North Dakota State University * Dickinson Research Extension Center
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XERISCAPE ORNAMENTAL PERENNIAL GRASS TRIAL FOR LOW WATER USE LANDSCAPING

Llewellyn L. Manske, Range Scientist, NDSU, Dickinson Research Extension Center
Jerry C. Larson, Extension Agent, NDSU, Extension Service, Stark-Billings County

Western North America has an increasing problem of providing adequate quantities of clean water for domestic use. A large portion of western municipalities' water supply is used for watering lawns, gardens, and landscape plants. Traditional landscaping frequently selects Kentucky bluegrass lawns and ornamental plants that require large amounts of water to remain beautiful. Several agencies and institutions joined the Associated Landscape Contractors of Colorado and Denver Water in 1981 to develop the concept of "Xeriscape" gardening. Alternatives to the traditional techniques are being examined to develop landscapes that are harmonious with the local environmental conditions and use less water. Homeowners in western North Dakota have experienced the high costs of using domestic water for traditional landscape plants and have become aware of the need for alternative landscaping plants. Grass species in this trial are being tested and examined for use as plant material in low water use landscaping.

The purpose of Xeriscape gardening, or low water use landscaping, is to conserve expensive, precious domestic water by following seven simple commonsense principles.

Low water use landscaping achieves the desired goal of conserving water, money, leisure time, and precious resources while providing healthy, beautiful landscapes that add value to property. Xeriscape gardening combines landscaping with conservation.

Methods

This multi-year trial was designed to test and evaluate native grasses and adopted horticultural grasses as low water use ornamental landscape plants in western North Dakota. Thirteen native grasses and eleven horticultural domesticated grasses (Table 1) were included in this study. The research plots are located at the Dickinson Research Extension Center. These plots are managed with minimum maintenance, little supplemental irrigation water, no fertilizer, no herbicides after plot establishment, and hand rouging of weeds when necessary. The study consisted of three replications (Table 2). The grass plants were evaluated for vigor, ornamental value, seedhead aesthetics, color, and height. Vigor, ornamental value, and seedhead aesthetics were rated on a scale of 0-5 (Table 3). Color was recorded as one of twelve colors (Table 3). Total plant height was recorded as one of three height categories (Table 3). The twenty-four grass entries were randomly placed in plots in three replications (Table 4). Two evaluators rated each grass replication during early, mid, late, and post growing season periods. The statistical methods used to analyze differences between means was a standard paired plot t-test.

Results

Mean evaluation ratings of grass entries are shown in tables 5-7 for mid, late, and post growing season periods for 1998, respectively. The grass entries were not evaluated during the early growing season period of 1998 because that was the establishment period. Plants on replication plots of little bluestem, buffalo grass, Indiangrass, Canada wildrye, sweetgrass, and sand love grass died during the first year of the trial as a result of weakened condition caused by the plants being covered by wood chips for several days and not receiving additional attention to assist the plants recovery. These plants will need to be replaced in the spring of 1999. The mean values of the evaluation ratings of these six grass entries with dead replication plots were determined by two methods. The mean evaluation ratings were determined by including the ratings of the replications with dead plants, and means were determined by including the ratings from only the replications with live plants. Mean evaluation ratings for vigor and ornamental value, which were determined by two methods, are reported in tables 5-7. The seedhead aesthetics ratings also report two mean values. The first value includes data from replications not having seedheads, and the second value includes data from only the replications with seedheads present.

Most of the grass entries increased in vigor and ornamental value from mid to late season periods or remained at high or medium ratings. Vigor and ornamental value decreased for most grass entries from late to post growing season periods (Tables 5-7). Several grass entries, little bluestem, big bluestem, prairie cordgrass, sweetgrass, feather reed grass, ribbon grass, blue lyme grass, sand love grass, giant silver banner grass, zebra grass, red switchgrass, autumn red, altai wildrye, and blue fescue, had medium to high vigor and ornamental value ratings during the post growing season period (Table 7). Most of the grass entries tended to have high seedhead aesthetics value ratings during the period from head emergence to seed development stages (Tables 5-7). A few grass entries, blue grama, prairie sandreed, switchgrass, prairie cordgrass, sand love grass, giant silver banner grass, autumn red, and pampas grass had medium or high attractiveness of seedheads after reaching full maturity and during the post growing season period (Table 7).

