Native plants for designing outdoor spaces

Native plants for designing outdoor spaces

By: Fiorella Eduardo-Palomino

The use of native plants is an integral part of the sustainable landscaping. The purpose of using native plants surged due to the environmental degradation we are facing and from the awareness of preserving the environment and pursuing the restoration of environmental quality. The native plants are a fundamental part of the original landscape which has been replaced by non-native species, especially in urban areas. Using native plants in designing outdoor spaces allows adding value and functionality, providing a sense of place as well as offering efficiency in the installation, maintenance, and management of the outdoor area.

On the other hand, the perception of the use of native plants has been discussed in papers the last years (Hoyle et al, 2017; Yakub & Tiffin, 2017; Fischer et al., 2011, Özgüner, 2007). Some research indicates that native species may not be as attractive as non-native ornamental plants and the last ones could have similar benefits and might have a positive adaptation to climate change (Hoyle et al, 2017). However, it is necessary more studies that emphasize the interest of the use of native species in designing outdoor spaces. This entry is not contrary to of the use of non-native plants due to both can be used synergistically in the design of outdoor areas. I will review some of the advantages as well as present the disadvantages of the use of native plants in designing outdoor spaces.

Advantages

Some of the benefits of the use of native species include the aesthetic that we can achieve using them, the adaptation that native plants show in a local environment and the ecosystem services they provide. Following four advantages of the use of native plants in outdoor spaces are developed.

1.     Help people tolerate urban stress

People in big cities are affected by the constant stress the daily routine, a good design landscape can help them to tolerate the everyday stress. Using native plants in outdoor spaces of cities can help people to tolerate urban stressors. Ozguner et al. (2007) mention that urban areas which contain native plants allow people to have contact with nature better than landscape designed using non-native species. Kaplan & Kaplan (1989) in their research about environmental psychology found that people find natural scenes aesthetically pleasing because of their balance of continuity and complexity, their sensory stimulation and their cultural and symbolic significance.

2.     Design with sense of place

For a designer, the benefit using native plants in a project may be helpful to conceive the union with the outside landscape. Regarding design using native wildflowers can help us to better connect with the sense of place. For the designer Steven Tupu (LandscapeAustralia, 2017) “the use of native plants in garden design helps to create a connection between the resident of an urban area and the region where they live.” Additionally, naturalistic landscapes may allow people to more easily observe how nature works and to better experience a feeling of freedom (Ozguner et al., 2007).

Figure 1. Rooftop Park wildflower meadow. This design includes native plants from a meadow. Design by Steven Tupu and his landscape firm Terrain

Source: LandscapeAustralia (2017).

3.     Home-site advantage

Another advantage of the use of native plants comes in the installation of the final design. Using native plants adapted to the local conditions of soil, climate, and water will produce a smooth establishment of the plants in the outdoor space.

One example is the species Andropogon gerardii, commonly called “big bluestem,” which is a tallgrass native to southern Illinois. In a research comparing the use of seeds from Kansas between local seeds investigators found than plants from southern Illinois had the largest number of raceme branches per plant and were taller than plants from Kansas (Gibson et al., 2013). Besides, plants for this species shown a home site advantage when it was planted near to other native grasses (Wilson et al., 2016).

Another native plant observed in southern Illinois gardens is Chasmantium latifolium, “Northern sea oats” or “Indian woodoats” (Figure 2), which has a bamboo-like appearance and has a very attractive seed heads in late summer or beginning of fall (University of Illinois Extension). This plant can grow in full shade due to grown naturally under the trees and reseeds very heavily maintaining the population of plants for the following years.

The two perennial kind of grasses mentioned above is an example of the advantage that can show native species on the establishment of a local garden.

Figure 2. Northern sea oats or Indian woodoats, Chasmantium latifolium in the gardens of Southern Illinois University. Photo by: Fiorella Eduardo-Palomino.

