Lesson in Proper Tree Pruning
Good pruning can be defined as ěpruning that improves or maintains
a plantís long-term health, beauty and safety.î As with trees,
shrub pruning is rarely done for the sake of the shrub itself.
Pruning is done to please the
landscape owner who is finding fault with the existing design.The
tree company is free to manipulate trees by pruning, as long
as the health and beauty (long term) of the tree is not degraded
by doing so.
Three kinds of cuts:
It is important to know the three kinds of pruning cuts, their
effect on the plant health and their aesthetic results. Over
the course of years the terminology for these cuts has changed,
unfortunately, several times causing confusion. I still prefer
the terms I was taught, and will use them here.
The first kind of cut is a "non-selective heading cut," used
by most gardeners. This cut shortens the length of a branch
by cutting it back to no place in particular, or internodally.
Non-selective heading cuts are the hardest on plant health
and aesthetics. This type of cut can cause dieback and the
formation of unwanted stubs. And, depending on the species,
it could stimulate the growth of water sprouts. Water sprouts
are the rapid growing, unattractive, and numerous new shoots
that are the common result of injury to plants, usually as
a direct result of mal-pruning. Once stimulated into existence,
water sprout cannot be stopped by removing them. This problem
occurs after 90% of licensed and unlicensed contractors cut
your trees. The prevention of water sprout formations should
be a primary concern for tree care specialist, which I am
sorry to say are in very short supply in Santa Barbara county,
as water sprouts can ruin the aesthetics of plants, and lock
the plant owner into a costly maintenance battle against their
trees; a battle that cannot be won.
The second type of cut is the "selective heading cut."
It is the right way to shorten a branch by cutting it back
to a lateral of goodly size. This cut has also been called
a "reduction cut" or a "drop crotch cut"
on trees. If the remaining lateral is large enough, there
will be no dieback and no water sprout response. The selective
heading cut is also a general stress on a plant, though not
as hard on health as a non-selective heading cut. Shrubs,
far more than trees, can withstand overall size reduction
pruning, although their response varies greatly according
to their species.
The third kind of cut, the "thinning cut," removes
a smaller lateral branch by cutting it off where it joins
the larger, parent stem. This cut is the easiest on the health
of the tree. Thinning is used to remove lower limbs of trees
and shrubs (skirting, limbing-up). Numerous small thinning
cuts can also be used throughout trees, making them less dense
but not smaller in size. Thinning is often used to highlight
the good internal branch structure of those trees and that
have it. This does not mean strip off all the small branches
inside the tree to show the limb structure. The thinning is
usually needed in the outer 30% of the limb leaving at least
75% of the inner limb in place. Removing these limbs is a
common practice and is called "stripping." 75% of
the foliage on each limb is removed with absolutely no attention
payed to the most important area ‚ the outer 30%. Under normal
conditions no more than 25% of the entire tree should be removed.
At this percentage even wind and rain should not be a problem.
If someone tells your this is not true, you need to consider
the credibility of who your are consulting.
For more information please contact your local tree care specialist.