2. 128 Landscape Journal 33:2
Biological Survey 2014). The two largest sources of
plant imperilment are habitat degradation/loss and
alien species establishment (Wilcove et al. 1998). In the
Continental United States, habitat degradation/loss
affects 90% of imperiled plants and alien species affect
30%. In contrast, habitat destruction/loss affects 66%
of imperiled Hawaiian plants and alien species affects
99%.
Importation of Exotic Plant Species into the Hawaiian
Islands
The history of importing exotic plants, those that
are non-native but not necessarily invasive, into the
Hawaiian Islands closely parallels island inhabitation
by humans. These introductions date from 300 CE
when Polynesian voyagers first arrived in the Hawaiian
Archipelago (Cuddihy and Stone 1990). Polynesian
introductions into Hawai‘i are referred to as “canoe
plants,” because they arrived in Hawai‘i in sailing
canoes voyaging across the Pacific (Whistler 2009).
Introduced species have played an important role
in successful human settlement of the islands. Polyne-
sian introductions provided important sources of food
and material for use in home construction and craft-
making to early settlers. The canoe plants assumed
additional value as the islands’ culture evolved. Some
of these species, such as taro (Colocasia esculenta) and
coconut (Cocos nucifera), retain important economic
value as agricultural and horticultural crops to this
day. Some species were able to naturalize in Hawai‘i,
forming self-sustaining populations. Examples include
the candlenut tree (Aleurites moluccanus) that grows
wild in the valleys and has many traditional uses, such
as roasted nuts and oil for waterproofing treatment of
wood.
Diverse Definitions of Native Plants
Purposeful introduction of plants and their natu-
ralization into the Hawaiian landscape confounds
precise definition of the terms “native” and “exotic”
(Brzuszek, Harkess, and Kelly 2010). For example, the
U.S. Fish and Wildlife Service defines native as ‘‘with
respect to a particular ecosystem, a species that, other
than as a result of introduction, historically occurred
or currently occurs in that ecosystem” (U.S. Fish and
Wildlife Service 2001, 2). In contrast, the U.S. National
Park Service defines native plants as “all species that
have occurred or now occur as a result of natural
processes on lands designated as units of the national
park system. Native species in a place are evolving in
concert with each other’’ (U.S. National Park Service
2014, 34). Despite the variation in terminology, com-
mon themes for definitions of native plants typically
emphasize that plants are found to occur in distinct
natural places without the aid of, or introduction by,
humans (Brzuszek, Harkess, and Kelly 2010). The Park
Service definition is more dynamic, allowing syneco-
logical relationships among plants within a community
to potentially impact processes of naturalization and,
thus, potential definitions of the term “native plant.”
Institutional Response to Impacts of Exotic Species in
the Hawaiian Landscape
Irrespective of the capacity of some introduced species
to naturalize and become an integral component of the
Hawaiian landscape, the importation of exotic or alien
species may cause serious environmental impacts. They
can adapt, exploit and modify ecosystems with irre-
versible consequences, particularly in isolated island
ecosystems such as Hawai‘i, where the loss of endemic
biological diversity is a significant ecological challenge
(Denslow 2003; Mack et al. 2000; and Reaser et al.
2007).
In response to the history of exotic species intro-
duction and the dire consequences of these plants
on endemic communities in the state, the continuing
introduction and spread of invasive species, and the
loss and endangerment of native species in the islands,
the Hawai‘i State Legislature passed the Endangered
Species Act 73 in 1992 and the Endangered Species Act
236 in 1993. These laws require the use of Hawaiian
plants (both native and canoe plants) in public projects
in Hawai‘i where appropriate and when these plants
are available.
Public Sentiment for Use of Native Plants
The renaissance of Hawaiian culture since the 1970s
produced a revival of many Hawaiian traditions,
including hula dancing, and use of the lei and tradi-
tional music and chant, as well as herbal medicine
employing native and canoe plants. “[I]n one way or
another, all of these traditions are intimately related
to plant life, and their resurgence has naturally called
attention to the old Hawaiian ways of gathering, cul-
tivating, and using plants” (Abott 1992, xi). Many of
the plants referenced by Abott (1992) are canoe plants.
3. Ricordi et al. 129
As noted, canoe plants are technically not consistent
with institutional definitions of native plants (U.S. Fish
and Wildlife Service 2001, U.S. National Park Service
2000, Brzuszek, Harkess, and Kelly 2010). However,
given the relevance of canoe plants in native Hawai-
ian traditions, the term native plant in this paper will
include canoe plants, introduced in Hawai‘i prior to
Western contact in 1778, as part of the native Hawai-
ian culture (Abott 1992).
The inordinately large impact of alien or exotic
species on Hawai‘i’s endemic flora (CGAPS 2014), the
renaissance of Hawaiian culture (Abott 1992), and
the passage of two Endangered Species Acts spurred
an increase in publicity about native plants and efforts
to promote their cultivation and use in the urban
and rural landscape. These interests are modifying
the operation of the Hawaiian landscape industry,
especially for landscape architects as they consider
abandoning design and contracting practices that have
historically been responsible for introducing and/or
dispersing invasive species (Wilcove et al 1998).
LANDSCAPE ARCHITECTURE IN HAWAI‘I AND ITS
ROLE ON THE PROMOTION OF NATIVE PLANTS
The Pioneering Work of Catherine Jones Richards
The use of native plants by landscape architects in
Hawai‘i dates back to the pioneering work of Cath-
erine Jones Richards, Hawai‘i’s first female licensed
landscape architect, in the 1920s. One of her impor-
tant works was the landscape design for the Honolulu
Academy of Arts, now known as the Honolulu Art
Museum. Richards’ design for the museum involved a
mix of native plants (Pandanus tectorius and Cibotium
glaucum), canoe plants (Cocos nucifera and Cordyline
terminalis) and modern introductions (Bougainvillea
sp.). In a Honolulu Star-Bulletin newspaper article
published on the opening day of the Academy, she
explained her design philosophy for the site (Richards
1927, 3–4):
In making plans for the planting of the grounds of
the Honolulu Academy of Arts, I have tried to keep
two words before me constantly: “Hawaiian” and
“simplicity.” The architecture is so beautiful in its
Hawaiian feeling and simplicity that I have wished
to use only such necessary planting that might set
off and emphasize the building. For this purpose,
material [with] distinct line value has been [used],
so as to give as much design as possible.
