The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
Soa-/ John J. Haydu
Alan W. Hodges
Ronald W. Ward
Econoffie pirt ESaon
Report El 02-1
MAY 1 3200
Market Analysis of the Capillary Mat Irrigation
Technology in the Southeastern United States
] institute of Food and Agricultural Sciences
Food and Resource Economics Department
Florida Agricultural Experiment Stations
Florida Cooperative Extension Services
Gainesville, Florida 32611
Market Analysis of the Capillary Mat Irrigation
Technology in the Southeastern United States
by John J. Haydu, Alan W. Hodges and Ronald W. Ward
University of Florida
Institute of Food & Agricultural Sciences
Food & Resource Economics Department
Economic Information Report EI02-01
March 4, 2002
Market Analysis of the Capillary Mat Irrigation Technology
in the Southeastern United States
by John J. Haydu, Alan W. Hodges and Ronald W. Ward'
University of Florida, Food & Resource Economics Department
Revised March 4, 2002
Water use by horticulture businesses is a matter of great public concern. Capillary mats are a technology that
offers significantly improved irrigation efficiency, but acceptance by horticulture producers and retailers has
been slow. A market study was conducted to determine the extent to which nurseries and garden centers in the
southeastern U.S. would be receptive to utilizing capillary mat irrigation. Focus group sessions were conducted
with nursery owners and managers in Florida to better understand issues affecting adoption of the capillary mat
technology. Wholesale growers interviewed in the focus groups were skeptical of the merits of the capillary
mat. Potential problems cited included weed growth from seeds, rooting problems into the mat, excessive heat
from the black-colored matting, improper soil mixes used by the industry, the high initial cost, and a short life
expectancy in Florida. Although reaction was cautious, this small group was not representative of the total
population of growers. A telephone survey was conducted during September-October, 2000 with a total of 491
wholesale nursery firms and 163 retail garden centers located in nine southeastern states. Results of the
telephone survey highlighted three main issues impacting acceptance of the capillary mat system: water
availability and use, production-related factors, and initial cost. Water availability was not an overriding current
concern, but was perceived as a problem emerging 3-5 years in the future. However, given urban population
growth, the fact that nurseries are located close to urban centers, and the inefficiencies associated with overhead
systems, water-conserving technologies will soon have a more prominent position. Production-related factors as
they impact the capillary mat include types and sizes of containers, soil media, and the slope of the nursery
production areas. Most nurseries have production areas that satisfy slope parameters, utilize soil media that is
adequate for capillary rise, and use compatible containers (holes on bottom and size large enough to compress
the mat). This suggests that few cultural practices used by nurseries will have to be changed, making adoption
easier. At current costs, the majority of nurseries were not interested in purchasing the capillary mat, although
27 percent felt it was competitive with similar technologies. Interestingly, 40 percent would consider using it on
a trial basis. Similarly for retailers, 23 percent said the cost was competitive, and 25 percent were interested in
trying it. A probit regression analysis of the expressed willingness by growers to try the capillary mat system
indicated that this decision was significantly influenced by expectations about availability of future water
supplies, whether they used public surface water, the type of containers used, their belief regarding the
technical feasibility of nursery plant subirrigation, the size of production area, and the perceived cost
competitiveness of the technology. In spite of the negative comments from the focus groups, it would seem
prudent to pursue some level of additional research with the capillary mat for wholesale nurseries. This same
recommendation may not be as appropriate for garden centers, as results indicate that costs of use may well
exceed the potential benefits to be derived.
Acknowledgments. This research was supported by Soleno Textiles Techniques, Inc., Quebec, Canada.
Telephone surveys were conducted under subcontract by the University of Florida's Bureau of Economic and
Business Research. Dr. Jim Seal provided a technical review of the manuscript.
'John Haydu is a Professor and Marketing Specialist at the University of Florida's Mid-Florida Research &
Education Center, Apopka, FL. Alan Hodges is an Assistant-In, and Ron Ward is a Professor in the Food &
Resource Economics Department, University of Florida, Gainesville.
The nursery and greenhouse industry in the United States is the sixth largest sector of agriculture, with
wholesale farm-level sales of about $11 billion in 1997 (NASS, 1999).2 The southeast US is an
important region for both production and marketing of ornamental plants because of the favorable
climate and relatively plentiful land and water resources. However, this situation has begun to change
recently as population pressures mount and new housing developments are established. A major reason
for this growth is the prolonged economic expansion that has affected most areas of the United States.
The strong economy has fueled a rise in both commercial and residential developments, including new
roads, schools, hospitals, and other institutional infrastructures required to support expanding
population centers. The combined impact of these developments has been to place unprecedented
pressures on both land and water resources. As a consequence, in the past several years there has been
increased interest by the nursery and greenhouse industry to find more efficient use of these resources,
particularly water. More efficient water delivery is desirable both from a consumption efficiency
standpoint and maintaining water quality. Industrial, commercial, agricultural and residential
pollutants contaminate groundwater directly and indirectly. Once polluted, it may be impossible to
purify the water, or the cost may be too prohibitive to undertake.
Like other agricultural sectors, the nursery and greenhouse industry uses large amounts of water,
fertilizers and chemicals in the production and maintenance of ornamental plants. In fact, because
nursery crop production is highly concentrated, uses large amounts of water per unit area, and is
propagated year-around, the risks of these pollutants reaching groundwater sources is considered higher
than row-crop agriculture (Skimina; Keese, et al). Largely because of these potential risks to both
ground and surface water sources, many new irrigation technologies are being developed and tested
(Haydu & Beeson). One such technology is the capillary mat system which uses sub-irrigation to water
containerized plants. The capillary mat is an absorbent fabric that collects and stores water from
overhead irrigation. The growing media in containers in contact with the mat will absorb water through
the holes in the bottom of the pot and subsequently irrigate the plants in the pot. The capillary mat
technology has been around for more than twenty years, and is still being studied, tested and improved
upon (Smith & Treaster; Werken; Molitar; Beeson & Haydu). However, because of the mat's relatively
high unit cost, applications have been limited to greenhouse production of vegetables and ornamentals,
and outdoor landscape container operations (Prasad; Chanseetis, et al).