Most of the grass entries had distinctive attractive shades of green color during the early, mid, and late growing season periods (Tables 5-6). Many of the grass entries completed senescence during the late and post growing season periods, displaying attractive shades of red, purple, or yellow before turning tan (Table 6-7).

The height categories for the grass entries (Table 8) were determined when the plants were mature and the seedheads had reached maximum height. Mature height of a plant is important when designing landscapes. The trial included three short grass, thirteen mid grass, and eight tall grass entries.

Discussion

This is the first year of a multi-year trial designed to test and evaluate grass entries for use as ornamental plants for low water use landscaping. Most of the grass entries show positive potential for use as low water use landscaping plants. A few grass entries, sand bluestem, Canada wildrye, zebra grass, altai wildrye, and green needlegrass had one or more sample periods with low ratings, but these grass entries should not be dismissed as landscape plants yet because one year of data is not an adequate basis for this determination, and these plants may improve. Some of the other grass entries may not maintain their moderate or high value ratings for the long run under these low maintenance and low supplemental water conditions.

Low water use landscaping, which uses native and/or adopted horticultural plants, is an important alternative to traditional landscaping, which uses plants that require large amounts of domestic water to remain beautiful. The results of this trial will assist homeowners to select ornamental perennial grass plants for use in their low water use landscaping.

Acknowledgment

The authors thank Ron Smith, NDSU Extension Horticulturist, Fargo, for providing plugs of horticultural adopted grass species plant material #13 to 20, for assisting with plot establishment, and for providing consultation during the development of this research project. We thank Craig Armstrong for providing plugs of horticultural adopted grass species plant material #22 and 23 and for providing advice on plot management. We thank USDA Plant Materials Center, Bismarck, for providing plugs of native species plant material # 1 to 12. We thank Mike Knutson, USDA Plant Materials Center, Bismarck, for selection, collection, and delivery of native species plant material plugs and for assisting with plot establishment. We thank Jon Stika, NRCS, Area Agronomist, Dickinson, for making arrangements for native species plant material and for assisting with plot establishment. We thank James Nelson, DREC Animal Scientist, Dickinson, for preliminary preparation of plot area and for providing and spreading wood chips.

Table 1. Experiment identification number, common name, and scientific name of grasses included in xeriscape ornamental perennial grass trial for low water use landscaping.
1 Blue grama 'Bad River' Bouteloua gracilis
2 Little bluestem 'Badlands' Schizachyrium scoparium
3 Buffalo grass 'Bismarck' Buchloe dactyloides
4 Sideoats grama 'Pierre' Bouteloua curtipendula
5 Big bluestem 'Bison' Andropogon gerardi
6 Sand bluestem 'Garden' Andropogon hallii
7 Prairie sandreed 'Gosher' Calamovilfa longifolia
8 Indiangrass 'Holt' Sorghastrum nutans
9 Switchgrass 'Dacotah' Panicum virgatum
10 Prairie cordgrass 'Red River' Spartina pectinata
11 Canada wildrye 'Mandan' Elymus canadensis
12 Sweetgrass   Hierochloe odorata
13 Feather reed grass 'Karl Foerster' Calamagrostis acutiflora
14 Ribbon grass 'Feesey' Phalaris arundinacea
15 Blue lyme grass   Elymus arenarius
16 Sand love grass   Eragrostis trichodes
17 Giant silver banner grass 'Robustus' Miscanthus sacchariflorus
18 Zebra grass 'Zebrinus' Miscanthus sinensis
19 Red switchgrass 'Rehbraum' Panicum virgatum
20 Autumn red 'Purpurascens' Miscanthus sinensis
21 Altai wildrye   Elymus angustus
22 Pampas grass   Miscanthus sacchariflorus
23 Blue fescue   Festuca cinerea
24 Green needlegrass   Stipa viridula

 