As a frame for the whole building I grouped
tall Hawaiian coconut palms. As a ground
planting I have used the green Ape leaf [Alocasia
macrorrhizos]. There is a legend if the ape is
planted on the right of the front door it will bring
good luck to the household, and for good luck’s
sake I have used plenty of it! On the Waikiki side
[East] of the entrance are grouped some old Ti
leaves [Cordyline terminalis], as a sign of welcome,
again conforming to old Hawaiian tradition.
On either corner of the wide front is planted a
group of Lauhalas [Pandanus tectorius] to tie the
whole together. The Lauhala has been chosen by
the academy as its emblem. A tree is a universal
symbol in east or west of life and of knowledge.
The Lauhala tree, being typically Hawaiian
carries the additional suggestion of drawing its
nourishment from many roots.
. . . Rising up on the right hand side of the arch
and banking in the corner of the building is a red
Bougainvillea [Bougainvillea sp.]. This vine was
chosen for its strength and for the contrast of its
colorful blossoms against the gray tiled roof and
the blue sky. As details for the lanais of this court
there are hanging baskets and tree ferns [Cibotium
glaucum—Hapu’u] in Koa [Acacia koa] boxes.
Contemporary Work
As Hawai‘i’s economy developed, landscape services
involving the design, installation and maintenance of
constructed landscapes became more highly valued
and more integrated into various economic sectors.
Currently, there are approximately 50 landscape
architecture firms in the state of Hawai‘i, and nearly
100 licensed landscape architects are affiliated with
the American Society of Landscape Architects Hawai‘i
Chapter (ASLA Hawai‘i 2014). Landscape architec-
ture businesses in Hawai‘i provide services such as
urban and land planning, civil engineering, landscape
architecture, and environmental consulting. Landscape
architects specify plant species for projects across
the state, especially at the larger scales. In specifying
plants for implementation of landscape designs, they
play an important role in effectuating the adoption of
native species.
4. 130 Landscape Journal 33:2
Figure 1
Landscape using Hawaiian plants at
Hale Manoa’s gardens. University of
Hawai‘i at Manoa Campus, Hawai‘i,
USA. (Photo: Alberto Ricordi).
Figure 2
C-MORE Hale entrance, featuring
several native Hawaiian species in
the entrance, both indigenous and
canoe plants. University of Hawai‘i
at Manoa Campus, Hawai‘i, USA.
(Photo: Alberto Ricordi).
Figure 3
Webster Hall renovation project
included a new landscape design,
featuring several native Hawaiian
species, both endemic and
indigenous, as well as exotic plants,
both canoe plants (Polynesian
introductions) and other modern
introductions. University of Hawai‘i
at Manoa Campus, Hawai‘i, USA.
(Photo: Alberto Ricordi).
5. Ricordi et al. 131
Native plants have been extensively incorporated
into recent landscape projects on the University of
Hawai‘i at Manoa campus, including the East-West
Center Native Plants Garden (Figure 1), a Kenzo Ogata
work completed in 1963. The C-MORE Hale building,
(Figure 2), completed in 2012, features both indig-
enous and canoe plants. The Webster Hall renovation,
completed in 2013, is a good example of a contempo-
rary landscape design including native species, both
endemic and indigenous, as well as exotic plants, both
canoe plants (Polynesian introductions) and other
modern introductions (Figure 3).
The use of indigenous and canoe plants in profes-
sionally designed landscapes plays a key role in sup-
plying resources for traditional Hawaiian costumes,
as well as leading to a reduction in the introduction of
exotic and potentially invasive species in the landscape.
Moreover, the use of native plants is identified as a
best management practice for Leadership in Energy
and Environmental Design (LEED), an important
sustainable design certification program in the United
States (USGBC 2011). Native plants are also included
in the “Sustainable Sites Initiative” rating system,
“an interdisciplinary effort by the American Society of
Landscape Architects, the Lady Bird Johnson Wild-
flower Center at The University of Texas at Austin
and the United States Botanic Garden to create vol-
untary national guidelines and performance bench-
marks for sustainable land design, construction and
maintenance practices” (Sustainable Sites Initiative,
2014).
Previous Surveys of Hawaiian Landscape Architects
and Their Perceptions about Using Native Plants in
Design
In the late 1990s, Tamimi (1999) surveyed landscape
architects practicing in Hawai‘i and found that 93%
of the respondents observed an increase in the use
of native plants in their projects during the 1990s.
Primary reasons for this trend were: (i) increase in
awareness (educational, cultural, and general interest);
(ii) laws (related with the Endangered Species Acts 73
and 236); (iii) increase in availability of plants pro-
moted by legalization of their growth and cultivation;
and; (iv) low water requirements associated with native
plants. Tamami also found that 96% of landscape
architects used native plants in their projects because
of: (i) laws; (ii) low maintenance; (iii) appropriateness
for design; (iv) clients’ interests. Constraints most fre-
quently identified as limiting design with native plants
were their lack of availability and the lack of knowl-
edge pertaining to appropriate maintenance practices.