Sensitive to these problems, manufacturers have been working on improving the mat's functional
performance and reducing its cost. New proto-types have been released that have addressed both of
these limitations. The objective of this study was to assess the likelihood that nursery owners and
operators in nine southeastern states would be willing to purchase and use the modified capillary mat
system to irrigate their plants. Retail garden centers were also targeted to determine their perceptions as
to the feasibility of this technology for their adoption and use.
2 National Agricultural Statistics Service (NASS), 1999. Census of Agriculture. U.S.
Department of Agriculture, Washington, D.C.
Scope of Work and Methods
To obtain a better understanding of the core issues affecting the potential adoption of capillary mat
irrigation technology, two focus group sessions were conducted in Florida with nursery owners. Focus
group research is based on facilitating an organized discussion with a group of individuals selected
because they were believed to represent a particular class, such as a class of consumers of a product.
Discussion is used to bring out insights and understandings in ways which simple questionnaire items
may not be able to tap. Focus group research has long been prominent in marketing studies (Kotler,
1988). This methodology is useful in providing information necessary for an accurate and effectual
survey instrument. Based on results of the focus group sessions, a questionnaire was developed and
pre-tested with a small sample of firms. After appropriate revisions were made from the pre-tested
instrument, a large-scale telephone survey was implemented that examined the market acceptance of
the capillary mat system. These interviews of wholesale nursery firms were conducted between
September and October, 2000. Surveyed firms were located in the southeastern states of Alabama,
Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, and Tennessee.
Telephone interviews were conducted using an automated, computer-assisted survey technique.
Surveyed firms were qualified as having open field container production of woody ornamentals, and
produced nursery plants for sale in 1999. Interview respondents were qualified as an owner, manager or
other person knowledgeable about purchasing practices of the firm. The survey questionnaire was
reviewed by the University of Florida's Institutional Review Board to assure protection of the rights of
Lists of telephone numbers for growers and retailers in each state were obtained from state government
agencies and industry trade associations. A total of over 10,000 wholesale nursery firms were
registered in these selected states. Telephone numbers were compiled for a sample of 3,597 wholesale
firms, drawn roughly in proportion to the total population of firms in each state. Where possible,
sampling was concentrated on larger firms in order to maximize the share of the total market covered.
At least three attempts were made to contact each firm listed.
The number of survey respondents in each state is summarized in Tables la and lb. A total of 491
wholesale firms were interviewed, representing a sampling rate of slightly under 5 percent. Over 90
percent of wholesale nurseries interviewed were located in four states, with the 61 percent from
Florida, followed by Georgia (17%), North Carolina (8%) and Alabama (7%). This concentration is
reflective of the actual populations in these states. A total of 163 retail garden centers were eventually
contacted in five states, although the predominant states were Florida and Georgia (Table lb). Retail
respondents were more difficult to contact given the smaller populations and the fact that many of the
managers of retail chain stores were not available. The margin of error for estimating the proportion of
firms for a binary (yes-no) variable was determined using the following formula: d = [ t2 x p x q / n]o5,
where d is the relative margin of error (percent), t is the tail area of Student's t distribution, p and q are
the respective proportions of the binary variable, and n is the sample number.3 So, when t = 2.69,
representing an alpha value of 0.05, this expression gives a 95 percent confidence interval for the
estimated proportion of firms that answered "yes" or "no". For the sample sizes in this survey, a margin
of error of plus-or-minus 3 to 5 percent was obtained and reported for each binary variable.
3 Cochran, W.G., 1953. Sampling Techniques, 2nd edition. John Wiley & Sons, New York, pp. 74-75.
Data presented in Tables la and lb indicate that Florida accounted for the majority of respondents for
wholesale nurseries (61 percent), followed by Georgia (15 percent). For retail nursery and garden
centers, Florida and Georgia each accounted for 45 percent of the sample. Because most respondents
were concentrated in these two states (reflective of the actual populations), a state-by-state analysis wa;
not feasible. More fittingly, data were aggregated to represent one large southeastern geographic
region. When relevant, some of the information was examined by size of business.
To evaluate the relative influence of different factors for adoption of the capillary mat technology, the
survey data for wholesale growers were subjected to analysis by probit regression. The analysis was
performed with the TSP software package, version 4.5. The dependent variable for this analysis was
the response to the question "Would you be interested in using a capillary mat on a trial basis", yes (1)
or no (0). Independent variables included both continuous and binary (yes/no) variables.
Table la. Wholesale ornamental plant nurseries surveyed in the southeastern U.S.
State Population Number Firms Number Percent
Wholesale Available Respondents Respondents
Alabama 450 159 34 7%
Arkansas 120 22 3 1%
Florida 6,657 2,177 300 61%
Georgia 1,717 700 76 15%
Louisiana 500 138 12 2%
Mississippi 125 42 8 2%
North Carolina 264 216 37 8%
South Carolina 184 49 10 2%
Tennessee NA 94 11 2%
Total 10,017 3,597 491 100%
Table lb. Retail nursery and garden centers surveyed in the southeastern U.S.
Alabama 6 4%
Florida 73 45%
Georgia 73 45%
Louisiana 2 2%
South Carolina 9 6%
Total 163 100%
Results of Focus Groups
August 8, 2000 at Apopka, Mid-Florida Research and Education Center. The Central Florida
focus group with eight nursery managers, including 4 greenhouse growers and 4 woody ornamentals
growers was convened at 10AM.. Growers generally believed that a 20-year supply of water is assured
in Florida, but that water supply is potentially a problem in the near future. Water tables and lake
levels have been steadily falling in recent years requiring some growers to drill deeper wells. There
was consensus that the state's five Water Management Districts (WMD) will reduce water supplies
available to nurseries. Currently, WMD rules allow about 65 acre-inches per year of water for
nurseries. There is concern about lack of recognition of differing water needs for different types of
plants. Water recovery systems are encouraged by the WMD, but engineering and permitting are time
consuming and complex. NRCS also provides some cost sharing for tail-water recovery systems.
