Best Management Practices
For a University of Maine campus
arboretum
20 April 2005
This document was
prepared by the University of Maine Campus Arboretum and Beautification
Committee in order to protect campus plantings and to enhance the campus
landscape generally. It has the endorsement of the University
administration, and it is firmly expected that all employees will adhere
to the practices outlined below.
1. A UMaine campus arboretum should
a. be part of a UMaine master plan;
b. be based upon a UMaine arboretum plan, which includes a local concept
for a campus arboretum;
c. be directed by an on-campus director with a budget and with reporting
authority to the UMaine Vice President for Administration and Finance;
d. be extolled by the UMaine administration as a major institutional
asset for instruction, research, recruiting, and fund raising and as
vital to the UMaine mission;
e. be promoted to students and staff in order to enhance respect and
enjoyment and to minimize problems such as soil compaction;
f. be supported by a committee consisting of administrators, faculty
experts, students, and concerned friends; and
g. be supported by fund-raising activities and creation of a Friends
organization.
2. Plant selection should
a. encompass a wide range of criteria,
including biodiversity (in keeping with the Santamour rule of no more
than 10% of any single species; no more than 20% of any single genus; no
more than 30% of any single family), aesthetics, maintenance costs, and
wildlife potential;
b. emphasize native species and avoid invasive exotics for a more
sustainable and environmentally friendly landscape (invasive exotics, as
defined by the Maine Natural Areas Program, should be removed as quickly
as feasible);
c. conform to the latest American Association of Nurserymen "AMERICAN
STANDARD FOR NURSERY STOCK", ANSI-Z60.1-1996 (copies on file in
Facilities Management and in the office of the Vice President for
Administration);
d. avoid aggregations of one species that are susceptible to disaster
from disease (e.g., American elms that once lined the Mall);
e. emphasize trees with a minimum of 2" caliper; and
f. avoid plant material that might cause plant diseases, such as
gooseberries, the alternate hosts for white pine blister rust.
3. Siting of plants should
a. be approved by the campus arboretum
director and by the Campus Arboretum and Beautification Committee;
b. be compatible with other campus priorities, such as safety,
maintenance efficiency, access to buildings and facilities, and the
campus planning, including a UMaine master plan and a UMaine arboretum
master plan;
c. provide for full expression of adult form and not require excessive
pruning to accommodate buildings, sidewalks, power lines, other trees,
and other structures;
d. be made at a depth that is appropriate for the specimen (examples of
plantings at too great a depth and thus showing no trunk taper include
the Tilia cordata 'Greenspire' in front of Rogers Hall and the Celtis
occidentalis in front of Dunn Hall. Soil is often piled on top of the
root ball during the harvest of field-grown trees. When these trees are
wrapped, the extra soil is included. If this soil is not removed prior
to planting, the resulting root system is several inches too deep. In
general, plants should be planted at the same depth they were growing in
the field or in the pot, no deeper.);
e. create, where possible, multispecies aggregations - such as formal
gardens, floral displays, alleys, more or less natural plant
assemblages, and shaded rest spots - that emphasize plant beauty and
value;
f. avoid planting near buildings with large windows large numbers of
trees and shrubs that bear fruit that intoxicates birds that may fly
into windows; and
g. see also 2. b. under plant selection above.
4. General plant care and
maintenance should
a. based on up-to-date, horticulturally
sound practices that incorporate Integrated Pest Management approaches
(appropriate use of biological and chemical controls in the landscape
setting) as much as possible;
b. be carried out by certified professionals (campus trees and shrubs
should only be pruned by professionals who have been certified by the
International Society of Arboriculture and approved by the directors of
the Campus Arboretum and Facilities Management. Before any tree and/or
shrub is pruned the individual must review the process with the Campus
Arboretum director and the Landscape Division Supervisor);
c. include watering newly planted trees and shrubs during the
establishment period, (one year for each inch of tree caliper and one
year for any shrub) by a gentle soaking equal to 1" of water per week
over the entire root zone, unless this is supplied by rainfall;
d. include watering plants that are not yet established or that are
susceptible during periods of drought;
e. when mulching around trees, avoid piling mulch against tree trunks
(which causes moisture to accumulate, leading to insect and disease
infestations) and gradually increase mulch thickness as distance from
trunk increases out to the drip line at minimum, but twice the distance
from trunk to drip line if possible but not where mulching is not
sensible (e.g., trees along the Mall and lining sidewalks); and
f. follow International Society of Arboriculture standards for pruning;
g. not include fertilization at planting or in subsequent years unless
tissue appearance or analysis indicates a nutrient deficiency (Pushing
growth creates less stress tolerant trees. We should be willing to
accept slower growth rates in exchange for stronger trees. Fertilizing
turf is not good for immediately adjacent trees, another good reason to
create "turf-free" boundaries around our trees with mulching.);
h. require labeling woody plantings as much as possible;
i. permit memorials with in-ground monuments only if a gift supporting
the memorial provides maintenance costs for the plantings;
j. minimize damage to plants during snow removal by avoiding snow-plow
contact with tree trunks, tree limbs, and smaller plants and by not
piling snow near trees and plantings; and
k. minimize damage to plants from salt applied to roadways and sideways.
5. Maintenance of infrastructure
that involves significant excavation or other disturbance of soils, and
new construction should
a. avoid disturbing soil within the
drip line of established plantings;
b. situate roadways, sidewalks, walls and other impervious surfaces in
locations that are consistent with efficient traffic patterns and that
minimize negative effects on adjacent plantings; and
c. restore and enrich soils that will support future plantings.
6. This document should be read and
followed by all UMaine employees involved in landscape maintenance and
campus planning.
The UMaine Administration should
support Professional Development Programs in the form of workshops
dealing with specific topics relating to the caring, maintaining,
preserving, and planning of the Arboretum.
7. This document, created in the
fall and winter of 2002-2003, should be updated by the campus arboretum
director and by the Campus Arboretum and Beautification Committee as
needed.
Date of this version: 20 April 2005
(amended with Campus Arboretum and Beautification Committee approval)