Tamimi’s (1999) findings from Hawai‘i corrobo-
rate research conducted in other parts of the United
States. Potts, Roll, and Wallner (2002) found that
the top concerns of the Colorado’s Green Industry
native plant sector were: propagation, issues of genetic
variability, availability of retail-quality native plant
material, cultural and other information to aid in the
marketing of native plants, the lack of commercially
available seeds, maintenance in landscapes and on res-
toration sites, and finally, public perceptions that often
hinder the acceptance of projects which incorporate
native plants. Research conducted in the southeastern
US and in Utah found similar results relative to the use
of native plants (Brzuszek, Harkess, and Mulley 2007;
Brzuszek, Harkess, and Kelly 2010; Hooper, Endter-
Vada, and Johnson 2008). Lack of plant availability,
client interest, and plant knowledge were identified as
the barriers to increasing the use of native plants in
landscapes in both studies.
The Need for a New Survey of Hawaiian Landscape
Architects
The Hawaiian landscape plant market as well as the
profession of landscape architecture in Hawai‘i have
evolved since Tamimi’s research in 1999. Current
opportunities and barriers relating to the use of native
Hawaiian plants by landscape architects within the
milieu of the contemporary landscape industry are not
well understood. Replication of Tamimi’s work will
help identify needed changes to stimulate increased use
of native plants in public project design both within
the practice of landscape architecture in Hawai‘i as
well as the state’s landscape industry, as required by
Endangered Species Acts 73 and 236. Findings from a
new survey could also facilitate the efforts of the entire
landscape industry in resolving adverse problems asso-
ciated with the plethora of exotic species that continue
to characterize the Hawaiian landscape.
METHODS
Executing the current study consisted of two parts.
Data on the perceptions of Hawaiian landscape archi-
tects were elicited and gathered using a survey. The
6. 132 Landscape Journal 33:2
data gathered in the survey were analyzed using IBM
SPSS Statistics 17.
Data Gathering
In the spring of 2010, 88 members of the Hawai‘i
State Chapter of the American Society of Landscape
Architects (ASLA), received an invitation to partici-
pate in an online survey examining their perceptions
of barriers and opportunities for specifying and using
native Hawaiian plants in landscape design. Partici-
pants recorded their responses to the survey using
a SurveyMonkey format. Although Manfreda et al.
(2008) conclude that, in comparison with mail survey
formats, using an internet-based survey format gener-
ally results in lower response rates, this study adopted
a web-based format as landscape architects are likely
to be proficient in computers and to have internet
access. Design of the 15-question survey instrument
followed Dillman’s (2007) Tailored Design Method.
In addition to requesting information about demo-
graphic and occupational characteristics, the survey
also queried respondents about their experiences in
using native Hawaiian plants in landscape design. Spe-
cific questions focused on the nature of the design proj-
ects for which respondents had specified native plants
and respondent perceptions of the growth in the use of
native plants in the first decade of the 21st century. The
questionnaire also inquired about respondents’ use of
and satisfaction with commercial suppliers of native
plants, as well as their perception of the importance of
various information sources on native plants. It probed
respondent perception of limitations or problems
encountered in previous uses of native plants in land-
scape design projects. Finally, respondents rated their
satisfaction with various aspects of performance of
native plants when used in the landscape designs. The
survey’s format contained both open and fixed format
questions, and the respondents had the opportunity
to include their comments at the end of the question-
naire. Construction of the questions paralleled that
used in previous surveys in Hawai‘i (Tamimi 1999)
and other locations in the US (Potts, Roll, and Wallner
2002; Brzuszek, Harkess, and Mulley 2007; Brzuszek,
Harkess, and Kelly 2010; and Hooper, Endter-Vada,
and Johnson 2008).
The 88 members of the ASLA Hawai‘i State
Chapter received an email message inviting their par-
ticipation in the survey. The message contained a brief
description of the research, a link to access the survey’s
webpage, and human subjects information on matters
relating to privacy and confidentiality. Chapter mem-
bers received four additional email message reminders
to participate in the survey, as Millar and Dillman
(2011) note that sequential email invitations improve
response rates. After 31 days, the survey’s web link was
disabled. A final message was sent to announce the end
of the survey, and to acknowledge the responses and
the ASLA collaboration.
Data Analysis
After downloading the survey responses from the
SurveyMonkey website into an Excel spreadsheet, data
analysis involved use of one-way analysis of variance
(ANOVA) to identify questions in which there were
significant (p < .05) differences in mean values for
individual question items. For questions containing
significant differences, application of Tukey’s honest
significant difference (HSD) post hoc test permitted
identification of homogeneous (p < .05) subsets of
response items. Finally, calculation of correlation test
statistics enabled verification of interaction between
responses from different questions. Calculation of all
test statistics involved use of IBM SPSS Statistics 17
(IBM 2014).
FINDINGS AND DISCUSSION
Response Rates and Respondent Characteristics
A total of 42 respondents completed the entire survey,
providing a response rate of 48.3%. The response
rate of this survey was higher than that obtained
by Tamimi (1999) (40%) in his survey of landscape
architects in Hawai‘i. However, it was lower than
response rates from similar surveys conducted in Utah
by Hooper, Endter-Wada, and Johnson (2008) (55%)
and in the southeastern United States by Brzuszek,
Harkess, and Mulley (2007) (65%).
The geographical distribution of responses (ques-
tion 1) is proportional to the population of each of the
Hawaiian islands, suggesting that the survey included
an accurate spatial coverage of the entire state. Also,
the distribution of responses within the time of survey
corroborates Dillman’s (2007) method, with most of
the responses occurring in the first week, followed
by a gradual reduction of responses until the end of
7. Ricordi et al. 133
Table 1. Respondents’ use of Hawaiian plants in land-
scape design projects for different sectors.
Sector Use score*
Public 3.45
Military 3.11
Residential 3.00
Commercial 2.88
Means compared using Tukey HSD test (p < 0.05). There
were no significant differences (p < 0.05) between sectors.