Table 2. Experimental plot description for xeriscape ornamental perennial grass trial for low water use landscaping.
Location: Dickinson Research Extension Center, Dickinson, ND
latitude 46 53'N, longitude 102 49'W, elevation 2,500ft.
Replications: Three; Rep #1 West, Rep #2 Middle, Rep #3 East
Randomized Block Design
Study size: 18' x 36'
Plot size: 3' x 3'
Perimeter border: 3'
Plot arrangement: 2 columns with numbers 1-12 on west side and numbers 13-24 on east side of each replication.
Grass samples: 24 types x 3 reps. = 72 plants
Plug planting date: 5 May 1998 holes 12" diameter, 8" deep, planted as plugs.
Soil: Morton silt loam
Mulch: Wood chips applied at 4" to 6" thickness between plants.
Herbicide treatment: Roundup applied to previously existing grass cover 30 April 1998.
No other herbicides applied.
Fertilizer treatment: No fertilizer applied.
Soil amendments: No soil amendments applied.
Water: 1.0 to 1.5 gallons water applied to each plot within 3.0 hours of planting. Minimum amount of irrigation water applied during growing season.
Weed control: Wood chips used between plants to help prevent weed growth.
Weeds will be hand rogued when necessary.
Pruning: Previous year senescent growth trimmed in early spring prior to rapid growth. Fall leaves of cool season grasses not trimmed.

 

Table 3. Ratings scales used in the evaluation methods of this trial.

Plant Vigor Ratings Scale

5 4 3 2 1 0
robust vigor - medium vigor - low vigor dead
Ornamental Value Ratings Scale
5 4 3 2 1 0
high value - medium value - low value zero value
Seedhead Aesthetic Ratings Scale

5

4 3 2 1 0
high attractiveness -

medium attractiveness

- low attractiveness not present
Color Ratings
1. Drying 5. Bluegreen 9. Yellow Green
2. Dark Green 6. Light Blue 10. Light Red
3. Green 7. Dark Blue 11. Purple
4. Light Green 8. Gold yellow 12. Tan
Height Ratings Categories
Short grass 0.5 to 2.0 feet
Mid grass 2.0 to 3.0 feet
Tall grass 3.0 to 7.0 feet

 

Table 4. Location of grass entries in xeriscape ornamental perennial grass trial for low water use landscaping.
Rep. #1 West Rep. #2 Middle Rep. #3 East
1
Blue
grama
3
Buffalo
grass
23
Blue
fescue
8
Indiangrass
18
Zebra
grass
16
Sand
love grass
4
Sideoats
grama
12
Sweetgrass
11
Canada
wildrye
9
Switchgrass
21
Altai
wildrye
20
Autumn
red
14
Ribbon
grass
15
Blue
lume grass
24
Green
needlegrass
7
Prairie
sandreed
6
Sand
bluestem
23
Blue
fescue
2
Little
bluestem
11
Canada
wildrye
17
Giant silver
banner grass
14
Ribbon
grass
3
Buffalo
grass
5
Big
bluestem
5
Big
bluestem
6
Sand
bluestem
4
Sideoats
grama
22
Pampas
grass
19
Red
switchgrass
2
Little
bluestem
7
Prairie
sandreed
8
Indiangrass
16
Sand
love grass
10
Prairie
cordgrass
22
Pampas
grass
17
Giant silver
banner grass
13
Feather
red grass
16
Sand
love grass
2
Little
bluestem
19
Red
switchgrass
10
Prairie
cordgrass
13
Feather
reed grass
9
Switchgrass
10
Prairie
cord grass
12
Sweetgrass
5
Big
bluestem
8
Indiangrass
4
Sideoats
grama
17
Giant silver
banner grass
18
Zebra
grass
15
Blue
lyme grass
21
Altai
wildrye
1
Blue
grama
15
Blue
lyme grass
19
Red
switchgrass
20
Autumn
red
13
Feather
reed grass
1
Blue
grama
7
Prairie
sandreed
12
Sweetgrass
21
Altai
wildrye
23
Blue
fescue
18
Zebra
grass
3
Buffalo
grass
9
Switchgrass
11
Canada
wildrye
22
Pampas
grass
24
Green
needlegrass
20
Autumn
red
6
Sand
bluestem
24
Green
needlegrass
14
Ribbon
grass

 