Micro-irrigation of nursery plants is the most efficient system possible. Micro-irrigation is not yet
common in nurseries but probably will be the norm in the future, especially for larger containers (7+
gal). Maintenance of micro-irrigation systems is problematic. Significant improvement in efficiency of
any irrigation system can be achieved through better scheduling. One grower claimed 50 percent water
savings from pulsed irrigation control. Savings in chemical and fertilizer cost is also important for
chemigation and fertigation systems. Regarding the capillary mat system, five of the growers had
experience with this type of system, mainly the OS brand matting. Cost of the OS brand capillary mat
was put at $0.12 to $0.14 per square foot. It was acknowledged that capillary mats can extend intervals
between watering and save water. However, all but one grower had abandoned it due to a number of
problems. One grower still uses a capillary mat for finishing of blooming plants, to avoid wetting
foliage and attendant disease problems. Growers indicated that the level of growing beds is critical for
capillary mats, as low spots will be too wet and high spots are too dry. Weed growth in capillary mats
can be a problem. Black colored matting can increase temperature of plant root zone to excessive
levels. Expected life of matting in Florida is only about 2 years. Use of very fine soil media for proper
capillary rise would be a serious problem. Excessive salts can build-up in soil if bottom-up irrigation is
used exclusively. Fertigation with capillary mat is uncertain. There was also concern that capillary mat
could cause more problems with diseases due to the more humid micro-environment and reduced air
circulation around plant roots. In regard to use of capillary matting by retail garden centers, it was
acknowledged that a more reliable watering system would help to keep plants in better condition and
more salable. However, there is the difficulty that plants purchased from different growers would have
different soil media and capillary rise characteristics. Also, the capillary mat may not be aesthetically
pleasing for display of plants.
August 9, 2000, at Tampa, Tampa Bay Wholesale Growers Association. Gulf Coast focus group
convened with 4 growers of woody ornamentals, in addition to a county agent and grower association
executive. Hillsborough county has a rather critical water supply situation. The southern part of the
county is designated a "water use caution area", where no new wells or consumptive uses are
permitted. Obtaining water use permits from the SWFWMD is extremely time-consuming. The WMD
expects that 30 40 percent of additional water supplies will come from conservation technologies in
agriculture. Some municipalities have even more stringent water use restrictions for landscape
irrigation than the WMD. Current water volumes permitted by the WMD seem to be adequate, if only
because acreage permitted is for gross nursery property, which includes considerable area not
irrigation. Most of the reclaimed water is not reserved for large industrial users. There was consensus
that the situation will get worse in the future. If severe drought continues, water supplies will become
extremely critical in this region. The shortage of water supplies has now reached the point that for the
first time general development and new construction is being limited. Regarding the capillary mat
system, the need for a very fine-textured growing media was seen as a fatal flaw. The typical soil mix
for woody ornamentals is 60 percent pine bark, 30 percent peat, 10 percent sand. This formula has
been developed over many years of painful trials, and to change it in order to utilize the capillary mat
would be unthinkable. In fact, there is a trend toward even more coarse mixes, with 65 percent or mor
of bark. Composition of potting media varies regionally, depending upon local availability of
materials. In other areas of the southeast, they may use 100 percent composted bark media. No outdoo
nurseries in this area currently use a capillary mat system. There was concern about the durability of
the mat. Realistically, it was expected that it would last for only one growing cycle, which could be as
short as 9 months. Accumulation of sediments and floating of mat could be a problem if it is flooded
by heavy rains. A common nursery practice is to plant liners directly in 3 gallon containers, and this
could be difficult with sub-irrigation. Concern was also elicited about the potential for increased
disease problems with the capillary mat.
Results of Telephone Surveys of Wholesale Nurseries
Sales Class. Over half of the nurseries surveyed (51 percent) are classified as "small" producers, with
annual sales under $500 thousand (Table 2). Medium-sized firms had sales ranging from $500
thousand to $2.4 million, representing 29 percent of the sample, and the largest size class (more than
$2.5 million) accounted for only 7 percent. Despite their fewer numbers, the largest producers
generally are responsible for the majority of total industry output.
Acres in Production. A large number of firms (203 or 41 percent) had production areas over 50 acres,
representing the largest size class in terms of physical area (Figure 1). The remaining nurseries were
fairly equally distributed among three smaller classes a middle category with a range of 25 to 49
acres (19 percent), a smaller range of 10 to 24 acres (20 percent), and the smallest category with
nurseries comprising less than 10 acres (13 percent).
Table 2. Number of firms by sales size class, wholesale nurseries surveyed in the southeastern U.S., 2000.
Sales Class Number
Less than $250,000 176 (36%)
$250,000 $499,000 75 (15%)
$500,000 $999,000 74 (15%)
$1 million $2.4 million 67 (14%)
$2.5 million $5 million 20 (4%)
Greater than $5 million 14 (3%)
Don't know, refused, not available 65 (13%)
Total 491 (100%)
a Figures rounded to nearest percent.
Figure 1. Distribution of acreage in field production, wholesale nurseries surveyed in the southeastern U.S.,
Acres in Production
10 to 24
Less than 10
50 or more
Figure 2. Distribution of number of plant species grown or sold, surveyed wholesale nurseries in the
southeastern U.S., 2000.
Number of Plant Species
Category and Percent
1 t 2
Table 3. Plant types produced and share of total production, surveyed wholesale nurseries in the
Southeastern U.S., 2000.
Percent of Total Shrubs, Small Trees and Large Tropical Plants
Production Landscape Landscape
-------------Number Firms -------------
1 to 19% 46 93 45
20 to 39% 46 85 9
40 to 59 % 60 43 8
60 to 79% 59 16 4
80 to 100% 179 70 18
Don't know, refused, NA 19 19 6
Total and % with some 409 (83%) 326 (66%) 90(18%)
Product Mix. In addition to assessing the size and scope of firms through their annual sales and acres
in production, the study also investigated the degree of product diversity. From a strategy standpoint,
some nurseries may concentrate on fewer species and target specific market niches. Others may grow a
much broader spectrum of plants for a more extensive market coverage, or simply use more variety and
selection to better satisfy existing customers. From the data shown in Figure 2, it is apparent that most
nurseries prefer a large product mix over a small one. Forty-one percent of nurseries sampled grew 50
or more species of plants and another 19 percent produced between 25 and 49 species. The remaining
third of nurseries grew fewer than 25 plant species.
