Growing Hardy Bulbs

Description, Botanically a bulb is built up of many fleshy or scaly segments, such as those of a lily. In this work the term hardy bulb is used more loosely to include many plants with thickened root stocks storing food to carry the plants over a dormant period. These plants are all perennials. There are also half-hardy and tender kinds.

Soil and Situation. Hardy Bulbs like hardy herbaceous perennials, bulbs are of many kinds and have varying requirements. Some thrive in shade, others in full sun, but in general most prefer open, well-drained, reasonably rich soils. Ground should be dug deeply and, if believed to be poor, should be enriched with manures such as bonemeal, basic slag, and hoof and horn, plus moderate dressings of well-rotted animal manure well worked in.

Planting. Spring-flowering bulbs are planted in late summer and autumn; summer-flowering bulbs in spring, and autumn-flowering bulbs in July and early August. Of the spring-flowering varieties, snowdrops and narcissi (daffodils) should receive first attention (August—September), while tulips and hyacinths may be left until last (October—November). Daffodils and Narcissi - Narcissus

Planting may be done with a trowel, stout blunt-ended dibber, or spade. Never plant with a pointed dibber, as this may leave an air space Beneath the bulb. A special tool can be obtained for planting bulbs in grass.

Most lilies may be planted in autumn when dormant or they may be moved in March or April like herbaceous perennials. Exception must be made for Lilium candidum (the Madonna lily) and L. testaceum, which should be planted in late July or early August. Moreover, these lilies and also L. giganteum are only just covered with soil. Stem-rooting lilies are planted most deeply, though often the holes are only half filled at first, more soil being added as the stems grow.

Gladioli should be put in successionally during March and April to prolong the flowering season.

Cultural Routine, Beyond hoeing and weeding there is little that can be done while bulbous plants are in growth. Tall-growing kinds, e.g. lilies, or those with heavy spikes of blooms, e.g. gladioli, will require staking and tying. This should be done early. Some lilies form roots from the stems as well as from the bulbs. Soil may be drawn towards these while in growth or, better still, a mixture of soil and leaf-mould or peat can be spread around them in the spring to encourage formation of stem roots. Most bulbs can be fed with weak liquid manure or a general fertilizer applied during the spring for spring-flowering kinds and during the early summer months for gladioli.

Lifting and Storing Hardy Bulbs. Spring-flowering bulbs may be lifted after the foliage has died down in summer. This will be in June or early July for narcissi (daffodils) and early tulips and in late June or early July for late tulips, hyacinths and Spanish, English and Dutch irises. In no case should foliage be removed before these times. If bulbs must be lifted earlier, they should be replanted (heeled in) at once, close together in trenches, to complete their growth.

After lifting, pull or cut off the dead leaves, sort the bulbs into sizes, place in shallow boxes, and store in a cool airy place, but not in full sunshine, until planting time. Small bulbs will not as a rule flower the following year but may be planted in a reserve bed to grow on.

Gladioli are lifted in September—October, about six weeks after flowering. Cut off the leaves at once about an inch above the corms (bulbs). Then remove and discard the old withered corms at the base of the new plump corms. Remove tiny cormlets which can be grown on to flowering size if desired. All are stored in shallow trays in an airy, frost-proof place.

Montbretias may be treated in the same way as gladioli, but it is better not to allow them to become fully dormant. Instead, lift in early November and replant close together in a frame, watering very moderately during the winter.

It is not necessary or desirable to lift and store all bulbs every year. Gladioli must come up because they are tender; tulips and hyacinths usually benefit from lifting. Lilies should be left undisturbed unless overcrowded, diseased, or in other ways in need of removal. Crocuses, snowdrops, muscari, bulbous irises, and narcissi (daffodils) can generally be left for several years undisturbed until a falling off in quality and quantity of bloom indicates overcrowding.

Propagation. Most bulbs can be increased by removing offsets or young bulbs which are formed alongside or above the old ones. This should be done at the usual lifting season and the small bulbs should be replanted exactly like the large ones but at about twotthirds the depth and in a separate bed, as they will not flower the first year. Some kinds also make tiny bulbils or cormels; certain lilies have these bulbils in the axils of the leaves, while gladioli carry them round the new flowering corm. Like small bulbs, they must be grown on to flowering size but will take longer to attain this, possibly two to four years. Treatment is the same as for bulbs except that they must be covered with approximately their own depth of soil.

