Aging trees

[Roger B]

How can I tell how old a tree is by measuring its girth?

[richard1983]

If you measure its circumference near the base, then every inch (or 2.5cm) represents one year. Bear in mind that this is only a rough guesstimate at best!

[incitatus]

Yes. It's complicated by situation, as in dry years or places with poor soil the growth rate is much less. The best method for tree aging is counting rings on a core sample, but you can get another guesstimate on deciduous trees by counting major forks. Rule of thumb is one large branch every five years. Beware of pruning, though.