Table 3 presents information on the mixture of plant species grown shrubs and small landscape
materials; trees and large landscape materials, and; tropical plants. Of the 491 wholesale growers
interviewed, 409 or 83 percent had at least some production of shrubs and small landscape materials.
The term "some" can be as little as 1 percent or as high as 100 percent for an individual nursery. Two-
thirds of all nurseries had "some" production of trees and large landscape materials, and less than one-
fifth (18 percent) produced "some" level of tropical plants. The remaining data in Table 3 gets more
specific by showing what proportion of total production the three plant categories represent less than
20 percent of total production; 20 to 39 percent; 40 to 59 percent; 60 to 79 percent; and 80 to 100
percent. Several large numbers stand out. For instance, the left hand column shows that 179 firms (36
percent of all firms) had more than four-fifths of total production in shrubs and small landscape
materials. Likewise, the top row of the middle column shows that 93 nurseries (23 percent of all firms)
had less than one-fifth of total production in trees and large landscape materials. Generally speaking
then, it appears that all categories are represented fairly well establishing the diversity of plant
production of nurseries in the southeast. The exception to this pattern is production of tropical plants
which would be concentrated in Florida.
Water Availability. The source of water for the majority (75 percent) of nurseries in the southeast is
groundwater (Figure 3). Public surface water such as lakes, ponds or streams, was the second most
important source (26 percent). Additional minor sources included: 1) private (on-site) surface water (1
percent), 2) municipal potable water supply (3 percent), and 3) municipal reclaimed or recycled water
(2 percent). Only about one-fifth (22 percent) of nurseries indicated that their water was metered
(monitored) by public agencies (Table 4). The degree of monitoring can indicate the extent to which
water is considered a scarce resource by local governments. Apparently for most nurseries (77 percent)
water is not currently an issue.
When asked if water availability was a problem under normal conditions, most (94 percent) nurseries
indicated it was not. However, when asked if it was a problem under drought conditions, nearly one-
quarter (23 percent) stated that it was. Furthermore, a greater number (41 percent) believed that water
would be a future problem for their nursery. Simply stated, although water availability is not a current
problem, given the rapid rise in urban populations in the southeast, and the fact that nurseries are
typically situated close to urban centers, it soon will be a limiting factor for many nursery operations.
Table 4. Summary of responses to water-related questions, wholesale nurseries in the Southeastern
Question Yes No Othera Margin
Is your water metered or otherwise regulated? 22% 77% 1% 3.1%
Is water availability a problem for your nursery
under normal conditions?
Is water availability a problem for your nursery 23 77% 0% 3.1%
under drought conditions?
Do you believe water availability will be a
41% 50% 9% 3.5%
problem for your nursery in the future?
a "Other" category includes "don't know" the answer, or refused to answer the question.
Table 5. Expectation of water problems in the future, and the ranking of problem severity, by sales
class, surveyed wholesale nurseries in the southeastern US, 2000.
Annual Sales Class Percent claiming Rating Scale a
of Nursery water will be a
problem 1 2 3 4 5
Less than $250,000 35% 4 8 23 8 17
$250,000 $499,000 21% 2 4 10 7 12
$500,000 $999,000 18% 1 3 10 6 11
$1 million $2.4 million 16% 1 2 10 12 4
$2.5 million $5 million 5% 0 0 4 0 4
Greater than $5 million 5% 1 1 2 1 4
Percent 100% 5% 11% 33% 20% 31%
a Rating scale of 1 to 5, with one being the lowest (not serious) rank and five representing the highest
rank (very serious).
Figure 3. Sources of irrigation supply for wholesale nurseries in the southeastern U.S., 2000.
Source of Water Supply
SPublic Surface IMunicipal Supply Other
Groundwater Private Surface Municipal Reclaimed
If water was anticipated to be a constraining resource in the future, what size firm would be most
affected? Results of the data show that smaller firms tended to be more concerned than larger ones ove
this issue (Table 5). More than one-third (35 percent) of nurseries in the smallest sales class indicated
future concern. Going up the scale, only 18 percent of firms in the $500 thousand to $1 million class
thought it would be a future problem, and only 5 percent of businesses in the two largest sales classes
(more than $2.5 million). One explanation is that smaller firms may have fewer options available than
larger firms, hence their greater degree of concern. This statement is supported by the rating scale
shown in Table 5. The greatest number of nurseries indicating it would be a serious (rank 4) or very
serious (rank 5) problem were firms with annual sales under $1 million. The final water-related
question asked when in the future water might be constraining. Sixteen percent of nurseries indicated i
would be a problem within a year, 35 percent within 5 years, and 36 percent in ten years or more.
Irrigation Systems and Water Conservation. Nearly all (91 percent) wholesale nurseries in the survey
currently use overhead sprinklers to irrigate their crops. Almost half (44 percent) also indicated that
they use micro-irrigation or drip systems. Typically growers of trees and large landscape plants will use
drip systems on their largest materials due to the wide spaces between containers. This conserves watel
and is economically feasible from a labor efficiency standpoint (checking for clogged emitters) since,
compared to small landscape materials, there are relatively few containers per unit area. Very few (3
percent) nurseries use "ebb & flow" systems and fewer still (1 percent) use capillary mats for irrigation
When asked whether or not their nursery had a water recovery or recycling system, more than one-third
(35 percent) indicated they did. This rather high percentage of growers who utilize a water
conservation technology is interesting when one considers their perceptions of water availability
(discussed above). Given the expense involved in these technologies, it may suggest that there is
greater concern over water or more stringent government regulations than was indicated earlier.
