Pruning cuts should be made correctly to maintain tree health. Thinning cuts, which shorten large limbs back to side branches large enough to resume growth, are the best choice. Stub cuts, where limbs are cut without regard to buds or branches, and heading cuts, which trim limbs back too far, should be avoided as they can damage the tree. No more than 30% of a mature tree's foliage should be removed during pruning in any given year.

1. No more than 30 percent of a mature tree’s
foliage should be removed in any one year.
STUB
CUT
THINNING
CUT
HEADING
CUT
Graphics / Illustration: Tom Laird, College of Agricultural Sciences. © Penn State 2000
Monitoring Tree Pruners: Know Your Cuts
Additional graphics and information available on the Internet at aginfo.psu.edu/psp
Penn State Pointers
For Spring/Fall Time Frame
THINNING CUT
This cut is used to shorten a
large limb back to a side branch
large enough to resume growth
of the pruned limb.
The use of thinning cuts is the
correct choice to maintain trees.
STUB CUT
The limb is cut indiscriminately
where no bud or side limb exists.
A stub cut is highly destructive to
the tree and should be used only
when removing the tree.
HEADING CUT
The result of trimming a limb back
to a bud or a very small branch
that can’t support the growth of
the pruned limb is called “heading.”
Heading shouldn’t be used unless
the tree is being removed.
These pruning cuts are
commonly used by
certified arborists.