Gilbert Ranch

Pruning

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. Did you know that over 40% of materials sent to the landfill
consists of green waste? 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.

If you want to learn more about the correct pruning of desert plants, I
highly recommend Pruning, Planting & Care, by Eric A. Johnson. It is a
guide to pruning plants of the Arid West, with lots of color photography
and step by step instructions. It can be purchased at many local bookstores
or even on-line. ISBN 0-9638236-5-1

Cathy Rymer
Greenfield Lakes