Respondents were asked what type of irrigation system they would use if they were forced to conserve
water because of limited supplies (Table 6a). Over half (57 percent) of the nurseries interviewed
would use micro-irrigation or drip systems to conserve water, and a little more than a third (35 percent)
stated they would invest in a tailwater (runoff) recovery system. An additional 19 percent of nurseries
would opt for cyclic or pulsed irrigation control, and 6 percent would use a capillary mat system.
Table 6a. Responses to question regarding type of irrigation system nursery would use to conserve
water if required, surveyed wholesale nurseries in the southeastern US, 2000.
Irrigation System Percent
Micro-irrigation or drip systems 57%
Tailwater recovery system 35%
Cyclic or pulsed irrigation control 19%
Capillary mat 6%
a Category includes "other" irrigation system, none, don't know,
refused to answer.
To obtain effective capillary rise, a potting material should consist of water-absorbing soil or peat in
addition to the pine bark that most growers use. To determine the potting mixtures nurseries are
currently using, respondents were asked to select one of five different alternative mixes that most
closely matched their own (Table 6b). From the data presented, the most popular soil mix (30 percent
of nurseries) was 50 percent pine bark, 40 percent peat, and 10 percent sand. According to Dr. Richard
Beeson, this would probably be the second best mix alternative for good capillary rise. Dr. Beeson said
"probably" because it depends on the bark size and type of soil used in the mixes. He felt the best mix
would be the one-third pine bark, one-third peat, and one-third soil. However, this was used by only
eight percent of respondents. If we assume these two categories represent the most optimal mix with
respect to the capillary mat, then roughly 40 percent of nurseries would fall in this category. The
researchers would like to emphasize that, as economists, knowledge of this topic is beyond our
expertise, and is therefore left to the judgement of others.
In addition to the type of potting media used, a second important variable influencing the capillary
mat's effectiveness is the type of containers used. Containers with holes on the bottom are preferred to
those on the sides as the soil will be in contact with the water from the mat. Just over half (51 percent)
of producers used this type of container (Table 7a). Forty-nine percent indicated they used containers
with holes in the sides of the pot, but flush with the bottom. Although this type of pot is less effective
with small (lighter) containers, larger and heavier might work. For containers with side holes, only ten
percent of nurseries fell in this category.
A related factor affecting mat efficiency is the size of the container (alluded to above). Small containers
are less effective than larger ones because they are lighter and will not sink into the mat as well as
large, heavier containers. Container size information is presented in Figure 4. Most nurseries (79
percent) utilized the 1-3 gallon size; 55 percent used 5-7 gallon containers; 49 percent used containers 10
gallons or larger; and 34 percent used containers less than 1 gallon.
A final factor affecting mat efficiency is the slope of the production area. Growers were asked what percentage
of their nursery was graded level with less than 5 percent slope. Fifty-two percent of nurseries indicated that
more than half of their nursery satisfied these requirements, 45 percent claimed that three-quarters of the
nursery met this standard.
Table 6b. Type of soil mix used as a potting media, surveyed wholesale nurseries in the southeastern US,
Soil mix that most closely matches
potting media used
50% pine bark, 40% peat, 10% sand 30%
60% pine bark, 20% peat, 20% sand 11%
50% pine bark, 50% sandy loam 1%
75% pine bark, 25% sand or soil 15%
33% pine bark, 33% sand, 33% soil 8%
Other a 34%
Table 7a. Types of containers used in nursery production, surveyed wholesale nurseries in the
southeastern US, 2000.
Type of container used most Percent
Containers with holes in the 51%
bottom of the pot
Containers with holes in the 49%
sides, but flush with the bottom
Containers with holes in the 10%
sides, but above the bottom
Table 7b. Feasibility of irrigating plants through sub-irrigation, surveyed wholesale nurseries in the
southeastern US, 2000.
Based on the type of plants, soil, Percent
and containers used in your
nursery, is sub-irrigation feasible?
Don't know 6%
Figure 4. Size of containers used by wholesale nurseries in the southeastern U.S., 2000 data.
Percent Using Container Size
< 1 Gallon 1 to 3 5 to 7 > 10
Likelihood ofAdoption of Capillary Mat. Three types of questions were solicited to determine
potential interest in and likelihood of adopting this technology. The first question examined receptivity
based on such factors as types of plants produced, soil mixtures used, and the kinds of containers
purchased by the nursery. Roughly one-fourth (24 percent) indicated they were interested and nearly
three-quarters (70 percent) stated they were not (Table 7, right column). When respondents were told
the cost of the capillary mat ($0.33 to $0.41/sq. ft.) and asked if they considered it competitive with
other water-conserving technologies, 27 percent said it was, 50 percent said it was not, and 23 percent
stated they did not know (Table 8, left column).
Table 8a. Acceptance of costs of capillary mat system, surveyed wholesale nurseries in the
southeastern US, 2000.
Consider cost for capillary mat Percent
competitive with other water
conservation technologies? a
Don't know 23%
a The margin of error for this question was 3.1 percent.
However, when this was followed with a question about whether or not they would be interested in
using a capillary mat on a trial basis, 40 percent stated they were and 52 percent were not (Table 8b,
right column). This result might indicate that even though most growers believed it too expensive, a
convincing number felt it was worth further investigation.
Firms stating that the capillary mat was competitive with other technologies (Table 8a) were also
examined by sales class to determine if a particular business size was more receptive to the concept. Ir
general, responses from this sub-sample of 136 firms were fairly evenly distributed across sales classes!
ranging from a low of 20 percent for the $2.5-5 million category to a high of 36 percent for the greater
than $ 5 million in annual sales. From a marketing perspective, this suggests there is no particular
group of firms worth targeting. A different result materialized when asked if the nursery would
consider using the capillary mat on a trial basis. Of the 195 firms indicating interest, the general
tendency was that, the larger the firm, the more likely they were interested. For example, the two
smallest categories (less than $250 thousand; $250-$500 thousand) represented 42 and 45 percent,
respectively. Conversely, the two largest categories ($2.5-$5 million; greater than $5 million)
represented 55 and 70 percent, respectively. For these results, a marketing strategy targeting larger
producers would be more effective than a program that was non-discriminating.
