Q.Elderberry pruning
I want to prune my elderberry bush. It is about 4 years old. How can I tell the 3 year canes from 2 year & 1 year canes?

Generally, the stalk that everything originates from will be the oldest, and closer to three year growth. The secondary branching is the second year's growth, and the new growth at the tips are fresh first year growth. This article will give you more instruction on pruning these: https://www.gardeningknowhow.com/edible/fruits/elderberry/pruning-an-elderberry.htm