*Scale: 1 = no use; 2 = low—less than 30% of the projects;
3 = moderate—30 to 60% of the projects; 4 = high—60
to 90% of the projects; 5 = extreme—90 to 100% of the
projects.
the survey (62% of responses during the first week,
14% during the second, 21% during the third, and
3% during the fourth and last week). Highest levels of
education held by the respondents included bachelor’s
degree (64.3%), followed by master’s degree (28.6%)
and high school diploma (4.8%). Over 95% of respon-
dents reported landscape design as their principal
professional concern; 57% also reported involvement
in landscape planning; and 17% indicated profes-
sional engagement in education. Respondents had
been in practice for an average of slightly less than 18
years, and they reported an average of almost 15 years
of experience in using Hawaiian plants in landscape
design.
Demand for Native Plant Use in Hawai‘i
Reponses to questions 7 and 8 reveal that participants
observed a moderate increase in the use of Hawaiian
plants from 2000 to 2010. On a scale ranging from 1
to 7 where the number 1 represented extreme decrease
in the use of Hawaiian plants during this period, 4
represented no change and 7 represented extreme
increase, the mean score across the 42 respondents was
5.45. Respondents observed a deceleration in the rate
of growth in Hawaiian plant use during this period,
but they expected use to increase through 2015. The
deceleration in the perceived rate of growth in the use
of Hawaiian plants between 2000 and 2010 may be
attributable to a downturn in economic conditions
during the later stages of this period.
An increase in use of native plants in landscape
design was also observed by Tamimi (1999) during the
1990s. This momentum is likely a consequence of the
passage of the Endangered Species Acts 73 and 236 of
the 1992 and 1993 Hawai‘i State Legislature, demand-
ing native plants in public projects where appropriate.
Tamimi’s respondents reported using native plants in
Hawai‘i during the 1990s primarily on public projects
(Tamimi 1999) and as a result of the legal mandate
established by these Acts. Other reasons for using
native plants reported by Tamimi’s respondents include
an increase in public awareness, increased availability
of the plants in the nursery industry, and the low water
requirements of the plants. The trend toward higher
levels of native plant use on public sector projects
continued into the 21st century. Table 1 suggests that
respondents to the 2010 survey were more likely to use
Hawaiian plants in public sector projects than in proj-
ects within the residential, commercial and military
sectors, although the differences in reported rates of
use are not statistically significant (p < .05).
The tendency for landscape architects in Hawai‘i
to be more likely to use native plants in public sector
projects is different from trends in the southeastern
United States, where survey respondents reported a
higher likelihood of using native plants in the resi-
dential sector followed by the commercial, municipal,
and federal sectors (Brzuszek, Harkness, and Mulley
2007). In Utah, survey respondents reported using
native plants principally for rehabilitation and recla-
mation purposes (Hooper, Endter-Vada, and Johnson
2008). Brzuszek, Harkness, and Kelly (2010) attribute
this difference in native plants use between the western
and southeastern regions of the United States to the
8. 134 Landscape Journal 33:2
Table 2. Frequency with which survey respondents
purchase or specify Hawaiian plants from
different sources of plants (question 9) and
satisfaction of respondents with suppliers of
Hawaiian plants (question 10).
Source
Frequency*
of purchase
Satisfaction**
with suppliers
Specialized 3.67 a 4.15 a
Retail stores 3.46 ab 3.17 b
General 2.97 b 3.46 b
Garden shops 1.53 c 3.05 b
Means compared using Tukey HSD test (p < 0.05). Fre-
quency and satisfaction scores followed by the same letters
indicate sources are not significantly (p < 0.05) different.
*Frequency Scale: 1 = never; 2 = occasionally; 3 = seldom;
4 = frequently; 5 = always. **Satisfaction scale: 1 = very dis-
satisfied; 2 = dissatisfied; 3 = neutral; 4 = satisfied; 5 = very
satisfied.
Table 3. The opinion of survey respondents on the
importance of several sources of information
about Hawaiian plants (question 14).
Source of information
Importance
Score*
Own experience 4.49a
Specialized nurseries 4.32a
Books 4.19ab
Extension agents/Specialists 3.89abc
Internet websites 3.59cd
Other designers 3.59cd
Training/Conference 3.43cd
Magazine/Newspaper 3.27cd
General nurseries 3.16d
Scientific journal 3.00d
Means compared using Tukey HSD test (p < 0.05). Impor-
tance scores followed by the same letters are not signifi-
cantly (p < 0.05) different. *Scale: 1 = very important; 2 =
important; 3 = moderately important; 4 = of little impor-
tance; 5 = not important at all.
lack of federal and state restoration projects and land-
scape ordinances in the southeastern United States.
These studies suggest that the presence of legal
mandates for use of native plants on public sector
landscape design projects is an important impetus for
increased levels of use. Given the large scale of many
public sector projects and the presence of legal man-
dates for use of native plants in these settings, it is
important that local nurseries be capable of supplying
large quantities of plants. Extensive public projects,
such as institutions, parks, and roadsides, may require
a larger quantity of plants than private projects (com-
mercial and residential sectors). Also, nurseries should
be prepared to meet state and/or federal regulations,
which are different from the regulations for the private
sectors.
Sources of Native Plants in Hawai‘i
Landscape architects in Hawai‘i are more likely to
obtain plants from specialized nurseries rather than
general nurseries or garden shops (Table 2). Respon-
dents were more satisfied with their plant acquisitions
from specialized nurseries than from other suppliers.
This preference for use of specialized nurseries is likely
a function of the actual product (that is, the quality of
the plants) available at these locations, as well as the
fact that specialized nurseries were identified as an
important source of information when using Hawaiian
plants (Table 3). This relationship between specialized
nurseries and landscape architects is also important
in facilitating the introduction of new releases in the
market.
Use of Information Sources about Hawaiian Plants
Table 3 suggests that respondents to the 2010 survey
used a diverse array of sources in gathering informa-
tion about Hawaiian plants and their use in landscape
design. Among the 11 sources listed in Table 3, the
personal experiences of the respondent and nurser-
ies specializing in Hawaiian plants were of greatest
importance in providing information about Hawaiian
plants to survey respondents. Respondents rated books
as well as Extension agents and specialists as impor-
tant sources of information. Sources including internet
websites, other designers, training workshops and
conferences, and magazine/newspaper articles were
of moderate importance, while general nurseries and
scientific journals were rated as of least importance.