Table 8b. Interested in using the capillary mat system on a trial basis, surveyed wholesale nurseries in the
southeastern US, 2000.
Would you be interested in using a Percent
capillary mat system on a trial basis? b
Don't know 8%
b The margin of error for this question was 3.5 percent
Results of the probit regression analysis of survey variables influencing the likelihood of adoption of
the capillary mat technology by wholesale growers are summarized in Table 8c. The dependent
variable for this analysis was the answer to the question "would you be interested in using a capillary
mat system on a trial basis?", yes (1) or no (0). For a total of 285 usable observations with sufficient
information, 120 respondents, or 42 percent indicated a willingness to try the capillary mat. The overall
goodness of fit of the regression model is indicated by the fraction of correct predictions (0.698). The
independent variables are listed in the table in rank order of their significance in the model (p-value), oi
probability that the magnitude of the effect observed could occur by chance. Variables which had a
statistically significant effect according to conventional standards (p-value less than .05) included 1)
Water Availability Problem Expected in Future [.002], 2) Use Public Surface Water [.013], 3) Use
Other Container Type [.016], 4) Acres Production Area [.022], and 5) Believe Subirrigation Possible
[.026]. In addition, the variable Believe Capillary Mat is Cost Competitive was marginally significant
[.057]. For all these variables, except one, the positive sign of the estimated coefficient indicates that
an answer in the affirmative, and a larger production area means a greater likelihood of adopting the
capillary mat. For the variable Use Public Surface Water, the negative sign of the coefficient indicates
that use of public surface water sources leads to a lower probability of adoption. For each of the binary
(yes/no) variables, the probability of adopting the capillary mat is estimated for the answer of yes (1) or
no (0), and the difference in probability is also given. For the top-ranked variable, Water Availability
Problem Expected in Future, the probability of adopting the capillary mat was 54.8 percent if water
availability was expected to be a problem in the future, and 32.7 percent if it was not expected to be a
problem. The greatest difference in probability of adoption was for the variable Use Other Container
Type, with a probability of adoption of 68 percent if the answer was "yes", and 21 percent if the answer
Table 8c. Factors influencing likelihood of capillary mat adoption by nursery growers in the Southeas
Water Availability Problem Expected in Future
Use Public Surface Water (yes/no)
Use Other Container Type (yes/no)
Acres Production Area
Believe Subirrigation Possible (yes/no)
Believe Capillary Mat is Cost Competitive (yes/no)
Use Ground Water (yes/no)
Estimated Annual Sales Per Acre
Water Metered (yes/no)
Grow Tropicals (yes/no)
Use Municipal Water (yes/no)
Use Other Water Source (yes/no)
Grow Trees (yes/no)
Number Plant Species Produced
Use Soil Mix 50% pine, 40% peat, 10% sand
Have Water Recovery System (yes/no)
Use Overhead Irrigation (yes/no)
Use Containers with Holes in side, flush to bottom
Water Availability a Problem During Droughts
Use Soil Mix other (yes/no)
Use Other Irrigation Technology (yes/no)
Use Soil Mix 50% pine, 50% sandy loam (yes/no)
Use Containers with holes in bottom (yes/no)
Use Soil Mix 75% pine, 25% sand or soil (yes/no)
Use Soil Mix 33% bark, 33% sand, 33% soil
Percent Nursery Level (1-100%)
Grow Shrubs (yes/no)
Use Reclaimed Water (yes/no)
Use Micro Irrigation (yes/no)
Use Containers with holes in side (yes/no)
Water Availability a Problem Normally (yes/no)
Use Private Surface Water (yes/no)
Use Soil Mix 60% pine, 20% peat, 20% sand
Estimate Std. Error t-
of Estimate statistic
0.284 0.091 3.117
P-value Prob. Prob. Diff. Prol
When When 1 (1-0)
[.002] 0.327 0.548
0.552 0.324 -0.228
0.214 0.680 0.466
0.500 0.372 -0.128
-0.067 0.128 -0.525 [.600] 0.461 0.409 -0.053
0.481 0.389 -0.092
0.467 0.404 -0.063
Analysis performed with TSP Version 4.5. Dependent variable is interested in trying capillary mat (1) or not interested (0).
Number of observations = 285; Scaled R-squared = .183791. Number of positive obs. = 120; LR (zero slopes) = 53.7685
[.013]. Mean of dependent variable = .421053. R-squared = .178057. Fraction of Correct Predictions = 0.698
Results for Retail Garden Centers
Size Distribution. The size classes of the 163 retail garden centers interviewed are presented in Figure 5.
Roughly half (49 percent) of the firms had annual sales under $500 thousand, 15 percent had sales between
$500 thousand and $999 thousand, 12 percent between $1 million and 2.4 million, 7 percent between and $2.5
million and $5 million, and 4 percent above $4 million.
Table 9. Descriptive information on retail garden centers surveyed in the southeastern United States, 2000.
Question Number Percent
1. Types of plants sold in garden center.
Landscape shrubs or small trees 106 65%
o Large trees 72 44%
Bedding plants, flowering potted plants, or foliage 143 88%
Other 38 24%
2. How plants are currently watered.
Primarily overhead irrigation 31 19%
Primarily hand watered 84 52%
Combination overhead and hand watering 41 25%
Don't know, NA 2 <1%
3. How reliable is your current irrigation system?
Always reliable 102 64%
Generally reliable, but with occasional problems 43 26%
Frequently unreliable 2 1%
Don't know, NA 16 9%
4. What percent of plant material is discarded on a monthly basis due
to watering problems?
o None 47 29%
0 Less than 10 percent 96 59%
0 10 to19 percent 15 9%
o 20 to 39 percent 0 0
o More than 40 percent 0 0
o Don't know, NA 5 3%
5. Is water availability a problem for your company during normal
Yes 4 2%
o No 159 98%
6. Is water availability a problem for your company during drought
Yes 19 12%
r No 141 .87%
q Don't know, NA 3 1%
7. Do you expect water availability to be a problem in the future?
o No 31 19%
o Don't know, NA 122 75%
Figure 5. Annual sales categories (millions of dollars) of retail garden centers and percent of firms per
Retail Garden Centers Annual Sales
Percent Firms per Size Class
10% -4-v s
$0.5-$0.99 M $2.5-$5 M
< $0.5 M $1-$2.4 M >$5 M
Plant Material and Irrigation. Retail garden centers surveyed (N=163) in this study sold a broad range of both
indoor and outdoor materials. Sixty-five percent indicated they sold landscape shrubs or small trees, 44 percent
sod large trees, nearly nine out often (88%) sold bedding plants, flowering potted plants, or foliage (Table 9).
