On the cutting edge...
Many
of us aren't sure which plants in our landscapes should be pruned or why
to prune them. Just because the neighbor down the street has shrubs sheared
into globes, squares or cylinders is not reason enough.
The most common reason to reach for the pruners is because a tree or shrub is growing out of bounds, spreading over sidewalks or patios, or interfering with other plants. If reducing the size of your plants is the only reason you are pruning, it is likely that the plant has not been given enough space in the first place. A plant that naturally grows to five feet tall and wide will never fit into the two-foot space between the sidewalk and the fence. It will need constant pruning to maintain it. Constant pruning leads to health issues for the plant and green waste that must be disposed of. A better strategy is to select a plant that will be able to grow to its full mature size in the space you have available.
A plant's natural form is usually the most desirable. Natural growing plants lend an appealing, informal look to the landscape. A properly pruned shrub or tree is a work of art and beauty and does not look as if it has been pruned. Pruning cuts should not be visible but located inside the plant where they will be covered by remaining foliage. Remember, each time you make a pruning cut, you are opening up a wound on your plant that will provide easy access for pests and diseases. Pruned plants require more water and fertilizer because you have removed the leaves that would normally produce energy for the plant.
The first step in pruning a shrub is to remove all dead, diseased or injured branches. Remove branches that cross or touch each other and those that look out of place. If the shrub is still too dense or large, remove some of the oldest branches. This can be done by pruning techniques called select target, heading back, and thinning. Do NOT use hedge shears. Shaping shrubs like Texas 'sage' and desert cassia into round balls destroys their shape and blooming potential. More importantly, shearing causes the lower part of the shrub to become bare and twiggy. Eventually only the top of the plant is crowned with leaves.
To provide a more natural form, branches should be cut back to varying heights. This random heading back of branches will encourage new growth throughout the shrub. Pruning cuts also tend to be concealed using this method of pruning. Your plants will look great without ever being able to tell they've had a "haircut".
Winter is the best time to prune most deciduous trees and summer-blooming shrubs. When plants are dormant, removing twigs, stems and branches can be done with the least shock to the plant. Also, when done correctly, pruning can promote healthy spring growth. Desert trees and most spring-flowering shrubs should be pruned in the May in the low desert. They heal faster at this time of year. Never use pruning sealants (except on roses). These products can actually seal in fungus and bacteria where they can easily impact the health of your plants.
Never, never top a tree. Topping creates hazards because new sprouts are weakly attached and can easily break in the wind. The wound(s) created by topping will never heal and will continue to decay. Topping can lead to sunburn on newly exposed branches. Topping stresses trees. Topped, disfigured trees can reduce property values. It is always better to remove a tree that has been topped and start over with a new tree.
Finally, if you're in doubt about whether or not to prune a tree or shrub, then you probably shouldn't. Use the time you would have spent on unnecessary pruning and have some fun visiting local botanical gardens for new ideas for your landscape.
Here are a few tips to follow as you prune.
1. Always begin with a plan and stop when you have accomplished your goal.
2. Never prune a plant you love when you are angry.
3. Begin with your fastest-growing, toughest plants. This way your enthusiasm may have worn off a bit before you get to your expensive or slow-growing plants.
4. Don't clean up the clippings from beneath the plant until you are done. This way it will remind you how much foliage you have removed.
5. Stop periodically to assess what you have done and what is left to do.
6. Ask someone to interrupt every half hour to see if you are finished yet.
7. Never remove more than 25% of your plant in any one year. Removing more can starve or stress your plant making it vulnerable to sunburn, pests and diseases.
