[Arid_gardener] Re: Pruning Dead Wood

[Olin Miller]

Advice from several land grant university cooperative extension sites:

Iowa State:

http://www.extension.iastate.edu/Publications/PM1133.pdf
" ...Pruning dead branches also requires care to minimize possibility of
injury and to promote fast healing. Do not cut into the callus ring that
forms around the base of dead branches. Cut as close as possible to the
callus ring, but do not wound the callus material (figure 4). Damaging the
callus ring will slow the healing process and promote internal decay. ..."

http://extension.usu.edu/files/natrpubs/ff004.pdf
 " ...Pruning Dead Branches - Shortly after a branch dies a swollen ring of
woundwood starts to form around its base. A branch protection zone also
forms in the wood at the branch base. This zone contains chemicals that help
the tree resist microbial attack. Cut off dead branches just outside the
live woundwood without leaving a stub (see broadleaved diagram on page 2).
Promptly remove large dead branches since they pose significant hazards.
..."

North Carolina State University

http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/trees-new/text/pruning.html
" ...A tree branch has a branch bark ridge, which denotes where the upper
side of the branch meets the tree trunk (Figure 3). The bark collar is the
swelling located at the base of a branch where the lower side of the branch
joins the trunk. The natural decay of a dead branch usually does not spread
beyond the collar. When pruning a dead branch, do not create a new wound by
cutting into the collar of live wood that forms around the dead branch. ..."

Big Brother

http://www.na.fs.fed.us/spfo/pubs/howtos/ht_prune/cuts.htm
http://www.pueblo.gsa.gov/cic_text/housing/prune/prune.htm
2.  ...Pruning dead branches (Fig. 6)
"Prune dead branches in much the same way as live branches. Making the
correct cut is usually easy because the branch collar and the branch bark
ridge can be distinguished from the dead branch because they continue to
grow (Fig. 6A). Make the pruning cut just outside of the ring of woundwood
tissue that has formed, being careful not to cause unnecessary injury (Fig.
6C). Large dead branches should be supported with one hand or cut with the
three-step method, just as live branches. ..."

University of Florida

http://hort.ifas.ufl.edu/woody/cleaning.html
"Dead or touching branches: Remove detached, dead, broken, and diseased
branches especially those more than one inch in diameter. Never remove the
swollen expanding collar growing around the base of dead branches. Cut just
to the outside of this collar. If two branches touch, remove or shorten one
of them so they no longer touch."

http://hort.ifas.ufl.edu/woody/deadbranchremoval.html
" ... Cut all dead branch tissue from the tree, but do not injure the
collar. If the branch is small or severely decayed, you might be able to
simply break the dead branch from the tree. This often allows you to remove
more of the dead tissue inside the edge of the collar. Do not break the dead
branch if this could injure the collar. ..."

Cornell University

http://counties.cce.cornell.edu/suffolk/grownet/tree-shrub-maintenance/pruntree.html
" ... Correct removal of the dead branch is accomplished by cutting it from
point C1 to point C2. Notice, that the cut is made so no injury occurs to
the newly forming wound wood, but at the same time a stub is not left. ..."



ColoradoState University

http://csfs.colostate.edu/library/pdfs/pruning/pruning_mature_shade_trees.pdf
" ... Remove the dead branches with correct thinning cut techniques using
the 3-step pruning technique. For details refer to fact sheet 7.821, Pruning
Cuts. Do not cut into the branch collar because decay can readily spread
into the trunk. If the bark of the branch collar has begun to grow out along
the dead limb, cut just beyond the branch collar, being cautious not to nick
the collar. Never flush cut the dead branch. ..."