Table 5. Mean evaluation ratings of grass entries in xeriscape ornamental perennial grass trial during the mid growing season period, 24 July 1998.
  Vigor Ornamental Value Seedhead aesthetics Color
1 3.7 3.0 2.3/3.5 Green
2 2.7/4.0 /2.5 0 Green
3 2.3 2.5 0.7/2.0 Bluegreen
4 3.7 3.7 2.7/4.0 Green
5 3.7 3.0 1.3/4.0 Green with red
6 2.7 1.7 0 Lt Blue green
7 3.7 2.7 0 Lt Green
8 2.3/3.5 /2.5 0 Green
9 3.7 3.0 1.3/4.0 Dk Green
10 4.0 3.3 0 Dk Green
11 2.7/4.0 /3.5 2.7/4.0 Lt Green
12 2.7 2.0 0 Dk Green
13 3.3 3.3 3.0 Green
14 3.0 3.3 1.0/3.0 Lt Green with whitestripe
15 3.3 3.0 0 Lt Blue green
16 2.0/3.0 /3.0 0 Dk Green
17 4.0 4.3 0 Dk Green with whiteline
18 2.3 2.7 0 Lt Green with yellow patches
19 3.3 3.0 2.0 Lt Green with red
20 3.3 3.0 0 Dk Green
21 2.3 2.3 0 Bluegreen
22 3.7 3.3 0 Lt Green
23 4.7 4.7 0 Dk Blue
24 2.3 2.0 1.7 Green
Split values: includes dead reps./only live reps.
Statistical significance
vigor:
Low 18, 21, 24
High 4, 7, 17, 22, 23
Ornamental value:
Low 6, 21, 24
High 4, 17, 23

 

Table 6. Mean evaluation ratings of grass entries in xeriscape ornamental perennial grass trial during the late growing season period, 16 September 1998.
  Vigor Ornamental Value Seedhead aesthetics Color
1 4.0 3.0 3.0/4.5 Blue green
2 3.0/4.5 2.3/3.5 2.3/3.5 Green with purple
3 2.0/3.0 1.7/2.5 1.3/4.0 Green
4 3.3 3.0 3.0 Green
5 4.0 4.0 4.0 Green with purple
6 3.3 3.3 3.3 Lt Blue green
7 3.7 3.3 2.7/4.0 Green
8 3.0/4.5 2.0/3.0 0.3/1.0 Green with purple
9 4.3 3.7 2.7 Dk Green
10 4.3 4.0 3.3/5.0 Dk Green
11 1.0/3.0 1.0/3.0 1.3/4.0 Green
12 2.3/3.5 2.0/3.0 0 Dk Green
13 2.7 2.7 1.0/1.5 Green
14 4.3 3.7 0 Lt Green with white stripe
15 3.7 3.3 0 Lt Blue green
16 3.0/4.5 3.0/4.5 2.7/4.0 Lt Green
17 4.7 4.7 0 Dk Green with white line
18 3.0 3.0 0 Lt Green with yellow patches
19 4.3 4.3 3.7 Green with purple
20 4.3 4.0 1.3/4.0 Green with fine white line
21 3.0 2.7 0 Lt Blue
22 4.7 4.7 4.7 Green
23 4.3 4.3 0 Lt Blue
24 2.0 1.7 0 Green with drying
Split values: includes dead reps./only live reps.
Statistical significance
vigor:
Low 11, 24
High 17, 20, 22, 23
Ornamental value:
Low 24
High 17,22, 23

 

Table 7. Mean evaluation ratings of grass entries in xeriscape ornamental perennial grass trial during the post growing season period, 2 November 1998.
Vigor Ornamental Value Seedhead aesthetics Color
1 1.7 2.0 2.0/3.0 Tan
2 2.0/3.0 2.0/3.0 1.7/2.5 Lt Green base with purple
3 0.7/1.0 0.7/1.0 0.3/1.0 Tan
4 1.0 1.3 1.3 Tan with Lt Red
5 2.0 3.0 2.7 Lt Red with purple
6 1.7 2.3 2.7 Tan with Lt Red
7 1.7 2.0 2.0/3.0 Lt Green base, yellowgreen,
8 1.0/1.5 1.3/2.0 0.3/1.0 Lt Red
9 2.0 2.3 2.3/3.5 Lt Red and Tan
10 2.3 3.0 2.0/3.0 Green base, gold yellow
11 1.7/2.5 1.3/2.0 1.3/2.0 Dk Green with Tan
12 2.7/4.0 1.7/2.5 0 Lt Green, yellowgreen
13 3.3 2.3 0.7/1.0 Green with red tips
14 3.7 3.7 0 Lt Green with white stripe
15 3.3 2.3 0 Lt Blue green
16 2.3/3.5 2.7/4.0 3.0/4.5 Green with red tips
17 3.7 3.7 1.3/4.0 Dk Green, white line, red tips
18 3.0 3.0 0 Lt Green, yellow patches, Tan
19 2.7 3.3 2.7 Green base, yellowgreen, red
20 2.3 4.0 1.0/3.0 Lt Red
21 3.0 2.7 0 Lt Blue green
22 1.3 3.3 4.0 Lt Red
23 4.0 4.3 0 Dk Blue
24 1.3 1.0 0 Green base, Tan
Split values: includes dead reps./only live reps.
Statistical significance
vigor:
Low
High
Ornamental value:
Low
High

