Planting bulbs ‘in the green’ - by Deborah Ballard
Some bulbs, tubers and rhizomes are better planted ‘in the green’ – in spring, when they are still in active growth – rather than as dry bulbs in autumn. These include winter aconites (which are particularly hard to establish from tubers), snowdrops, bluebells and lily-of-the valley. Future Forests stock these ready to send out in February and March. Plant them as soon as you receive them, preparing the soil beforehand if necessary so they can sprint away happily.
Soak the roots for half an hour if they appear dry. Using a narrow trowel or dibber, plant them in moist soil at the same depth as they grew before (where the stem turns green), although snowdrops, can be planted very slightly deeper. Space them at least twice the width of the bulb apart, if not more – they will soon bulk up into drifts and clumps. Water in well.
Snowdrops, both the delicate-looking singles and pretty, frilly doubles, establish very easily in the green, and are lovely in woodland plantings and in drifts in borders; they can even be naturalised in grass. They like cool, moist conditions when in active growth, but will tolerate a dry summer, and are best planted in light shade. They thrive in neutral to alkaline, humus-rich soils with plenty of leaf-mould, but note that they dislike manure. They can be naturalised in weak grass under deciduous trees or shrubs, and are lovely with hellebores and ferns.
Winter aconites, just 4” tall, are among the earliest bulbs to appear, bringing a splash of welcome golden-yellow under grey winter skies; they have charming green ruffs below their flowers. They will naturalise in grass under trees, in any well-drained, reasonably fertile, preferably limy soil, and do best in light shade The leaves must not be cut back after flowering, to allow the tubers to fatten up for next year. Once established, they will seed about lightly. Good with snowdrops and blue pulmonarias.
The familiar native bluebell is far more graceful and a more intense blue than the Spanish bluebell, and, unlike the Spaniard, is also deliciously scented. They prefer partial shade, and are particularly good under deciduous trees – they are far too thuggish for perennial borders, although they are good under roses. Plant with the bulbs 8” deep in any humus-rich, well-drained soil that does not dry out. As they interbreed with Spanish bluebells, it’s worth digging up the latter if you already have them. Future Forests’ native bluebells are grown under licence. Best on their own, in drifts under trees.
Lily-of-the-valley is a joy in May, with its ravishing scent and pretty stems, up to 25cm tall, of nodding, pure white bells. They are sold as ‘pips’, rhizomes with growing points, and should be planted so that the stem below the growing point is just clear of the soil. Lily-of-the-valley likes a consistently moist, humus-rich, clay or loam soil and will tolerate poorly drained soil. Plant in partial to full shade; it will not tolerate full sun or a dry soil. It’s particularly good under shrubs which are late into leaf, or by themselves against a north wall bounded by a path. Choose the site carefully, as it will spread vigorously in conditions that suit it, forming a dense (and useful) ground cover. If the weather is cold and wet when the pips arrive, it is better to plant them singly in pots under cover, and then plant out the whole pot as the weather improves.