Every branch needs a place to be. It is the reason for pruning otherwise healthy trees. If a branch is close to or already touching or crossing another, it will get worse as they grow. Removing or shortening one or both will create needed space. It also allows air circulation and sunlight, both necessary for leaf growth, to enter the inside of the tree. Dead branches are a potential place for disease to grow and are best removed. Already diseased branches must be removed if the problem is not to spread to the rest of the tree and possibly neighbouring ones, as diseases can spread by insects and wind.

Trees are so often planted in the wrong places, with little or no thought to mature size, that the answer seems to be to prune it to keep it small. This is a short-term, frustrating solution that ultimately doesn't work. Trees are genetically programmed to reach a certain adult size. Removing a large proportion of the branches means that the tree has fewer places to put needles or leaves that are necessary for photosynthesis. The roots absorb water and nutrients from the soil, but there aren't enough leaves or needles to absorb sunlight, which the plant needs for survival. Often, it is better to replace a tree that is outgrowing its space and replace it with a more appropriate tree.

Spruce trees are a perfect example of this. Those cute little trees that look so perfect in a flower bed will grow to twelve feet wide and thirty-five feet high! The needles on the inside of the tree die every fall. This is a natural occurrence and not an indication of poor health. Each spring, new needles grow on the tips of the branches. If these are removed, as the oldest needles die, the tree will resemble a telephone pole with green needles only on the ends. If a branch doesn't have enough needles, it will begin to die.

There are a few easy rules for pruning. A branch to be removed completely, or back to a much larger branch, is cut at the outside of the collar, a wrinkled area where it joins the trunk. A branch that is to be shortened is cut just beyond a smaller branch, which will be at the end, and at the angle of that branch. A few years after purchasing a young tree, it is a good idea to evaluate the tree's structure and create a 'backbone' for future growth. Look at the tree from several directions, before it leafs out in the spring, and prune to allow each branch future branch space, and shorten to practical size and natural shape of that tree. A tree should never look 'pruned' after you are finished, simply tidier and nicely shaped. If this is repeated periodically, the tree will rarely need drastic pruning.

Most deciduous trees and shrubs are pruned in the spring before they leaf out. Exceptions are birch and maple, which are pruned in July after rapid spring growth finishes. They will drip copious amounts of sap if pruned in the spring - remember where maple syrup comes from? Birches do the same thing, and syrup can be made from them, too. Shrubs that flower in the spring on buds that are formed in the fall, such as Nanking cherry, lilac, some roses, and white flowering spireas, are pruned after they bloom. Shrubs that flower in the summer, such as pink flowering spireas, most shrub roses, and potentilla, are pruned when green buds appear. Any winter tip kill is removed and branches trimmed to an appropriate size and shape. Pine trees and shrubs have new growth called candles that are snapped in half in June to make a somewhat bushier appearance and compact shape. Spruce trees are rarely pruned, although many people remove a few of the lower branches when most of the needles have died. Junipers and cedars may be sheared a little, but remember the rule about removing too many new needles!

Pruning shears are used for small cuts and should be sharpened frequently enough to make clean cuts. Somewhat larger branches may be removed with lopping shears, or a saw. If a large branch is to be removed completely, make an upwards cut a foot or so beyond the trunk, halfway through the branch.

Then cut downwards beyond that cut. The branch will break off when it is being cut downwards, and default to the upwards cut, but not damage the trunk. The final cut can be made without ripping bark off the tree as it falls.

Keep pruning tools clean and sharp. If the tree is diseased, clean after every cut by dipping into a solution of one part bleach to ten parts water. Don't try to prune beyond your capabilities! If you are not sure you can handle it, call a certified arborist, who has the proper knowledge, experience and tools, to do the job. Pruning is quite satisfying and interesting. Creating a shape for a tree that is pleasing and natural can be a work of art.