 

Table 8. Plant height category of grass entries in xeriscape ornamental perennial grass trial.
Number

Code

Height Category
1 S Short grass 0.5-2.0 ft.
2 M Mid grass 2.0-3.0 ft.
3 S Short grass 0.5-2.0 ft.
4 M Mid grass 2.0-3.0 ft.
5 T Tall grass 3.0-7.0 ft.
6 T Tall grass 3.0-7.0 ft.
7 T Tall grass 3.0-7.0 ft.
8 T Tall grass 3.0-7.0 ft.
9 T Tall grass 3.0-7.0 ft.
10 T Tall grass 3.0-7.0 ft.
11 M Mid grass 2.0-3.0 ft.
12 M Mid grass 2.0-3.0 ft.
13 M Mid grass 2.0-3.0 ft.
14 M Mid grass 2.0-3.0 ft.
15 M Mid grass 2.0-3.0 ft.
16 M Mid grass 2.0-3.0 ft.
17 T Tall grass 3.0-7.0 ft.
18 M Mid grass 2.0-3.0 ft.
19 M Mid grass 2.0-3.0 ft.
20 M Mid grass 2.0-3.0 ft.
21 M Mid grass 2.0-3.0 ft.
22 T Tall grass 3.0-7.0 ft.
23 S Short grass 0.5-2.0 ft.
24 M Mid grass 2.0-3.0 ft.

 

Appendix 1. Plot number location for xeriscape ornamental perennial grass trial.

Rep. #1 West Rep. #2 Middle Rep. #3 East
1 13 1 13 1 13
2 14 2 14 2 14
3 15 3 15 3 15
4 16 4 16 4 16
5 17 5 17 5 17
6 18 6 18 6 18
7 19 7 19 7 19
8 20 8 20 8 20
9 21 9 21 9 21
10 22 10 22 10 22
11 23 11 23 11 23
12 24 12 24 12 24

 

Appendix 2. Plot location of xeriscape ornamental perennial grasses entries on three replications.
    Rep. #1 Rep. #2 Rep. #3
1. Blue grama 1 22 9
2. Little bluestem 4 7 17
3. Buffalo grass 13 23 4
4. Sideoats grama 2 5 20
5. Big bluestem 5 20 16
6. Sand bluestem 17 24 3
7. Prairie sandreed 6 15 10
8. Indiangrass 18 13 8
9. Switchgrass 8 14 11
10. Prairie cordgrass 20 18 7
11. Canada wildrye 16 2 23
12. Sweetgrass 14 8 22
13. Feather reed grass 7 10 19
14. Ribbon grass 3 16 24
15. Blue lyme grass 15 9 21
16. Sand love grass 19 6 13
17. Giant silver banner grass 9 4 18
18. Zebra grass 21 11 1
19. Red switchgrass 10 19 5
20. Autumn red 22 12 14
21. Altai wildrye 11 21 2
22. Pampas grass 12 17 6
23. Blue fescue 23 1 15
24. Green needlegrass 24 3 12

Reference Literature

Barondeau, D., R. Smith, J. Larson, C. Miller, J. Dohrmann, T. Becker, R. Gaebe, B. Schmidt, J. Buckley, and L. Manske. 1997. Xeriscape plant selection. NDSU Extension Service. Fargo, ND. 22 min. Video tape.

Denver Botanic Gardens. No date. Water-smart gardening. Brochure. Denver Parks and Recreation Department. Denver, CO.

Denver Water. 1996. Xeriscape plant guide. American Water Works Association. Fulcrum Publishing. Denver, CO.

Denver Water. No date. Discover xeriscape. Pamphlet. Xeriscape Colorado Inc., Denver, CO.

Denver Water. No date. Efficient irrigation systems at work. Pamphlet. Office of Water Conservation, Denver, CO.

Hill, L. and N. Hill. 1995. Lawns, grasses and ground covers. Rodale Press, Emmaus, PA.

Plant Materials Center. 1997. Native grasses for prairie landscaping in the Northern Great Plains. Brochure. USDA Natural Resources Conservation Service. Bismarck, ND.


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