Bulbs can also be raised from seed sown in a frame or sheltered position outdoors in March. Choice varieties of lily, etc., are best sown in pans and germinated in a cool greenthouse. The seedlings are left undisturbed until they die down, when the tiny bulbs are unearthed and treated like bulblets or cormels.

Most lilies can also be propagated by scales. These should be pulled from mature bulbs during the summer (July—Sept.), and laid fairly closely in trays half filled with peat moss or leaf-mould and sand. Cover with half an inch of the same mixture, moisten and keep in a cool place. Bulbs form on the scales and can be treated like bulblets or cormels.

A table of Hardy Bulbs

Note—Figures represent months e.g. 3 = March

Botanical, Popular Name, Colour, Flowering Season, Height, Depth, Planting Time

  • Acidanthera — White and maroon, 8-9 3 ft. 3 in. Apr.-May
  • Allium Various, 5-7 1-4 ft. 4 in. Autumn
  • Amaryllis Belladonna Lily Pink, 9-10 2-3 ft. 4-6 in. Aug.
  • belladonna
  • Anemone (St Windflower Various, 4-7 9-12 in. 2-3 in. Oct.-Apr.
  • Brigid, Du
  • Caen, fulgens)
  • Antholyza — Orange, 8-9 3 ft. 3 in. Mar.-Apr.
  • Calochortus Butterfly Tulip Various, 5-6 1-2 ft. 3 in. Oct.-Nov.
  • Chionodoxa Glory of the Snow Blue, 3-4 4-6 in. 3 in. Autumn
  • Colchicum Autumn Crocus Various, 9-10 7-8 in. 1 in. Aug.
  • Convallaria Lily of the Valley White, 4-5 6 in. 1-2 in. Nov.-Mar.
  • Crinum White pink, 8-9 3-4 ft. 9 in. Mar.
  • Crocus — Various, 10-3 3-6 in. 3-4 in. Aug.-Oct.
  • Cyclamen — White to crimson, 10-5 4-6 in. 1 in. Aug.-Sept.
  • Eranthis Winter Aconite Yellow, 1-2 2 in. 2 in. Autumn
  • Erythronium Dog’s-tooth Violet Various, 3-5 6-12 in. 3 in. Autumn
  • Fritillaria Crown Imperial Yellow, red, 5 2-3 ft. 4-5 in. Autumn
  • imperialis
  • Friallaria Snakeshead Fritillary Various, 4-5 6-12 in. 2-3 in. Autumn
  • meleagris
  • Galanthus Snowdrop White, 11-2 4-8 in. 4 in. Autumn
  • Galtonia Spire Lily White, 7-8 2-3 ft. 6 in. Autumn
  • Gladiolus — Various, 6-9 2-5 ft. 4 in. Mar.-Apr.
  • Hyacinthus Hyacinth Various, 4-5 9-15 in. 5-6 in. Oct.-Nov.
  • Iris (bulbous rooted) — Various, 1-7 1-21 ft. 3 in. Autumn
  • lxia — Various, 6 2 ft. 2 in. Autumn
  • Leucojum Snowflake White, 1-5,10 4-18 in. 3 in. Aug.-Sept.
  • Lilium Lily Various, 6-9 11-12 ft. 1-8 in. Autumn
  • Montbretia — Yellow to crimson, 8-9 2-3 ft. 2-3 in. Mar.-Apr.
  • Muscari Grape Hyacinth Blue, 4-5 4-8 in. 2-3 in. Autumn
  • Narcissus Daffodil White, yellow, orange, 4-24 in. 3-6 in. Autumn
  • Ornithogalum Star of Bethlehem White, 5-6 1-11 ft. 4 in. Autumn
  • Puschkinia — Blue and white, 4 6 in. 3 in. Autumn
  • Ranunculus — Various, 5-6 9 in. 2 in. Nov.-Mar.
  • Schizostylis Caffre Lily Pink, scarlet, 10-11 18 in. 3 in. Mar.-Apr.
  • Scilla Squill, Bluebell Blue, white, pink, 3-6 3-15 in. 3-6 in. Autumn
  • Sparaxis Harlequin Flower Various, 5-6 1 ft. 2 in. Autumn
  • Sternbergia Lily-of-the-Field Yellow, 10-11 4 in. 4 in. Aug.
  • Tigridia Tiger Flower Various, 7-8 18 in. 2 in. Apr.-May
  • Tulipa Tulip Various, 3-5 6-30 in. 4-5 in. Autumn
  • Watsonia Bugle Lily Various, 8-9 3-4 ft. 3 in. April

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