What is health pruning?
Health pruning is the continuous, yearly pruning of shrubs and trees to ensure proper growth habits. It is not shearing a shrub or loping off various tree limbs.
Pruning is an art. When you prune any plant, you are changing its growth habits, shape, and appearance. Once you make a cut, it's final. Many plant species require different pruning methods. Some can be pruned to a lower bud or leaf (roses), while others require pruning to the next branch split (yews). Repairing bad prune cuts can take years for a shrub or tree to recover from. Most end up dying within 1 - 3 years for shrubs and 5 - 10 years for trees. This may seem like a long period of time but when you are dealing with a species that may live hundreds of years, it's not very long at all.
Most plant and tree species try to recover from bad pruning by sending off sucker growth, multiple stem growth from the lower trunk. You may think that this is a positive sign of new growth development but in reality, it is a sign that the plant or tree is dying.
Air circulation is a big factor in the health of your shrub or tree. To many branches crowding the center will decrease air circulation and cause the center to die. This is most prominent in evergreens (i.e.: cedars, junipers, spruce, pine, etc.). Once the center is dead, the entire plant will soon die as well. Deciduous shrubs will show this display of center-crowding branches when they have been poorly pruned or sheared.
Rules to remember when pruning:
1. Never prune more than 1/3 of a shrub or tree
2. Always make sure the species your planting will be sustainable in its new home (i.e.: Does it spread or have prolific roots? How big does it grow? Is there enough room? Will its growth interfere with your home or hydro/phone lines?)
3. Try to avoid removing tree limbs that are larger than your wrist.
4. Only remove dead, dying, diseased, rubbing or touching branches