Everybody can name a tree in June, and almost nobody in January
Buds
The most reliable winter feature. Opposite or alternate, and then colour and shape. Ash is unmistakable once you have seen it once.
Bark
Useful for about a dozen species and misleading for the rest. Young bark and old bark on the same species look nothing alike.
Overall shape
Visible at a distance and the fastest way to narrow it down. Oak, ash, and beech are distinguishable from a moving car.
