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Hi, I am Charlie Pepper,
at the Magnolia Plantation in
Natchitoches, Louisiana.
This video provides guidance on the
concepts and techniques of replacing individual
trees at historic properties.
Trees in historic landscapes are
often important cultural resources that
contribute to the significance and integrity
of a property. Preserving important trees
in historic landscapes can present
difficult and complex challenges.
Many of the inherent characteristics
of trees, such as growth and the associated
change in size, can seem incompatible
with traditional preservation objectives
of sustaining the original form
of historic features.
However, the fact that trees grow, age,
and change in character does not diminish
the fact that they are often important parts
of the historic record that
should be preserved.
Even with the best of care,
trees in historic landscapes will
eventually deteriorate.
Common reasons for tree removal include:
structural instability,
which can pose serious safety hazards;
adverse impacts to adjacent resources,
such as tree roots damaging the foundation
of a historic structure; or, an irreversible
decline in health due to age, disease or
pest infestation.
Removing an existing tree can be hazardous.
It should only be accomplished
by a certified arborist.
When preparing to replace a tree
at a historic property there are
several steps that should be considered.
These include: documenting existing conditions,
selecting the replacement tree, and
using appropriate field techniques
to minimize site disturbance.
Documenting information about the removal
and replacement of trees in historic
landscapes provides valuable information
for future reference.
Prior to removing a deteriorated tree
or planting a new one, record information
about the condition of the existing tree
and the site where it is growing.
These records are valuable for tracking
preservation treatments and trends
in resource condition over time.
They will be especially important
when replanting is needed again
in the future.
When selecting a replacement,
it is important to retain the
qualities of the original tree.
If possible, an in-kind replacement,
propagated from the existing tree,
should be used.
Alternatively, a tree of the same species
or one with similar qualities such
as size, canopy shape, and foliage
character, can be an acceptable substitute.
Several considerations before determining
an appropriate replanting method include:
Are recommendations from cultural
resource specialists such as archeologists
or landscape architects needed?
And are there fragile resources
(above and below ground) near the planting
site that will limit equipment access?
Standard horticultural tree planting methods
involve using heavy equipment to prepare
a hole that is 5 times the
width of the rootball.
This approach, while good for the
tree, can cause major disturbance
and significant damage to the site.
In resource sensitive areas with
rich archeological features such as
the slave quarters at Magnolia Plantation,
standard horticultural planting methods
can be modified to reduce damage
to cultural resources.
We are going to be demonstrating two
methods that minimize potential damage
to historic features.
The first demonstration will be
Mound Planting - a technique that
is effective for replacing trees
in locations where it is necessary
to minimize ground disturbance.
This method mounds soil around a
rootball that is placed in a slight
depression in the existing grade
and does not require digging a deep
planting hole.
The mounding of soil can alter site
grading and change the visual
character of the landscape.
Because of this, it is best to
use small replacement trees that
will require minimal mounding to cover
the rootball.
Using a pointed shovel or garden rake,
remove the existing soil and vegetation
to a depth of 2 or 3 inches in a
circular area that is 5 times the
diameter of the roots.
Remove all nursery packing material
from the plant and accumulated material
from the top of the rootball.
In addition, using a knife or razor,
vertically score the roots to encourage
lateral growth.
Place the tree so the rootball rests
solidly on the ground and the trunk is upright.
Mound around the tree using soil from the
original location or fill that matches the
original soil as closely as possible.
Taper the mounded soil into the
surrounding grade and apply 1 or 2
inches of organic mulch, such as wood
chips or pine straw, to prevent erosion.
Water well.
Because the planting is above grade,
the soil will be prone to drying.
Regularly monitor soil moisture and
irrigate as needed. Once the tree
becomes established, which will take
about one or two years, roots will
extend beyond the mound and will be
less susceptible to drying.
The next method is planting into
a decayed stump.
As with the mound planting,
using a small replacement tree will
require less digging and reduce the
potential impact to adjacent
cultural resources.
This method is ideal for replacing
trees in the exact location of the
original to preserve the historically
authentic character of the site.
Start by assessing the extent of decay
in an existing stump.
Replanting within a stump will only
be successful if decomposition
is well advanced.
Ideally the stump should have minimal
or no solid wood remaining.
The rootball needs to be small enough
to easily fit into the decomposed area
of the stump with at least 6 to 8 inches
of additional space on each side for
backfilling with soil.
Using hand tools such as a
pointed shovel and axe, break up and remove
the decayed wood remaining within the stump.
Create adequate space for planting
and backfilling with soil.
Once it has been properly prepared,
elevate the top of the rootball
3 to 4 inches above the surrounding grade.
As the remaining stump decomposes
over the next few years, the rootball
will settle further into the hole.
Backfill the hole with soil that
matches the original material as
closely as possible.
Use two to three inches of
mulch over the rootball
Be sure to keep mulch
atleast two inches away from
the tree trunk to prevent damage
Water the tree well to ensure good
initial establishment.
Maintenance of a newly planted tree
is critical to ensure its survival.
Each week, for the first year after
planting, apply approximately 1” of
water through irrigation and/or rainfall.
Allow the tree to aquire natural
accuring nutrients from the soil
Do not fertilize unless
there is a visible nutrient
deficiency, such as yellowing of
the foliage which can be confirmed by
soil or tissue analysis.
To encourage successful establishment,
it is best to allow newly planted trees
to sway gently in the wind.
Staking should not be used unless the
site is typically very windy and there
is a chance that the rootball may uproot
or become loose in the planting hole.
Long term success of the replacement tree
can be enhanced by establishing and
implementing a consistent preservation
maintenance program that minimizes abrupt
changes in tree care or to the landscape
around it.
While all trees will eventually deteriorate
and need to be removed, using strategies
covered in this video,
will foster the preservation of
landscapes and associated cultural
resources at historic properties.
We hope this video has been helpful
in explaining the concepts and techniques
for replacing trees in historic landscapes.
If you would like additional information
please see the National Park Service
publication “Clippings” available online.