WANT a rough idea of how to age a tree? Measure around the tree with a tape measure 1.5 metres from the ground. Divide this number (in centimetres) by 2.5 and you have a rough estimate of the tree's age in years. I say "rough" as trees grow at different rates depending on their living conditions.

I mention this because a reader asks why do we see rings when a tree is felled, and not simply one overall colour? What we are seeing is growth rings. The light layer is the wood put on in spring and summer whilst the dark layer is that of the wood put on in autumn and winter.

The number of concentric rings will give you the age of the tree up to when it was felled. There are 2.5 cms to an inch, or 30cms to 1ft if you have a pre-decimal tape measure.

Useful tip for the outdoor person who uses a walking stick. I put a band of insulation tape at 6in, 1ft, 18in and so on up to 3ft just in case I want measurements of plant heights.

Suffering from a cold? Take lots of fluids including warm drinks and eat nutritious foods. Try a sliced tomato and raw garlic sandwich. Try thyme tea. Headache? Rub a cabbage leaf where it hurts. Not in public, it looks silly. But it does work.

Looking around in the great outdoors we often find red campion in flower in winter. It, too, has its medicinal uses, its rather corrosive juice used against warts and corns. An ointment made from it was made for snake bites.

One cannot but wonder at those who tried and tested herbs and other plants to discover whether they were safe medicinally for both external and internal uses. It conjures up pictures of people clutching their throats and falling about all over the place.

For example watercress was used as a wart cure, a remedy against colds, coughs and chest complaints, kidney ailments, heart trouble, rheumatism, cuts, swellings and sore eyes. Its use as a blood purifier and tonic is well known and in the Highlands of Scotland it was used to correct barrenness in women.

It seems a good plant to eat with salads as it is today.

Trevor Beer will answer your natural history & countryside questions.

Drop him a line at 38 Park Avenue, Barnstaple, EX31 2ES