaves and for their flamboyant red, yellow, orange or pink, often spotted flowers. Modern plants are hybrids. Grown in the greenhouse in large pots or used as bedding plants. Start the tubers indoors, in warm temperatures in peat and increase watering gradually once leaves show. Move plants to a frame in late April or May and gradually harden off. Once the chill is off the ground plant out growing tubers in rich, well-manured bed soil when there is no danger of frost. Cannas must have full sun, really rich soil and plenty of moisture during the growing season. Lift in autumn before severe frosts begin, dry off and store in a cool, well-ventilated but frost-free place till the following season. Increase by dividing the roots or by seed, which must be soaked in tepid water for 24 hours before sowing in a minimum temperature of 20°C.
Easy-to-grow plants carrying spikes of starry flowers on 3-foot stems. Plant 4-inches deep, in good soil in sun or semi-shade. Camassia leichtlinii: flowers white, cream or blue; 3 feet. Camassia quamash; violet-blue flowers. The very large bulbs are edible. Increase from offsets.
Cardiocrinum giganteum/Giant Himalayan Lily
The most magnificent of all the . Bulb large, 6-8 inches in diameter, a foot tall: leaves oval, 18 inches long and 16 inches wide, flower stem ten feet or more high: flowers highly scented six inches long, trumpet-shaped, creamy white tinged green outside, reddish markings in the throat. Essentially a woodland plant, it will thrive in moist, woodsy soil on the north side of a fence or wall. Plant-bulbs with crowns at soil level. Flowers once, then dies, but leaves numerous offsets, which take 3-5 years to flower.
Chionodoxa/Glory of the Snow
Treasured for their brilliant bright blue flowers in early spring. Perfectly hardy; plant in any fertile soil. Chionodoxa luciliae: bright blue flowers with a white centre, 4-6 inches. Chionodoxa sardensis: gentian blue, 10 inches. Increase readily from seed.
The commonly cultivated species produce crocus-like flowers in autumn, the flowers appearing out of the bare ground. The massive leaves follow in spring. Plant July or August 4 8 inches deep in sunny, well-drained soil. Colchicum agrippinium, small flowers, pink chequered purple. Colchicum autumnale, larger flower, soft rosy-lilac, very freely produced. Var. ‘Album’, a striking white form. Colchicum speciosum, large goblet-shaped flowers, from pink to purple. Var. ‘Album’ is a white form of exceptional beauty. The hybrids ‘Lilac Wonder’ and ‘Water Lily’ have larger flowers than the species: both are striking plants. Increase by seed sown in a cold frame as soon as ripe.
Massive, highly decorative plants of tropical and sub-tropical origin and appearance. Flowers huge, trumpet-shaped, lily-like, scented: leaves strap-shaped, to 4 feet long; bulb enormous, 8 inches in diameter, 2 feet long. Plant one foot deep, preferably under a south wall. Do not manure. Crinum bulbispermum, produces a large flower in clusters of up to 20, trumpet-shaped, pale pink, veined purple inside, highly scented; leaves blue-green, early summer. Crinum x powellii: hybrid of great vigour, flowers huge, trumpet-shaped, rose-pink flowers borne 10 to each three-foot stem, late summer. ‘Alba’ a white form. Grow other species in the greenhouse. Increase by seed sown on the surface in 70°F 20°C.
Deservedly the most popular of all the spring-flowering bulbs. Bringing a flare of colour at the end of the dead season. What is not generally realised is that by careful selection of species crocuses can be had in flower from August till April. Most are hardy, and will thrive in any fertile, well-drained soil. Preferably in full sun. The following is a selection: other kinds may be found in nursery catalogues:
Spring blooming bulbs: Crocus ancyrensis: earliest of the spring-flowering species, small, long-lasting flowers, deep orange-yellow, January; Crocus chrysanthus: the parent of many of the large-flowered named sorts: among the best named forms are ‘Blue Bird’, large globe-shaped flowers, soft blue edged white; ‘Cream Butterfly’, soft creamy-yellow, very free flowering; ‘Lady Killer’, rich purple edged white, pointed petals, very early; ‘Snow Bunting’, white with purple feathering and a golden-yellow throat. Crocus tomasinianus, pale sapphire-lavender flowers with an orange centre; March, will seed itself freely and make a carpet of colour.