Less than 20 percent used strictly overhead irrigation to maintain their plants. Rather, the most popular method
was hand watering (52 percent) or a combination of overhead and hand irrigation. Most garden centers were
satisfied with their method of watering. Nearly two-thirds (64 percent) stated that watering was always reliable
and another 26 percent claimed it was "generally reliable", but with occasional problems. Only 1 percent felt
that their current watering method was unreliable. This point of view was supported by responses in question 4
in Table 9. When asked what percent of material was discarded on a monthly basis due to watering problems,
nearly a third (29 percent) stated that nothing was discarded. Another 59 percent claimed that less than 10
percent was thrown out each month.
Water Availability. Question 5 addressed water availability during normal conditions, and question 6 examined
water adequacy under drought conditions. Nearly all (98 percent) of garden centers said there was no problem
under normal conditions. Only 12 percent indicated problems under drought, and 87 percent stated there were
no difficulties. When asked if they believed water problems would surface in the future, a slightly higher
number (19 percent) felt there would be. Of those people believing there would be a future problem (31 of 163
people), the majority (58 percent) felt it was about 5 years away and, unlike nurseries, the severity of the
potential problem was ranked quite low (i.e., 65 percent fell between neutral and the lowest severity ranking).
Table 10. Information related to cultural practices by retail garden centers in southeastern United States, 2000.
Question Number Percent
1. From how many nurseries did you purchase plant
material last year?
None 6 4%
S1 8 5%
S2-3 29 18%
S4-10 44 27%
More than 10 66 40%
Don't know, NA 10 7%
2. How are plants displayed in the garden center?
Primarily on benches 41 25%
Primarily on the ground 9 6%
Combination benches and ground 81 50%
Other 26 16%
Don't know, NA 6 4%
3. Which type of container do you use the most?
Containers with holes on bottom 94 58%
Containers with holes on sides, but flush with bottom 68 42%
Containers with holes on sides, not flush with bottom 20 12%
Other 11 7%
Don't know, NA 3 1%
4. If a capillary mat costs between $0.33 and $0.41 per
square foot, would you consider purchasing it? 37
Yes 98 23%
No 25 60%
Don't know, NA 3 17%
5. Would you be interested in using a capillary mat on a
Yes 41 25%
No 101 62%
Don't know, NA 21 13%
Purchasing Sources, Display Methods and Types of Containers. Most garden centers purchase plant material
from a variety of nurseries (Table 10). More than one-third (40 percent) purchased from 10 or more nurseries,
another 27 percent purchased from between 4-10 nurseries, 18 percent between 2-3, and only 5 percent from a
single source. Typically garden centers display some material on benches and some on the ground. Generally,
larger (landscape) materials are on the ground, and bedding plants, foliage, and small landscape materials are
displayed on benches. Few (9 percent) garden centers display only on the ground, although one-fourth do
exhibit their material solely on benches. Regarding the types of containers used most, 58 percent of garden
centers use pots with holes on the bottom and 42 percent use containers with holes on the sides, but flush with
the bottom (Table 9). Hence, the majority of containers used by garden centers would be compatible with the
capillary mat system.
Capillary Mat. When informed as to the cost of the capillary mat, and asked if they would be willing to
purchase it for use in their garden center, nearly one-fourth (23 percent) affirmed they would and 60 percent
said they would not. A slightly higher percentage (25 percent) stated they would be interested on a trial basis.
Wholesale Growers. Results of the focus group interviews with wholesale growers indicated
significant concern regarding use of the capillary mat system. Potential problems cited included weed
growth from seeds, rooting of plants into the mat, excessive heat from the black-colored matting
damaging roots, the types of soil mixes used by the industry, the need for very flat production surfaces
to avoid dry spots, a high initial cost, and a short (2 year) life expectancy in Florida. Although reaction
was cautious at best, it is important to note this group embodied a very small sample of growers in
Florida, and was therefore not representative of the total population of growers. This was verified in th<
telephone surveys where findings indicated greater interest regarding the potential of this technology.
Results of the telephone survey highlighted three core issues impacting the adoption and use of the
capillary mat system water availability and use, current production-related factors, and the initial
First, water availability was clearly not an overriding current concern, but it seems quite clear that it is
a future concern among nurserymen. The flip side of water availability is consumption efficiency.
Overhead irrigation systems are notoriously inefficient, particularly with larger container sizes. In
effect it is a supply and demand dilemma. Florida has abundant water supplies throughout the state, but
these are dwindling fast due to urban encroachment. Some restrictions are already adversely impacting
nurseries in southwest Florida. States like Georgia and the Carolinas also appear to have adequate
supplies at the present, but their wells are deep and pumping capacity is limited compared to Florida
wells. Nurseries in these areas use water recovery systems, not so much for groundwater protection, but
to reuse water to meet nursery demand. It is anticipated that in the next 3-5 years, most regions in the
southeast will be affected by greater water restrictions making the need for water conserving
technologies more necessary. Concerns about future water supplies were confirmed as the single most
significant issue affecting adoption of the capillary mat technology in the probit regression analysis.