9. Ricordi et al. 135
Table 4. The degree of satisfaction of survey
respondents with the performance of
Hawaiian plants when used in landscape
design (question 12).
Category Satisfaction Score*
Water demand 3.72 a
Establishment 3.60 a
Client satisfaction 3.50 ab
Maintenance 3.38 ab
Pests and diseases 3.32 ab
Uniformity 2.97b
Means compared using Tukey HSD test (p < 0.05). Satisfac-
tion scores followed by the same letters are not significantly
(p < 0.05) different. *Scale: 1 = very dissatisfied; 2 = dissatis-
fied; 3 =neutral; 4 = satisfied; 5= very satisfied.
Respondent Satisfaction with Hawaiian Plant
Performance
Table 4 identifies respondent satisfaction with vari-
ous aspects of native plant performance when used
in landscape design. Respondents were most satisfied
with the low levels of water needed to sustain native
plants in landscape designs as well as the ease with
which the plants could be established. Clients appear
to be satisfied with the performance of native plants
in designed landscapes. Respondents recorded at least
moderate levels of satisfaction with the maintenance
requirements of native plants when used in landscape
design and the plants’ ability to accommodate pest and
disease infestations. They reported lowest levels of
satisfaction with the uniformity of the plants.
Landscape architects responding to the 2010
survey were more satisfied with the performance of
shrubs, groundcovers, palms, ferns and trees than with
edible plants and grasses. This may be attributable to
the fact that edible plants demand more maintenance
and most of the grasses used in Hawai‘i are exotic.
There are only two species of palms considered Hawai-
ian, the native Loulu (Pritchardia spp.) and the Polyne-
sian introduction Niu (coconut tree, Cocos nucifera).
Respondents report high levels of satisfaction with
both species.
Respondents reported being least satisfied with the
use of edible and indoor plants. Many edible plants are
canoe plants. Examples include: kalo (taro, Colocasia
esculenta), ‘uala (sweet potatoes, Ipomoea batatas),
niu, ‘ulu (breadfruit, Astorcarpus altilis), mai‘a (Musa
spp.), uhi (yams, Dioscorea species), kō (sugarcane,
Saccharum officinarum), pia (Polynesian arrowroot,
Tacca leontopetaloides), tī (Cordyline fruticosa), āwa
(kava, Piper methysticum). However, when edible
plants are used in public sector landscape designs, they
are generally planted for their aesthetic values (for
example C. esculenta is planted for color and foliage)
or function (for example I. batatais is used as a ground
cover) rather than to be harvested for food. There are
many cultivars of edible plants that have been selected
to accentuate their aesthetic and/or functional values
for landscape use. When planted in residential designs
where the garden is maintained by its owner, edible
canoe plants are more likely to be consumed as food.
This scenario is likely to change with recent
efforts to promote food production in Hawai‘i, includ-
ing in school yards and community parks. A possible
10. 136 Landscape Journal 33:2
Table 5. Perception of survey respondents regarding possible limitations
for the use of Hawaiian plants in landscape design (question 13).
Limitations Perception Score*
Plant size not available 4.10a
Desired species not available 3.72ab
Limited knowledge on propagation and care 3.64ab
Low diversity is available 3.64ab
Limited knowledge on plant use 3.62ab
Unfamiliarity 3.59ab
Clients perception 3.58ab
Cost too high 3.00 bc
Plants in landscape do not correspond design 2.83 c
Poor quality of plants available 2.75c
Means compared using Tukey HSD test (p < 0.05). Perception scores followed by
the same letters are not significantly (p < 0.05) different. *Scale: 1 = strongly dis-
agree; 2 = disagree; 3 = neutral; 4 = agree; 5 = strongly agree.
solution to increase satisfaction with the use of edible
plants could be to increase training in their proper use
in landscape design, especially regarding plant growth
cycles (for example timing of fruit appearance) and
maintenance. Also, some cultivars selected for orna-
mental qualities, such as I. batatais and C. esculenta,
may not be as effective for food production as the
traditional Hawaiian selections, but they could be used
for their ornamental qualities in compositions and
display gardens. Nevertheless, landscape architects
should be aware of the differences between new variet-
ies and the original Hawaiian selections, especially
when using these plants because of their cultural and
historical value or in a landscape in which food is to be
harvested.
The satisfaction of landscape architects with
grasses can be increased with the promotion of suit-
able species and development of techniques for their
use in the landscape industry. Techniques that improve
the establishment success of new plantings and reduce
planting and maintenance costs are essential for adop-
tion of Hawaiian grasses as replacements for tradi-
tional exotic species, or for specialized applications
such as erosion control. Recent studies have developed
and tested different methods of establishing plantings
of native Hawaiian grasses (Baldos 2009, USDA 2010).
Hydroseeding has proven to be a suitable method for
large-scale establishment of Fimbristylis cymosa, a
native Hawaiian sedge that can be used in extensive
plantings such as roadsides (Sakamoto 2008).
Limitations on the Use of Native Plants in Landscape
Projects in Hawai‘i
Table 5 suggests that the main limitations for using
Hawaiian plants in landscape design in Hawai‘i in
2010 are similar to those elicited in the 1999 sur-
vey (Tamimi 1999). In both surveys, key limitations
included: a) limited availability of desired species and
plant sizes; and b) limited knowledge about, and famil-
iarity with, the propagation, care and use of Hawai-
ian plants (Table 5). These same limitations were also
observed as limitations on the use of native plants in
Utah (Hooper, Endter-Vada, and Johnson 2008) and
the southeastern US (Brzuszek, Harkness, and Mulley
2007). Although the propagation and care of plants are
usually the responsibility of nurseries and landscape
contractors, they affect plant selection options for
landscape architects as they limit the designer’s plant
11. Ricordi et al. 137
palette and influence the quality of the landscape after
installation. In the 2010 survey, respondents also rated
client perceptions as a significant limitation on use of
Hawaiian plants in landscape design.