Autumn flowering bulbs: Crocus ochroleucus, small creamy-yellow flowers, October; seeds itself freely when undisturbed. Crocus sativus, the Saffron Crocus, bright lilac with bright red stigma, October – November. Crocus speciosus, Bright feathered lilac, September/November. Crocus zonatus, rosy lilac.
Pretty autumn-flowering cormous plants. Leaves sword-shaped, flowers, tubular, produced in large sprays, yellow, orange, red or scarlet. 2 feet. Plant 3 inches deep in sun, in any fertile soil. Lift and divide every 4 years.
The hardy cyclamen are smaller both in leaf and in flower than the indoor sorts. Best planted in bold groups under trees or in light shade, where they will seed themselves. Seed can also be collected as soon as ripe and sown while still sticky in pots stood in the ground and covered with a pane of glass until germinated: should not be transplanted until they have completed their first year’s growth. Plant shallowly, only just under the surface of the soil, except Cyclamen europeaum, which should be planted 4 inches deep.
Cyclamen dislike transplanting, and once planted should be left alone. Cyclamen atkinsii, kidney-shaped leaves, deep green spotted silvery-white, flowers crimson, pink, or white; January to March. Cyclamen europeaum round, deep green leaves red underneath, flowers crimson, August-September. Cyclamen neapolitanum flowers August to October, the flowers springing out of the bare ground, followed by the leaves. Deep pink, pale pink or white. Leaves heart-shaped, deep green marbled pale green and white: worth growing for the leaves alone. Cyclamen orbiculatum (Cyclamen ocoum). Round deep, matt green leaves: flowers crimson, pink or white, January to March Cyclamen repandum, bright crimson, April.
Two species are commonly grown: Endymion hispanicus, with 10-inch spikes of bell-shaped violet-blue flowers and Endymion non-scriptus, the wild bluebell of English and French woods, bearing bell-shaped flowers on the inner side of an arching stem. There are white and pink forms, as well as the usual blue form. Both species are easily cultivated in a woody soil in partial shade. Increase by seed or offsets.
Eranthis hyemalis. The harbingers of spring, opening their flowers, brilliant bright-yellow flowers, in mild spells any time from late December to March. 3 inches. Will naturalise in borders, or on the south side of a hedge. The plant is exceedingly poisonous.
Erythronium/Dog’s Tooth Violet, Trout Lily
Spring-flowering bulbous plants of great charm. Flowers have reflexed petals like cyclamen many have leaves spotted or blotched yellow, pink or brown. Plant 3 inches deep. Increase by seed sown in a cold frame as soon as ripe or by offsets: some species readily naturalise. Erythronium dens-canis; ‘Rose Beauty’ pink flowers, ‘White Splendour’ pure white flowers, both 3 inches, March – April. Erythronium californicum; flowers creamy-yellow, several to each stem, 9-15 inches. Erythronium hendersonii, flowers lilac-mauve with purplish red markings at the base of each petal: 6-8 inches. Erythronium revolutum, 10-12 inches, and one of the easiest garden species, with named forms in various shades of pink, white and purple: May. Erythronium tuolumnense, flowers deep yellow on tall stems, March – April.
A large group of plants, a few of which are very spectacular in the garden. Increase by seed sown as soon as ripe in a cold frame, or by offsets. F. inzperialis: the Crown Imperial. Easily cultivated in sun or shade, in any fertile soil that is not waterlogged. Plant the large white bulb 8 inches deep, slightly on its side and surrounded by sand. Flowers borne in whorls in two or three tiers on the upper part of the stem; large, drooping and bell-shaped: yellow, orange or red; there are several named forms. F. meleagris, the Snake’s Head Fritillary, with curiously symmetrical, square-shouldered, bell-shaped flowers maroon-purple colour chequered with paler squares. Named forms include colours ranging from pure white to deep black-purple: 1 foot. Plant in damp soil in sun or shade.
The drooping white bells of the snowdrops are too familiar to need description. Galanthus nivalis is the common single snowdrop, but there is a double form, Galanthus nivalis Tlenus’ which has longer-lasting flowers twice the size. Galanthus nivalis ‘Olgae’ which flowers October – November, Galanthus elwesii flowers a little earlier, and also has larger flowers. Galanthus rhizehensis, flowers December to January.
