Hurricane
Ike Landscape Recovery & Renovation:
Dr. Don C. Wilkerson, Professor & Extension Specialist
Texas AgriLife Extension
Department of Horticultural Sciences
Texas A&M University
College Station, Texas
 Like many that have experienced Hurricane Ike I was surprised at the devastating
effect the storm had on mature trees and shrubs across the island. What
foliage was not blown off appears to completely fried. Mature live
oaks, palms, oleanders, bougainvillea - few plants survived without some
type of serious damage. Unlike many plant problems, it has been relatively
easy to diagnose the origin of this condition. Hurricane force winds and
being submerged under saltwater for an extended period of time is unquestionably
the cause. The question now becomes - will these plant materials survive
or should they be removed?
In our opinion,
mature trees and other specimen plants stand and excellent chance of
recovering. Tender, herbaceous annuals and perennials will have a more
difficult time but may also survive. Ultimately this will be a judgment
call but it is important to understand the facts BEFORE determining
the fate of damaged landscape plant materials.
What were the
causes?
Lets first discuss the direct cause. Excessive salt levels (mostly sodium)
are largely responsible for the characteristic burning that has occurred.
Salts are notorious for causing the crispy burn usually observed on
leaf tips and margins. These salts can occur naturally in tap/well water,
from excessive fertilizer applications or in this case, from wide-spread
flooding. Add to this situation the moisture loss associated with hurricane
force winds and you now have an ideal scenario for widespread leave
burn (some times referred to as necrosis). In addition to foliar damage,
excessive salt levels can also cause severe root damage. Luckily, sandy
soils tend to drain well and hopefully much of the residual salt has
been or will soon be leached from root zone, thus reducing the potential
for injury.
What to expect…
Mature trees and other plant materials may take some time to put out
a new flush of growth. It would not be uncommon for some plants to take
up to 6-8 months before they begin to show signs of life. Use your thumbnail
to scratch back the outer layer of tissue on woody stems or branches.
Soft green wood indicates that the plant is still alive.
For those plants
that do survive, expect an increased incidence of short term problems
like die-back, cankers, borers, tip blight and other common insects
and diseases. Long term, expect more problems associated with heart
rot, broken limbs and structural integrity issues resulting from storm
damage.
What to do…
Patience is the key. The process of getting mature trees and other plant
materials back in to good condition may be long and difficult. The best
course of action is to limit plant stress. Monitor watering carefully.
Irrigate as needed but DO NOT OVER WATER. Root systems are already stressed
and excessive moisture promotes a variety of root diseases. Provide
TLC but don't love plants to death! DO NOT apply excessive levels of
fertilizer in an attempt to promote growth. Fertilizers are SALTS similar
to those that have caused the problem in the first place. Fertilizers
are not a medicine for sick plants and if applied improperly, can do
much more harm than good. Heavy pruning and excessive fertilizer applications
stimulate tender new growth which is more easily damaged by insects,
diseases and cold weather. Promoting new growth at this time of year
increases the potential for freeze/cold weather damage - something we
usually don't have to worry about but very much within the realm of possibility.
Carefully prune
damaged limbs, branches and fronds. Make sure that all pruning tools
are sharp and in good condition. Make flush cuts and do not leave stubs
which may decay and/or promote insects. Make clean cuts and do not strip
the bark back by pulling limbs/branches/fronds from the trunk. Consult
an arborist for larger branches and limbs. Proper pruning is critical
in reducing stress and limiting log term problems.
Galveston and surrounding
areas are known for stately live oaks, palms and a unique diversity
of plant materials. Understanding the effects hurricane Ike has had
on the landscape, as well as how best to care for damaged plants will
help get trees and shrubs on the road to recovery.
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