Of special interest in the findings of the 2010 sur-
vey is the fact that relative to the significance of limita-
tions posed by plant availability and limited knowledge
of plant use and care, plant cost was not perceived
as a significant limitation on use of Hawaiian plants.
While cost of plants was also not rated as a significant
limitation on the use of native plants in Utah (Hooper,
Endter-Vada, and Johnson 2008), in the southeastern
US the cost of plants ranked third of eleven as limita-
tions on the use of native plants in landscape design
(Brzuszek, Harkness, and Mulley 2007).
The quality of the plants available in the
nursery industry was also not considered as an
important limitation on the use of Hawaiian plants
in landscape design by respondents to the 2010
survey. The same response pattern was observed in
the use of native plants in both the southeastern US
(Brzuszek, Harkness, and Mulley 2007) and Utah
surveys (Hooper, Endter-Vada, and Johnson 2008).
These results indicate that, even though there is a
low availability of plants, nurseries are supplying the
market with high quality plant materials at reasonable
prices. More importantly, low availability may
continue to be a barrier in promoting use of Hawaiian
plants in landscape design because landscape architects
may be frustrated by the reality that plants specified
for use in a design are not available in the market.
Client perceptions may be frustrated if plants with
irregular sizes are substituted for originally specified
material in their projects.
This is a difficult situation, especially in Hawai‘i
where the isolation and size of the islands place
a geographic limitation on size of the nurseries
and the range of plants that can be carried in
inventory. It is also difficult for nurseries to keep
large stocks of plants because it results in higher
operational costs, labor demands, and larger areas
of production. Strong and effective communication
between landscape architects and nurseries is needed
to correlate plant specification in the design sector
with plant availability in the nursery industry.
Such communication will also provide nurseries
with adequate lead time to schedule the production
of the necessary amount of desired plants.
Another important constraint is the lack of knowl-
edge about the proper use and maintenance of the
plants in the landscape. If landscape architects and cli-
ents have a bad experience using Hawaiian plants, they
will tend to avoid future use, and promotion of other
Hawaiian plants will become even more difficult. Yet,
extension agents, nurserymen and landscape architects
with experience growing and using Hawaiian plants in
design could educate the public on the proper uses of
Hawaiian plants or be consulted for plant selection.
Overall, the survey responses suggest that neither
the quality nor the cost of Hawaiian plants available
in nurseries is a limiting factor affecting their use in
landscape design. This is important, as it suggests
that while nurseries are unable to satisfy the demand
for Hawaiian plants, they are supplying plants with
good quality at reasonable prices. As noted in Table 3,
designer experience, specialized nurseries, books, and
extension agents/specialists are the main sources of
information used by survey respondents as they con-
sider the use of Hawaiian plants in landscape design.
Yet it appears that these sources remain insufficient as
a means of conveying information relating to the care
and use of Hawaiian plants in landscape design.
The internet is generally seen as a rich source of
material and one of the respondents commented that
“an online library resource” would be very beneficial.
Recent websites such as Native Plants Hawai‘i (http://
nativeplants.Hawai‘i.edu/), created by the University
of Hawai‘i in collaboration with local nurseries and
specialists, may enhance the dissemination of needed
information.
CONCLUSION
Current legislation requires the use of native plants in
public sector projects built within the State of Hawai‘i.
In response to this and other factors, landscape archi-
tects practicing in Hawai‘i observed that the quantity
of Hawaiian plants used in landscape design is grow-
ing, and it is expected to continue to grow during the
next five years. However, the main constraints for use
of Hawaiian plants in 2010 remained the same as in
1999. These constraints are low availability of these
plants and limited knowledge about their use and care
when specified in a landscape design.
The quantity of Hawaiian plants available in the
market could be enhanced by increasing the resources
12. 138 Landscape Journal 33:2
for their production and by increasing the efficiency of
production. Realization of these objectives will require
expansion of land area devoted to their production as
well as increased research devoted to the enhancement
of production efficiency. The diversity of plants will
be increased as nurseries propagate more plants col-
lected from native vegetation or ex situ collections of
Hawaiian plants, such as botanical gardens, or uni-
versity and private collections. In propagating ex situ
collections of plant material, careful records must be
maintained to track the origin of genetic material.
This study identified specialized nurseries as a
key factor for promoting the use of Hawaiian plants
in landscape design. Such nurseries are perceived by
landscape architects as being the most reliable sources
of both plants and information about plant estab-
lishment, as well as their care and use in landscape
design. Books and extension agents/specialists were
also identified as important sources of information
for landscape architects. These sources of plants and
information should be nurtured in attempts to over-
come the insufficient amount of information pertain-
ing to the use of native plants in design of the Hawai‘i
landscape.
The market for using Hawaiian plants in land-
scape design is expanding. Sustained growth of this
market will require additional investment to expand
both the scale and efficiency of Hawaiian plant produc-
tion systems in the nursery industry. It will also require
expansion of information dissemination systems to
make knowledge of Hawaiian plant use in landscape
design more readily available. These actions will sup-
port the landscape industry in implementing mandates
of the Endangered Species Acts 73 and 236 to promote
the integration of Hawaiian plants in public sector
landscape design. They will also build awareness of
and help protect the state’s native ecosystems. Finally,
they will provide a stronger sense of the place that is
Hawai‘i.
REFERENCES
Abott, Isabella A. 1992. La’au Hawai’i: Traditional Hawaiian Uses of
Plants. Honolulu, HI: Bishop Museum Press.
ASLA Hawai‘i. 2014. Find a professional. http://www
.Hawai‘iasla.org/category/find-a-professional [May 02,
2014].