Galtonia candicans looks very much like a ‘stretched’ version of a white hyacinth. Flowers milky-white, bell-shaped, scented, borne 15-20 on a stem 24-4 feet tall, late summer. Plant 6-8 inches deep in a warm, sunny part of the garden. Increase by seeds sown in a cold frame, or by offsets.
A large group of highly decorative cormous plants natives mainly of Africa. Although there are some 250 species, most of the plants grown in gardens are hybrids. None is really hardy, the corms needing to be lifted and stored away from frost over winter. The modern hybrids are divided into 3 groups
- the Large-flowered;
- the Primulinus;
- the Butterfly types.
will grow in any fertile, well-drained garden soil. Plant the corms 4-5 inches deep, 9-12 inches apart, in sun, in deeply dug, well-manured soil. Water well in the growing season, but never let the soil become waterlogged. Corms planted in late March will flower by the end of June. It is safer to leave planting till mid-April, though this means flowering begins a little later. If the site is exposed staking may be necessary: put the stakes in the ground when planting the corms. Do not add them later. After flowering remove the flower-spike. Do not lift plants till the leaves have turned brown. Then wash the earth off the corms, cut the foliage off an inch or two above the corm, and trim the roots back. The corm should then be dried. Once dry the old corm-husk should be pulled away, and the corm and cormlets dusted with both insecticides and fungicides before being stored in a cool, dry place, preferably in slatted shelves or boxes for the winter. The winter temperature must not drop below freezing, and the corms must not be allowed to become damp. The different varieties should be carefully labelled before being put away for the winter. Propagation is by means of cormlets which should be grown on in deep boxes until large’ enough to plant out in the open garden. Seedlings are easily raised, sown in a cold frame in April: seedlings will show great variation; most will be inferior to the parent plants, but at least they will be your own and unique. Seedlings take as long to reach flowering size as cormlets.
Gladioli are relatively new plants in cultivation, and some exciting developments are still going on.
Hyacinths are of two types, those known as the Roman (early flowering) and those known as the Dutch (large-flowering). Although among the most popular of spring bulbs, they are not the easiest bulbs to grow well, and are far more fussy than or . They need full sun, very light, sandy soil, free from stones and clay, neither too acid nor too alkaline. Given these conditions they will be among the loveliest of spring bulbs, and will flower in April. Plant 6 inches deep and 6 inches apart. Lift as soon as the leaves have withered, dry, and store in boxes in a cool, well-ventilated place until it is time to plant them again. If left in the ground they deteriorate rapidly. In any case, they appear to deteriorate more rapidly than any other large-flowered bulb.
Ipheion uniflora (Triteleia uniflora, Brodiaea uniflora.) One of the gems of spring; tufts of blue-green grassy leaves; Flowers palest porcelain blue with darker centre; April, 4 6 inches, ‘Violaceum’, almost white flowers. ‘Wisley Blue’ deeper blue. Increases rapidly by means of seeds and offsets, making dense clumps.
A large genus containing some of the best-loved of all garden plants. The common with its creeping rhizomatous root is dealt with in the section on . The plants dealt with here are bulbous. They are slender and refined plants. There are two main groups:
1. Reticulata Group, which are dwarf, early-flowering iris, and
2.Xiphium Group, which are rather larger and later-flowering.
Enchanting dwarfs, flowering January to March. Grow in full sun in sharply drained soil; I. danfordiae brilliant acid yellow flowers on 4-inch stems; January/February; Leaves spiky 12 or 18 inches; The bulb splits itself into many offsets after flowering. These offsets take 3 to 4 years to flower again, so ensure continuity of flower by planting a small number of new bulbs each season. L histrioides. The hardiest and most robust plant in this section. Striking royal blue flowers standing up well to bitter winter weather; 9 inches; January/February L reticulata. The best-known of this group. The flow-en pale sky-blue to a deep purple-blue, the outer segments crested with gold; 6 to 10 inches, February or March. All the plants mentioned may be grown in pots and brought indoors in winter.