Second, the study examined production-related factors as they impact the capillary mat, including types
and sizes of containers, soil media, and the slope of the nursery production areas. From conversations
with Dr's Caron and Beeson, these factors may fall within acceptable parameters for viable use of the
capillary mat. Many nurseries have production areas that satisfy slope parameters, utilize soil media
that is adequate for capillary rise, use containers with holes on the bottom of the pot, and utilize large
enough sizes to adequately compress the mat. This suggests that few cultural practices used by
nurseries will have to be changed, making adoption easier. The use of other (unspecified) container
types and whether a grower believed that subirrigation of nursery plants is technically feasible had a
significant effect on willingness to adopt the capillary mat.
A third variable impacting adoption of the capillary mat is its cost. At current costs, only 25 percent of
nurseries were interested and 27 percent felt it was competitive with similar technologies. Interestingly,
40 percent would consider using it on a trial basis. This group probably assumed that it would be
provided at no cost. Even so, this does indicate interest in the technology. Growers who believed that
the stated costs for the capillary mat is competitive with other technologies were significantly more
likely to express a willingness to try it.
Given these results, and in spite of the negative feedback from the focus group sessions, it would seem
prudent to pursue some level of additional research with the capillary mat. Although the greatest
current constraint is cost, there are production-related impediments as well, and the fact that nurseries
believe the mat has a short life span, making it even more costly. Future research should address these
issues. Finally, it is important to recognize that although water is inexpensive and abundant for most
nurseries presently, the situation is changing. As water supplies shrink, restrictions mount, and water
costs rise, new technologies that appear expensive today may not be tomorrow.
Finally, since 40 percent of nurserymen indicated interest in the capillary mat system, what might be
the potential market for the states examined? By using a combination of data from several sources,
including this study, a sales forecast can be derived (Table 11). Total area of open nursery crop
production (column 1) is multiplied against the percent of production that is containerized (column 2),
and then again by the percent of nurseries indicating interest in the capillary mat to derive a potential
market of roughly 25,000 acres.
Table 11. Sales forecast to wholesale nurseries for the capillary mat system in southeastern U.S.
State Production Area Percent Percent Firms Market Potential
(Acres) Contaiperized Interested (Acres)
Alabama 5,629 95% 29% 1,565
Arkansas 360 69% 33% 83
Florida 30,161 78% 42% 9,946
Georgia 4,898 69% 42% 1,413
Louisiana 4,012 72% 25% 726
Mississippi 622 87% 25% 135
North Carolina 15,830 58% 30% 2,706
South Carolina 6,409 57% 30% 1,104
Tennessee 31,451 41% 55% 6,948
Total 99,372 24,626
a Production area of nursery crops in the open. Source: USDA, NASS, 1997 Census of Agriculture.
b Percent of total production in containers. Source: Brooker, J.R., R.A. Hinson and S.C. Turner, 2000.
Trade flows and marketing practices within the United States nursery industry: 1998. Southern
Cooperative Series Bulletin.
c Percent of firms interested in purchasing the capillary mat.
Retail Garden Centers. Important variables to consider for adoption of the capillary mat by garden
centers are current irrigation methods, water availability, number of purchasing sources, types of
containers used, and receptivity based on cost. Based on the data, water availability was clearly not a
problem for garden centers, nor was their current watering methods which involves a mix of overhead
and hand watering. This contention is supported by the fact that very little plant material is discarded
because of inappropriate watering. In addition, most garden centers do not anticipate water to be a
problem in the future. The suitability of the capillary mat can be affected by the lack of standardized
plant material. Since most garden centers receive their materials from a variety of nurseries, the types
of containers and the soil mixtures will tend to have a high degree of variability. If pots do not have
holes in the bottom of containers, and if the soil mixture is too course, the capillary mat will not work
effectively. Garden centers will then be compelled to repot those plants not meeting these
requirements, which they would be unlikely to do. Use of the capillary mat must be simple, must not
impair the appearance of the display, and not result in major operating changes of the garden center, as
these would raise the cost of doing business. The cost of the mat itself is another factor. Receptivity by
garden center managers mirrored that of nursery managers about one-quarter said they would
consider using it at the specified cost, and 60 percent said they would not. A slightly higher percentage
said they would be interested in the mat on a trial basis. Overall, given these results, the likelihood of
garden centers embracing this technology appear more remote than for nurseries, not just now, but even
in the future.
Beeson, R.C. and J.J. Haydu. 2002. "Comparison of Laval University Capillary Mats to Other
Landscape Nursery Irrigation Systems." unpublished research report, Inst. Food & Agric. Sci.,
University of Florida.
Chanseetis, C., Y. Shinohara, M. Takagaki, T. Maruo, M. Hohjo, and T. Ito. 1999. "Application of
Capillary Hydroponic'System to Lettuce Growing Under Tropical Climate Conditions. Acta Hort.
Haydu, J.J. and R.C. Beeson. 1997. Economic Feasibility of Micro-irrigating Container-Grown
Landscape Plants." J. Environ. Hort., 15(1):23-29.
Keese, R.J., N.D. Camper, T. Whitewell, M.B. Riley, and P.C. Wilson. 1994. "Herbicide Runoff from
Ornamental Container Nurseries." J. Environ. Quality. (23):320-324.
Kotler, Philip. 1988. Marketing Management: Analysis, Planning, Implementation, and Control. Sixth
Edition, Prentice Hall, Inglewood Cliffs, New Jersey.
Molitar, H.D. 1990. "The European Perspective with Emphasis on Sub-irrigation and Re-circulation of
Water and Nutrients." Acta Hort. (272):337-345.
Prasad, M. 1999. "Evaluation of Woodwastes as a Substrate for Ornamental Crops Watered by
Capillary and Drip Irrigation." Acta Hort. (548):165-173
Skimina, C.A.. 1986. "Recycling Irrigation Runoff on Container Ornamentals." HortScience 21 (1):32-
Smith, E.M. & S.A. Treaster. 1979. "Studies of Capillary Watering of Container-Grown Nursery
Stock." New Horizons. Horticultural Research Institute, Washington D.C. pp. 25-27.
Werken, H. Van De. 1989. "A New Way with Containers." American Nurseryman 170 (2): 42-51.