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A Wood That Keeps a Diary

Every tree in a British wood is quietly writing an annual report. Each growing season leaves a new layer of wood just under the bark, and a cross-section of trunk or branch reads like a ledger of everything that happened while that layer formed. A wide, pale ring usually means a generous year — plenty of light, mild temperatures and steady moisture. A narrow, dark one points to drought, a late frost, insect attack or the cramped conditions of a suppressed tree. For most of our native broadleaves, including oak, ash and beech, the rule of thumb is one ring per year, though it is a guide rather than a guarantee.

That single fact is what makes tree rings so appealing to anyone who walks the same patch of woodland each week. You do not need laboratory equipment. You need a fallen branch, a bit of patience and a notebook.

What to Gather, and What to Leave Alone

Ethics come first. Never cut a standing tree, and never take timber from a site with protections attached — ancient woodland, Sites of Special Scientific Interest and many reserves are strictly off-limits for removal of any kind. What you want is material that has already come down: a storm-felled limb, a hazel stool cut during traditional coppicing, or a disc from a tree felled under a licence. Ask the landowner or the woodland trust that manages the site, and explain what you are doing. In my experience, people are curious rather than obstructive.

For a reading kit, keep it small and cheap:

• A pruning saw or folding saw for cutting a 5–10 cm thick disc from dead or already-fallen wood
• Sandpaper in three grades — around 80, 120 and 240 grit
• A hand lens of 10x magnification
• A soft pencil, a ruler marked in millimetres, and a notebook that tolerates damp
• A small tin of raw linseed oil and a rag, for finishing

Reading a Cross-Section

Sanding is where the magic happens. Work through the grits, always along the grain, until the end surface feels like a polished tabletop. Wipe away the dust and the rings appear, often with a clarity that surprises people who have only seen them in diagrams.

Find the pith at the centre and count outwards. Every tenth ring, make a small pencil tick on the bark edge of the disc — this gives you decades rather than an unmanageable tally. In ring-porous species such as oak and ash, the earlywood is pierced with tiny visible vessels, like pinpricks, while the latewood is dense and dark. The proportion of dark latewood is itself a record: a high proportion often signals a stressful year.

Watch for the oddities too. A frost ring looks like a thin band of damaged, distorted cells. Reaction wood — compression wood in conifers, tension wood in broadleaves — shows as uneven ring widths on one side, which usually tells you the tree was leaning, perhaps after a neighbouring tree came down.

Weather, Damage and the Years Behind Us

Once you have a clean sequence, you can start matching rings to memory. The drought summers of 1976, 1995 and 2018 typically leave narrow rings in lowland oaks. The Great Storm of October 1987 shows up not as a ring but as a scar or a sudden release in growth in the trees that survived around a gap. Earlier, the long, cool, wet years of the 1960s often produce broader, paler bands.

Elsewhere on the disc you might find insect galleries, a pocket of rot, or a band of charcoal-blackened tissue where fire once crept through the leaf litter. In woods with a history of charcoal burning, the ground itself holds the clues; the trees simply confirm the timing.

Keeping a Ring Journal

This is where tree rings pair beautifully with nature journaling. Lay the sanded disc on a sheet of thin paper and take a rubbing with a soft pencil or graphite stick — the ring pattern transfers in a few seconds and goes straight into your notebook. Record the species, the grid reference, the date you collected it and the diameter of the disc in centimetres. Then note a few ring widths in millimetres, measured from the pith, and jot down anything you noticed on the day: the weather, the birdsong, the state of the understory.

Do this at three or four points in the same wood and you can cross-date by eye. A narrow ring appearing at the same distance from the bark on two separate discs is almost certainly the same bad year — and that is precisely the method professional dendrochronologists use, just with more arithmetic and a lot more samples.

Crafts That Grow from the Grain

Sanded discs make honest, useful objects. Cut them 1–2 cm thick, dry them slowly indoors for a few weeks to avoid splitting, then sand and finish with a coat of raw linseed oil rubbed well in, followed by beeswax if you want a satin sheen. They become coasters, pendants, buttons, or the base for a hand-drawn year chart in your journal.

Larger pieces can be made into simple hanging panels with a drilled hole and a length of jute twine. Offcuts and shavings should go back where they came from — a small pile of deadwood at the edge of a ride provides habitat for beetles, fungi and solitary bees. Nothing from a healthy wood should leave it entirely.

The real craft, though, is attention. A disc of oak the size of your palm holds eighty or ninety years of British weather, and once you can read it, every fallen branch on the path becomes worth a second look.