The irises of this section grow up to 30 inches tall and flower between May and July. Plant 4 inches deep in sun in rich, well-drained soil. They form dense clumps, and are very free-flowering. The different species of this group have been freely hybridised to produce the following groups: Dutch Irises, flowering May to June; colours include white, yellow, blue, purple and mauve. Very hardy and easy in almost any soil.
Hybrids of L xiphioides, prefer rather damper soil than the others. Large flowers, up to 5 inches across, appear at the top of a slender stem and open in succession: blue, purple, mauve and white: June – July.
Blooming earlier than the others, usually in May. Each bulb produces only a single flowering stem, with a single flower at the top; the range of colours includes yellows, blues, whites and purples.
Ixia/African Corn Lilies
Pretty South African cormous plants producing brilliantly coloured flowers in June and July. Each corm produces a series of stiff sword-shaped leaves 12-24 inches long and a slender but very strong and stiff floral stem bearing 10-12 wide-mouthed flowers in the brightest shades of red, yellow, orange, pink or white: also multicolours. Plant the corms 4-6 inches deep in light, sandy soil in October or November in the sunniest position in the garden. In cold situations they should be protected from frosts until the end of March. The plants normally offered by nurserymen are hybrids.
Hardy bulbs thriving in sun or semi-shade in ordinary well-drained garden soil. The flowers are somewhat like those of a giant snowdrop. Plant in September 3-4 inches deep and 5-6 inches apart. L. aestivum, the Summer Snowflake, May, 15 inches: L. autumnale, the Autumn Snowflake, white flowers with a pink base, 6 inches, October: L. vernum, the Spring Snowflake, white flowers with green spots at the edges of the petals, 9 inches, March. L. vernum var. ‘Carpathicum’ free-flowering.
This is the true Montbretia, though gardeners tend to confuse it with Crocosmia. Montbretia laxifolia, 6-8 inches, sprays of cream or pinkish flowers during September and October. Plant the corms 4 inches deep in a sunny, well-drained part of the garden.
Colourful spring and early summer-flowering bulbs valued because they are inexpensive, easily grown and can be relied upon to put up a good show year after year. Planted 3/4 inches deep in October in any fertile soil. Increase by seeds or offsets. Muscari botryoides, The Grape Hyacinth, azure blue, spring, 8 – 12 inches. There are white and pale blue forms. Muscari comosum, the Feathered Grape Hyacinth, late spring, 8-12 inches, violet-blue flowers with a tuft of sterile flowers at the top of the stem: a fascinating curiosity. Muscari moschatum, the Musk Hyacinth, spring, 8-10 inches, flowers yellow or purple, strongly scented.
Beautiful autumn-flowering bulbs, prized for their iridescent pink flowers which appear out of the bare earth in September–October. Plant five inches deep (deeper on sandy soils) at the foot of a south wall; and give a mulch of well-rotted manure after the flowers. They take two years to flower again after planting. Old clumps losing their vigour should be broken up and replanted in August. Leaves strap-shaped. Hardy species include Nerine bowdenii, the one most frequently grown, 15-18 inches, deep pink: there are named forms in different shades of pink, the best being Tenwick’s Variety’.
Only one species, Schizostylis coccinea, is grown, but there are several forms. Leaves sword-shaped 1-2 feet long, flowers bright crimson, disc-shaped on a floral stem up to 2 feet high: ‘Major’ larger flowers; Mrs, Hegarty’ pale pink flowers; ‘Viscountess Byng’ palest shell-pink. Plant shallowly in rich moist soil, preferably at the foot of a warm wall; flowering September till December. Increase from offsets lifted in March.
The Siberian squill, Scilla sibirica is among the bluest of blue-flowered plants, producing a pyramid of little flowers on 3-inch stems in March. Plant 2-3 inches deep in a sunny spot, where it will seed itself freely. Scilla tubergeniana lighter blue flowers, taller growing. Increase by seed or offsets. Other species are occasionally offered in catalogues.
Small cormous plants closely related to Ixias and Freesias. Plant in well-drained soil in full sun in autumn and protect with a covering of dry straw until March. Flowering May/June, Flowers brilliantly coloured, 1-2 inches across in shades of reds, yellows, oranges and whites, with different-coloured markings in the centres of the flowers. Increase by division in late summer.