Choosing and growing spring bulbs
Success with bulbs means planting fat, firm bulbs (discard any shrivelled or mouldy bulbs), in the right conditions, and at the right depth (generally, 3 times the depth of the bulb). All bulbs need well-drained soil; if your soil tends to lie wet in winter, add grit to the planting hole. The one exception is beautiful, chequered snakeshead fritillaries, which tolerate quite wet soil, and thrive in damp meadows.
Bulbs (daffodils, snowdrops, netted iris), corms (crocus), tubers (winter aconite) and rhizomes (lily-of-the-valley, anemonies) are perennial, coming back year after year. Tulips are rather different – species tulips may perennialise, but the big, glamorous cultivars are less likely to do so. Tulips are different in other ways, too, and I’ll deal with them in a separate section.
Naturalising bulbs in grass
Naturalising in grass is suitable for reliably perennial bulbs and corms like daffodils (Narcissus), crocus, snowdrops, grape hyacinths and Cyclamen coum. Plant them where grass is allowed to grow long, as the bulbs must be allowed to die down naturally before the grass is mown (this also conceals the unsightly dying leaves). You can mow six weeks after the last flowers go over, but the longer you can leave it, the better it is for wildlife. Mow in November, so that the smaller bulbs show up well. A particularly good site is the grass under deciduous trees, like fruit trees, as most bulbs have evolved to flower early in the light coming through the leafless branches, but prefer light shade in summer. The soil will usually be humus-rich, which bulbs like.
Choose reliably naturalising bulbs – species or large-flowered crocus, and the simpler daffodils and snowdrops rather than the double forms; check the website for which cultivars will naturalise well. Mixed bags will give you a blaze of varied colour, while patches each of one cultivar will look more natural. Plant in September for best results. If you’re planting a big area, it’s worth getting a long-handled bulb-planter – a hand bulb-planter will be fine for smaller spaces. To give a natural effect, throw the bulbs down and plant them where they fall, more thickly in the middle of the group, more scattered at the edges. Most bulbs should be planted three times the depth of the bulb, no deeper. Then use the bulb-planter to take out a plug the right size, add grit if necessary, drop in the bulb, pointed end up, and replace the soil and patch of sod. When planting little bulbs, you can remove a section of the sod, fork over the soil, scatter the bulbs, and replace the sod, watering in well.
Planting ‘in the green’
There are some bulbs which establish better when planted ‘in the green’ in spring (in active growth) than from dry bulbs in autumn. Snowdrops and bluebells establish reasonably well from bulbs, though better ‘in the green’, but cheerful winter aconites and lily-of-the-valley (from ‘pips’) do much better bought ‘in the green’.
Bed and Borders
There are some really striking perennialising bulbs to light up a border in May, before late summer perennials start to shine. Tall, upright crown imperials (Fritillaria imperialis), with a collar of brick-red or bright yellow bell shaped flowers under a pineapple tuft of leaves look marvellous in a formal garden; plant them in full sun. Tall camassias (Camassia leichtlinii), violet-blue and creamy-white, have a softer look, beautiful in a herbaceous border, and will tolerate partial shade. Ornamental onions (Allium), which flower in May and June, are also lovely in borders; they prefer full sun, but tolerate a little shade, and can be planted any time in autumn. Their dying foliage will be hidden by the foliage of late-flowering perennials, and their seed-heads are ornamental. Borders are also the place for the gorgeous double and split-corona daffodils, which will happily come up year after year, if planted in sun or very light shade in fertile, well-drained soil. Plant all these as early as possible, preferably in September, and no later than November.
Also lovely at the front of a border are ‘the little blue bulbs’ – violet-blue scillas like tiny bluebells; starry Chionodoxa luciliae, glory-of-the-snow, blue with a white eye; scented, dwarf Iris reticulata Harmony; violet crocuses like Flower Record; Muscari latifolium; and the Greek windflower, Anemone blanda (which comes in other colours, and can also be naturalised in short grass). These look lovely with dwarf daffodils, like the ever-reliable Tête à Tête, or its double form, Tête Bouclé, or white Toto. Mixed bags of dwarf daffodils are also available. Crocuses need full sun, the others will also tolerate partial shade. Double snowdrops are also lovely in beds, and need partial shade. All these early bulbs should be planted in September, if possible, for best results.
Tulips must be planted in full sun in very free-draining soil, and should not be planted until November to prevent the fungal disease tulip fire (by Christmas at the latest).
Apart from species tulips, and the cheerful red and yellow Darwin types which will last for five years, most tulips don’t perennialise well. They are more likely to perennialise if planted 8” deep in a border, which discourages the bulb from splitting into bulblets, which will not flower for years. Some of the singles, doubles and Triumphs are better perennialisers than others, but generally need topping up each year. This means the older bulbs come up a little earlier and smaller, giving a subtle, less regimented effect when the new bulbs join them.
Tulips are often grown as annuals. They work well as bedding, yellow ones over a froth of forget-me-nots, pinks over grape hyacinths, or deep purple with frothy white alliums. Alternatively, grow them massed, mixing and matching: pinks, purple, pink and purple-streaked white, a blaze of yellow, orange and scarlet, or smart purple-black and white.
Almost all hardy bulbs are great in pots, and can be layered in larger containers, with the latest to flower at the bottom, and the little early bulbs at the top.
Gorgeously scented hyacinths and paperwhite narcissus can be forced to bloom in time for Christmas. Paperwhites are not hardy enough to be planted outside afterwards, but hyacinths can, growing less top-heavy in subsequent years.
To preserve vigour, dead-head daffodils and tulips to below the bulge under the dead flower, leaving the stem, but allow crocuses and snowdrops to set seed. All bulbs should be let die down naturally to nourish the bulb, so it flowers well the following year.
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- Maria Collard