Now is a great time to prune because you can see branch structure and you don't have to worry about trampling the garden. But these neighbours of mine do this to their front yard tree every year - does anyone think this looks good? Or is good for the tree?
What NOT to do:
- don't top the tree (besides looking terrible, it leads to weak growth and probably decay)
- don't leave too much or too little of the pruned branch (there shouldn't be a stub left but don't cut into the collar where the branch joins the tree)
- don't cut off more than about 15% of live branches from a tree in one year
- don't go crazy: take a step back once in a while to look at what you're doing!!
If you're really unsure about pruning your trees, get someone with experience to help you, or if it's too big to handle yourself, call a certified arborist to do it properly.
As for shrubs, they are generally a little more forgiving. Generally I alternate every year between heading back (reducing the length of some branches by cutting them back to an outward facing bud or to a good lateral branch), and thinning (removing branches by cutting them off at the ground).
If your trees or shrubs are totally out of control, take a few years to get them back into shape. Or some shrubs can withstand being cut back to the ground occasionally: lilacs, caragana, honeysuckle, and ninebarks fall in this category.