Baldos, Orville C. 2009. Assessment of hydroplanting
techniques and herbicide tolerance of two Native Hawaiian
groundcovers with roadside re-vegetation potential. MS
Thesis, University of Hawai‘i at Manoa, College of Tropical
Agriculture and Human Resources, Department of Tropical
Plants and Soil Sciences, Honolulu, HI.
Bornhorst, Heidi L. 2005. Growing Native Hawaiian Plants: A
How-To Guide For The Gardener. Honolulu, HI: Best Press,
Inc.
Brzuszek, Robert F., Richard L. Harkess, and Susan J. Mulley.
2007. Landscape Architects’ use of native plants in the
Southeastern United States. HortTechnology 17(1):78–81.
Brzuszek, Robert F., Richard L. Harkess, and Lelia Kelly. 2010.
Survey of Master Gardener Use of Native Plants in the
Southeastern United States. HortTechnology 20(2):
462–466.
CGAPS, CoordinatingGrouponAlienPestSpecies.2014. http://
www.cgaps.org/?s=code+of+conduct [May 02, 2014].
COX, Linda J. Cox. 2003. An Update on the Economic Role of
Hawai‘i’s Landscape Services. Cooperative Extension
Service, College of Tropical Agriculture and Human
Resources, EI–5.
Denslow, Julie S. 2003. Weeds in paradise: thoughts on the
invasibility of tropical islands. Annals of the Missouri
Botanical Garden 90: 119–127.
Dillman, Don A. 2007. Mail and Internet Surveys. The Tailored
Design Method. Hoboken, NJ: John Wiley and Sons.
Hawai‘i Agricultural Statistics. 2010. 2010 State of Hawai‘i Data
Book. Honolulu: Hawai‘i Dept. of Business, Economic
Development and Tourism.
Hawai‘i Biological Survey. 2014. Hawai‘i’s Endangered and
Threatened Species Web Site. http://hbs.bishopmuseum
.org/endangered/ [July 16, 2014].
Hawai‘i Biological Survey. 2014 Hawai‘i’s Endangered
Plants. http://hbs.bishopmuseum.org/endangered
/endangeredplants.html [July 16, 2014].
Hooper, Virginia H, Joanna Endter-Wada, and Craig W. Johnson.
2008. Theory and Practice Related to Native Plants: A Case
Study of Utah Landscape Professionals. Landscape Journal
27(1):127–141.
IBM. 2014. SPSS Statistics Base. http://www-03.ibm.com
/software/products/en/spss-stats-base [July 19, 2014].
Mack, Richard.N., Daniel Simberloff, W. Mark Lonsdale, Harry C.
Evans, Michael Clout, and FFakhri A. Bazzaz. 2000. Biotic
invasions: causes, epidemiology, global consequences and
control. Ecological Applications 10: 689–710.
13. Ricordi et al. 139
Manfreda, Katja L., Michael Bosnjak, Jernej Berzelak, Iris Haas,
and Vasja Vehovar. 2008. Web surveys versus other
survey modes: A Meta-Analysis comparing response rates.
International Journal of Market Research 50:79–104.
Mead, Roger, Robert N. Curnow, and Anne M. Hasted. 2003.
Statistical Methods in Agriculture and Experimental Biology.
New York: Chapman & Hall/CRC.
Millar, Morgan M., and Don A. Dillman. 2011. Improving
Response to Web and Mixed-Mode Surveys. Public Opinion
Quarterly, 2011, Vol. 75(2): 249–269.
Native Plants Hawai‘i. 2009. University of Hawai‘i. http://www
.nativeplants.Hawai‘i.edu [May 01, 2014].
Potts, Laurel E., Michael J. Roll, and Stephen J. Wallner. 2002.
Colorado Native Plant Survey—Voices of the Green
Industry. Native Plants Journal 3(2): 121–125.
Reaser, Jamie K., Laura A. Meyerson, Quentin Cronk, Maj
DePoorter, L. G. Eldrege, Edmund Green, Moses Kairo,
Pepetua Latasi, Richard N. Mack, John Mauremootoo,
Dennis O’Dowd, Warea Orapa, Soetikno Sastroutomo, Alan
Saunders, Clare Shine, Sigurdur Thrainsson, and Leliua
Vaiutu. 2007. Ecological and socioeconomic impacts of
invasive alien species in island ecosystems. Environmental
Conservation 34: 98–111.
Richards, Catherine J. 1927. “The Grounds,” The Honolulu
Star-Bulletin, Page 11–12, April 28, 1927. Cited in: Historic
American Landscapes Survey. 2011. Honolulu Academy
of Arts (Chinese, Central and Mediterraean Courtyards).
Washington, DC: U.S. National Park Service.
Sakamoto, Glenn, and Joseph DeFrank. 2008. Finding Ways to
Increase the Large Scale Utilization of Native Hawaiian
Plants for Erosion Control. Hoolehua: Hoolehua Plant
Materials Center. http://www.plant-materials.nrcs.usda
.gov/pubs/hipmcot8077.pdf [May 1st, 2014].
SurveyMonkey. www.surveymonkey.com [August 23, 2011].
Sustainable Sites Initiative. 2014. http://www.sustainablesites
.org [May 25, 2012].
Tamimi, L. 1999. The use of native Hawaiian plants by landscape
architects in Hawai‘i. MS Thesis, Virginia Polytechnic
Institute, Blacksburg, VA. 133 pp.
U.S. Fish and Wildlife Service. 2001. National wildlife refuge
system: Biological integrity, diversity, and environmental
health. Release no. 366. U.S. Fish and Wildlife Service
Transmittal Sheet. Part 601 FW 3. Washington, DC: U.S.
Fish Wildlife Service
U.S. Green Building Council. 2014. HSS4.2 b) Plant one tree,
shrub or native groundcover. http://www.usgbc.org
/credits/reqhss4o2 [April 01, 2014].
