The Arborist's Report

Grand Army of the Republic Cemetery Park

Tree Inventory and Analysis


An inventory count and inspection of all trees 6"diameter or greater is conducted at the Grand Army of the Republic Cemetery Park. This report contains significant information to tree health and vitality.

The attached spreadsheet, table and narrative includes:

i. Plant name (common and specific epithet [genus and specie]).
ii. Plant size (plant height, canopy width and stem caliper- DBH or diameter measured 4.5 feet from the ground).
iii. Condition rating of 10%-100% reflecting current condition and useful life remaining. Higher numbers signify a better condition and a longer remaining useful life.
iv. Specific comments pertaining to current condition.
v. Recommendations of care.

No trees are recommended for removal based on current hazard potential. Native trees include Bigleaf maple, Douglas-fir, Pacific dogwood and Mountain ash.

Tree Count at GAR Cemetery Park

  Common Name Specific Name
Quantity
Maples Bigleaf Maple Acer macrophyllum
2
  Sycamore Maple Acer pseudoplantanus
2
  Red Maple Acer rubrum
1
  Sugar Maple Acer saccharum
4
Horsechestnut Common Horsechestnut Aesculus hippocastanum
1
Cypress Lawson Cypress Chamaecyparis lawsoniana
7
  Blue Lawson Cyrpress Chamaecyparis lawsoniana 'glauca'
2
  Sawara Cypress Chamaecyparis pisifera
4
  Moss Cypress Chamaecyparis pisifera 'Squarrosa'
1
Dogwood Kousa Dogwood Cornus kousa
1
  Pacific Dogwood Cornus nuttallii
1
Spruce Colorado Spruce Picea pungens
4
Flowering Cherry Kwanzan flowering cherry Prunus serrulata 'Kwanzan'
2
  Yoshino flowering cherry Prunus yedoensis
2
Douglas Fir Douglas Fir Pseudotsuga menziesii
1
Oak English Oak Quercus robur
4
  Red Oak Quercus rubra
2
Mountain Ash European Mt. Ash Sorbus aucuparia
1
Elm Southern red elm Ulmus serotina
1
  Dutch elm Ulmus x hollandica
9

SUMMER IRRIGATION

The young trees are suffering most from lack of summer water, specifically the red maple, sugar maples and the kousa dogwood. I recommend regular supplemental watering through the dry summer months, at least every 10 - 14 days. Water to a soil depth of 12 inches.

I recommend avoid watering near the cypress trees during summer months. Pythium and phytophthora, two deadly soil borne fungi, are encouraged by summer watering and particularly enjoy trees in the genus Chamaecyparis.


TURF AND MOWER DAMAGE

Mower damage has occurred on the trunks of some of the trees. To avoid this, and to create a more root-friendly growing site, I recommend removing turf in a circle around the trees and mulching with wood chips 3-4 inches deep. As a guide, create the circular turf-free zone as large a diameter in feet as the tree's trunk is in inches.

PRUNING RECOMMENDED: WHAT DOES IT MEAN?

Pruning is recommended for several trees in the attached spreadsheet. Nearly all the pruning needed is the limited to the removal of dead limbs two inches in diameter and greater. The potential for deadwood falling and hitting a park user is the biggest hazard currently identified by this inspection.


HAZARD TREES

A small handful of trees have included bark at branch attachments. When the bark of adjacent branches or stems is included, it prevents a structurally stronger wood-to-wood attachment. The amount of included bark identified in the inspection is a slight amount for each tree and currently does not pose a significant hazard from failure potential. Monitoring is recommended.


INSECT

Cherry bark tortrix (CBT) is an insect new to this region. (Attached is a fact sheet that will provide more details about this pest.) The larva of this moth feed in the bark of trees in the genus Prunus. This includes the English laurel along the north of the park, and the Portugal laurel hedge surrounding the cemetery, which are both in the cherry family. The current CBT infestation is limited to the flowering cherry trees. If the population soars, the moth begins to lay eggs in the laurels.

There is currently no biological control available. The recommended chemical control is the insecticide Talstar or Tempo applied to drench the frass tubes (see fact sheet) during the first week of October. Repeat applications are made as needed every 3-5 years.


THE ELM TREES

The elm trees growing in this park are unlike any other elms in the region. According to Arthur Lee Jacobson, who has been studying these trees since the 80's, they are genetically separate individuals and not clones of a single cultivar.

Aside from their historic significance in their placement in this park, it is possible that their genetics may play a role in Dutch elm disease (DED ) resistance.

Currently Seattle Parks and Recreation Department are treating the elm trees for DED.

Some of the elms prefer to grow low branches along their trunks. I recommend retaining some low limbs on these trees, rather than trimming them clean.

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