Why bulbs and woodland plants suit the ground beneath deciduous trees

Beneath an oak, ash, lime or old apple tree, the gardening year arrives in two distinct halves. From February until the canopy unfurls in late May, light pours onto that patch of soil and the ground stays reliably damp. Then, almost overnight, the tree leafs up, the shade deepens and the same spot becomes dry, root-ridden and hostile to most things you might try to grow. Anyone who has attempted a lawn or a bedding scheme under a mature tree knows the result: thin grass, sulking annuals, and a great deal of bare earth.

Spring bulbs and woodland perennials solve this problem elegantly. They evolved on the floor of deciduous woodland, where the strategy is simple: grow hard while the light lasts, flower, set seed, then retreat underground before the tree takes over. Plant them beneath your trees and you work with that rhythm rather than against it. There is one more advantage. Deep-rooted trees draw moisture from below and leave the surface soil rich in leaf litter and humus, which is precisely the crumbly, woodsy texture these plants adore.

Snowdrops: the earliest reward

The common snowdrop, Galanthus nivalis, is the plant most gardeners think of first, and rightly so. It will happily naturalise under deciduous trees, spreading year on year into generous drifts if the soil stays moisture-retentive but never waterlogged. Single snowdrops open their honey-scented flowers from January onwards, and on a mild day you will find honeybees working them when little else is in bloom.

The secret with snowdrops is timing. Dry bulbs bought in autumn are a gamble; they dislike drying out and often take two or three years to settle. Far better to plant them ‘in the green’ in late February or March, straight after flowering while the leaves are still fresh. Lift a clump, tease the bulbs apart and replant immediately at the same depth, roughly 8–10cm deep and 10cm apart, then water well. Mark the spot with a discreet label, because by June there will be no trace of them and a careless hoe is the quickest way to lose a colony.

Wood anemones: the classic woodland carpet

Anemone nemorosa is the definitive woodland plant, and an indicator of ancient woodland in the British countryside. In the wild it grows in enormous sheets, but in a garden it spreads politely rather than aggressively, creeping by rhizome perhaps 30cm a year. The starry white flowers appear in March and April, sometimes washed with pink or lilac, and they close in dull weather and at dusk — an old country sign that rain is coming.

Plant rhizomes 5cm deep and 10–15cm apart in autumn, laying them horizontally. They want a humus-rich soil that never dries out completely in spring, so add plenty of leaf mould or garden compost before planting. Avoid the driest spot under a shallow-rooted tree such as a birch or a beech, which will starve them of moisture at just the wrong moment. Once settled, they will seed about gently and give you the carpet effect you were hoping for.

Cyclamen: colour where nothing else dares

Cyclamen coum is the winter and early spring species, flowering from January to March in magenta, deep pink or white, above neat rounded leaves often marbled with silver. It is tougher than its delicate looks suggest and tolerates quite deep shade, so it is ideal for the dry side of a tree. Plant the tubers shallowly, no more than 2–3cm deep, in late summer or early autumn, with the smooth side downwards and the slightly dimpled top just at soil level. Bury them too deeply and they will simply rot.

Cyclamen appreciate a summer rest, which a deciduous tree provides perfectly: dry shade from June onwards suits them down to the ground. They self-seed freely once happy, and the seedlings appear in the most charming places — between tree roots, at the edge of a path, tucked against a stone. Do not tidy away the seed pods. For autumn interest in the same position, add the ivy-leaved cyclamen, Cyclamen hederifolium, which flowers in September and October under the very same canopy.

Good companions for the same ground

• Winter aconite (Eranthis hyemalis): buttercup-yellow cups in February, best planted as fresh tubers or in the green.
• Bluebells: the native Hyacinthoides non-scripta for a properly British spring, though it needs a light hand and room to spread.
• Glory of the snow and squills: small, cheap and utterly reliable, forming pools of blue in March.
• Early daffodils: short varieties such as ‘February Gold’ or Narcissus pseudonarcissus, which finish before the canopy closes.
• Snake’s head fritillary: for a damp corner under willow or alder, where its chequered bells look superb in rough grass.
• Hellebores: not bulbs but perfect bedfellows, flowering through the same bare-branch window.

Planting well and keeping them coming back

Preparation makes the difference between a few flowers and a proper colony. Clear ivy and coarse weeds, then fork over the top 15cm without disturbing the tree’s larger roots. Spread a 5cm layer of leaf mould or well-rotted compost and fork it in lightly. As a rule of thumb, plant bulbs at roughly three times their own depth, and space the smaller woodland species 8–10cm apart.

After planting, water once and mulch with more leaf mould, keeping it clear of stems. The single most important rule is to leave the foliage alone until it has yellowed and collapsed on its own, usually six weeks after flowering. That green tissue is feeding next year’s bulb. If the area is within a lawn, resist the urge to mow until June, or simply plant in a defined patch and let the grass grow long around it. Squirrels will sometimes dig up freshly planted crocus and snowdrop bulbs; a sheet of chicken wire laid just below the surface, or a scattering of prickly holly leaves, usually sees them off.

Finally, be patient with the trees themselves. A young oak will not cast serious shade for another twenty years, so plant for the garden you will have, not the one you have now. Snowdrops, anemones and cyclamen all divide and multiply generously with age, and there are few lovelier sights in a British garden than a drift of white and pink running back into the shade of bare branches on a bright March morning.