Autumn Jobs for a Healthy Woodland Garden

Make the Most of the Leaf Fall

There is something deeply satisfying about a woodland garden in October. The canopy turns to copper and gold, the air smells of damp earth and fungi, and every gust of wind sends another shower of leaves tumbling onto the lawn. It is also the moment when a little well-judged work pays you back many times over next spring. The weeks before the first hard frost are precious, and the jobs you do now will shape how your trees, bulbs and borders come through the winter.

Start with the leaves, because they are both the pleasure and the problem of the season. A thick, wet blanket of leaves left over the crown of a lawn will smother the grass beneath, encouraging moss and disease. On the other hand, those same leaves are free mulch, free soil conditioner and free habitat. The trick is to move them from where they cause harm to where they do good.

• Rake lawns and paths every few days rather than waiting for one big clear-up at the end of autumn.
• Leave a generous layer of leaves under mature trees, shrubs and hedges, where they will rot down and feed the soil.
• Sweep leaves clear of drains, gutters and doorways before the winter rains arrive.
• Keep leaves away from the crowns of alpines, small bulbs and newly planted perennials, which can rot beneath them.

Turn Rubbish Into Leaf Mould

Leaf mould is one of the finest soil improvers you can make, and it costs nothing but patience. Collect damp leaves into bin bags, punch a few holes for air, and tuck them behind a shed or hedge. Alternatively, build a simple wire cage in a quiet corner and fill it as the season progresses.

Not all leaves break down at the same speed. Oak, beech, hornbeam and sweet chestnut are rich in tannins and can take up to two years. Sycamore, lime, cherry, ash and horse chestnut rot down in a year or less, so it pays to keep the two groups in separate bags or bays. Shredding leaves with a mower before bagging them speeds things up considerably. By the following autumn you will have a dark, crumbly material to dig into borders, use as a mulch or mix into homemade potting compost.

If you have room for only one heap, keep it damp and turn it occasionally. A handful of soil or old leaf mould added at the start introduces the fungi and bacteria that do the real work.

Plant Bulbs While the Soil Is Still Warm

October and early November are ideal for planting spring bulbs, while the ground still holds some warmth and roots can establish before the cold sets in. In a woodland garden, the natural look is a drift rather than a row, so scatter a handful and plant them where they land.

• Snowdrops and winter aconites suit the damp shade beneath deciduous trees and will naturalise readily.
• Wood anemones and native bluebells prefer dappled shade and soil rich in leaf litter.
• Daffodils and narcissi cope with most conditions and will shrug off late frosts.
• Cyclamen hederifolium and coum are excellent for dry shade under mature trees.

Plant bulbs at roughly three times their own depth, point upwards, and water them in. Add a handful of gritty material to the base of the hole if your soil is heavy clay. Mark the area with small stakes or twigs so you do not accidentally dig them up later, and resist the urge to tidy the dying foliage in spring: the leaves feed the bulb for next year.

Protect Young Trees Before the Frosts

Young trees are the most vulnerable plants in the garden at this time of year. Their bark is thin and tender, their roots are still shallow, and they have not yet developed the resilience of an established specimen.

The first priority is a sturdy stake and tie. Check that the tree is not rubbing against its support and that ties are firm but not tight enough to strangle the trunk as it thickens. Where rabbits, deer or squirrels are active, wrap the lower trunk in a spiral guard or a cylinder of mesh buried a few inches into the soil. Mulch around the base with a ring of well-rotted compost or leaf mould, keeping it clear of the trunk itself to avoid rot.

Water newly planted trees thoroughly before the ground freezes, especially evergreens, which continue to lose moisture through their leaves all winter. A deep soak once a week during dry spells in autumn is far better than frequent light sprinklings.

Bare-root trees can still be planted in November while the soil is workable, but hold off if there is frost in the ground or the forecast is for a hard freeze. Container-grown trees can go in at almost any time, provided you keep them watered.

Carry Out a Little Pruning and Tidy-up

Autumn is not the season for major pruning, but a light tidy is worthwhile. Remove dead, damaged or crossing branches from mature trees, and clear any broken limbs after storms. Take out the spent fruiting canes of summer raspberries and cut back tatty perennials, leaving seedheads on teasels, sedges and ornamental grasses for the birds and for winter structure.

Diseased material should go into the bin, not the compost heap, particularly anything showing signs of coral spot, canker or honey fungus. Clean your tools between cuts with a cloth dipped in methylated spirits, and sharpen your secateurs before you put them away for winter. If you have a mature apple or pear tree, now is the time to remove any rotten fruit from the ground and to scrape away loose bark where pests may be sheltering.

Look After the Soil and Wildlife

A woodland garden is an ecosystem, and the more you can work with it, the less work you will do in the long run. Avoid digging over the soil beneath trees: their roots are close to the surface and easily damaged. Instead, top-dress with leaf mould or compost and let the worms do the work.

Leave a pile of logs, a stack of sticks or a small patch of nettles and brambles in a corner. Hedgehogs, frogs, beetles and overwintering butterflies all need somewhere to shelter. A shallow dish of water, refreshed regularly, will see birds and insects through the drier spells.

Finally, take a moment to enjoy the season. A woodland garden rewards patience more than frantic activity, and the quiet weeks ahead are as much a part of its health as any job on this list. Do the essentials now, leave the rest for spring, and let the trees get on with what they do best.