U.S. National Park Service. 2000. Chapter 4: Natural resource
management: 4.4.1.3 Definition of native and exotic
species, p. 34. In: 2001 NPS management policies. NPS
D1416. Washington, DC :U.S. Natlional Park Service.
Whistler, W. Arthur. 2009. Plants of the Canoe People: An
Ethnobotanical Voyage through Polynesia. Kalaheo, Kauai,
Hawai‘i: National Tropical Botanical Garden.
Wilcove, David S., David Rothstein,Jason Dubow, Ali Phillips,
and Elizabeth Losos. 1998. Quantifying threats to imperiled
species in the United States. Bioscience 48(8): 607–615.
ACKNOWLEDGEMENTS
This material is based upon work supported by the
Hawai‘i Invasive Species Council (HISC). Any opinions,
findings, and conclusions or recommendations expressed
in this material are those of the author(s) and do not nec-
essarily reflect the views of HISC.
AUTHORS Alberto Henrique Ricordi, M.S., Graduate
Assistant in the Department of Tropical Plants and Soil
Sciences (TPSS) at the University of Hawai‘i at Mānoa
(UHM).
Andrew J. Kaufman, ASLA, MLA, PhD, Associate Profes-
sor and Landscape Specialist at TPSS/UHM.
Linda J. Cox, PhD, Community Economic Development
Specialist in the Department of Natural Resources and
Environmental Management Development at UHM.
Richard Criley, PhD, Emeritus Horticulturist of
TPSS/UHM.
Kheng Tuan Cheah, PhD, Associate Specialist in Nursery
Management at TPSS/UHM.
14. Copyright of Landscape Journal is the property of University of Wisconsin Press and its
content may not be copied or emailed to multiple sites or posted to a listserv without the
copyright holder's express written permission. However, users may print, download, or email
articles for individual use.
![128 Landscape Journal 33:2
Biological Survey 2014). The two largest sources of
plant imperilment are habitat degradation/loss and
alien species establishment (Wilcove et al. 1998). In the
Continental United States, habitat degradation/loss
affects 90% of imperiled plants and alien species affect
30%. In contrast, habitat destruction/loss affects 66%
of imperiled Hawaiian plants and alien species affects
99%.
Importation of Exotic Plant Species into the Hawaiian
Islands
The history of importing exotic plants, those that
are non-native but not necessarily invasive, into the
Hawaiian Islands closely parallels island inhabitation
by humans. These introductions date from 300 CE
when Polynesian voyagers first arrived in the Hawaiian
Archipelago (Cuddihy and Stone 1990). Polynesian
introductions into Hawai‘i are referred to as “canoe
plants,” because they arrived in Hawai‘i in sailing
canoes voyaging across the Pacific (Whistler 2009).
Introduced species have played an important role
in successful human settlement of the islands. Polyne-
sian introductions provided important sources of food
and material for use in home construction and craft-
making to early settlers. The canoe plants assumed
additional value as the islands’ culture evolved. Some
of these species, such as taro (Colocasia esculenta) and
coconut (Cocos nucifera), retain important economic
value as agricultural and horticultural crops to this
day. Some species were able to naturalize in Hawai‘i,
forming self-sustaining populations. Examples include
the candlenut tree (Aleurites moluccanus) that grows
wild in the valleys and has many traditional uses, such
as roasted nuts and oil for waterproofing treatment of
wood.
Diverse Definitions of Native Plants
Purposeful introduction of plants and their natu-
ralization into the Hawaiian landscape confounds
precise definition of the terms “native” and “exotic”
(Brzuszek, Harkess, and Kelly 2010). For example, the
U.S. Fish and Wildlife Service defines native as ‘‘with
respect to a particular ecosystem, a species that, other
than as a result of introduction, historically occurred
or currently occurs in that ecosystem” (U.S. Fish and
Wildlife Service 2001, 2). In contrast, the U.S. National
Park Service defines native plants as “all species that
have occurred or now occur as a result of natural
processes on lands designated as units of the national
park system. Native species in a place are evolving in
concert with each other’’ (U.S. National Park Service
2014, 34). Despite the variation in terminology, com-
mon themes for definitions of native plants typically
emphasize that plants are found to occur in distinct
natural places without the aid of, or introduction by,
humans (Brzuszek, Harkess, and Kelly 2010). The Park
Service definition is more dynamic, allowing syneco-
logical relationships among plants within a community
to potentially impact processes of naturalization and,
thus, potential definitions of the term “native plant.”
Institutional Response to Impacts of Exotic Species in
the Hawaiian Landscape
Irrespective of the capacity of some introduced species
to naturalize and become an integral component of the
Hawaiian landscape, the importation of exotic or alien
species may cause serious environmental impacts. They
can adapt, exploit and modify ecosystems with irre-
versible consequences, particularly in isolated island
ecosystems such as Hawai‘i, where the loss of endemic
biological diversity is a significant ecological challenge
(Denslow 2003; Mack et al. 2000; and Reaser et al.
2007).
In response to the history of exotic species intro-
duction and the dire consequences of these plants
on endemic communities in the state, the continuing
introduction and spread of invasive species, and the
loss and endangerment of native species in the islands,
the Hawai‘i State Legislature passed the Endangered
Species Act 73 in 1992 and the Endangered Species Act
236 in 1993. These laws require the use of Hawaiian
plants (both native and canoe plants) in public projects
in Hawai‘i where appropriate and when these plants
are available.
Public Sentiment for Use of Native Plants
The renaissance of Hawaiian culture since the 1970s
produced a revival of many Hawaiian traditions,
including hula dancing, and use of the lei and tradi-
tional music and chant, as well as herbal medicine
employing native and canoe plants. “[I]n one way or
another, all of these traditions are intimately related
to plant life, and their resurgence has naturally called
attention to the old Hawaiian ways of gathering, cul-
tivating, and using plants” (Abott 1992, xi). Many of
the plants referenced by Abott (1992) are canoe plants.](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)