4.     Provide ecosystem services

Native plants provide ecosystem services. For example, the use of native plants increases the pollinators around the garden (Johnson et al., 2017 and Williams et al., 2015). Butterflies feed on the floral nectar of flowers while pollinate flowers, same as bees. Wildflower mixes that provide continuous bloom throughout the season may be particularly important to bumble bees which populations declined in several regions of North America (Williams et al., 2015). It is important to consider in the design the bloom season of the native plants. Synchronizing the bloom between the perennial and annual will provide a better environment for pollinators and our outdoor space may provide an extra ecosystem service for the agricultural lands around.

Native plants provide food and shelter for native wildlife. The Illinois Department of Conservation mentions that native plants are naturally adapted to the environment. They provide shelter to butterfly larvae (caterpillars) feed on leaves while adults feed on nectar. Insectivorous birds glean insects off trees or shrubs, and omnivorous birds supplement their diet with seeds, fruits, and young plant buds. Gardens with native plants can provide more food and cover under extreme drought and cold conditions than non-native plants. Gardens and backyards can be designed to provide food and nesting to birds after considering first the human activities and necessities such as family activities, picnics or privacy (Figure 3).

Figure 3. Design that considers native plants (prairie garden, native shrubs, and trees) and wildlife areas (Birds and squirrel feeders)

Source:   Illinois Department of Conservation

Disadvantages:

1.     Allelopathic substances

When a reduction in the vigor of plants in the outdoor space occurs, might be due to some native plants produce allelopathic substances (Murphy, 2002). These chemicals produced for some plants are alkaloids that can reduce the vigor of other plants in the garden. Research about the physiology or phenology of native plants is limited, however, reading or finding information about the native plant we want to use is important to avoid this kind of inconveniences. Asking the providers about the native plants and testing them before using them in our project will be other solutions to avoid native plants that produce allelopathic substances in the outdoor space.

2.     Difficult to identify

Another disadvantage of the use of native plants in designing outdoor spaces may be that native plants are not visually identifiable for the general public (Fischer et al., 2011). It is necessary to have a certain expertise on botany to identify native plants. However, this may be an excellent opportunity to involve people in botany. Some gardens include small signs indicating the scientific and common name of the plants and its origin, without interfere with the entire design.

  

3.     Perceived as non-attractive

  Some studies suggest that people find non-native species more attractive and interesting than native ones, in urban environments (Hoyle et al, 2017). Some native plants used in designing outdoor spaces had not been improved by selection or hybridization as non-native ornamental plants, which have been selected for years for the color or the size of the flowers. Still, native species represent a pool of genetic resources that can be improved by selection as ornamental plants.

Other studies suggest that spaces designed with more native plants sometimes have less evidence of care, and people perceive them as weedy messy and unkept (Özgüner, 2017). This perceptual conflict can be solved by using a good design. Dunnet & Hitchmough (2004) suggest that nature-like vegetation must be strongly informed by aesthetic principles.  In an urban context native plants can be the highlight, producing understood and valued by the public at large (Özgüner, 2017).

4.     Accessibility of seedlings

Some native plants are not accessible as non-native species. Especially with native trees and shrubs that need to have a recommended high to be transplanted, it is necessary to ask a special production to our plant providers and this can increase the costs of a project. For example, Scarone (2016) mentioned that providers of plants in Uruguay use more land to produce non-native ornamental plants and only produce native plants as pre-order and sometimes the contractors need to provide the seeds or collect them for places around which represent an extra cost. However, the demand for the use of native plants increased the last years in Uruguay which may increase the production of native plants as well in future years.

Conclusion:

This paper reviewed some advantages and disadvantages of the use of native species in designing outdoor spaces. The principal benefits such as help people to tolerate urban stress, give to the design sense of place, have a home-site advantage and provide ecosystem services are presented in the review. The disadvantages revised are the presence of allelopathic substances in some native plants, the difficulty of identifying them, the perception of non-attractiveness and the difficulty of finding native seedling. These disadvantages can be overcome increasing the research of native plants in designing outdoor spaces as well as working in the potential they have to become ornamental plants.

References:

Fischer, A., Bednar-Friedl, B., Langers, F., Dobrovodská, M., Geamana, N., Skogen, K., and Dumortier, M. (2011). Universal criteria for species conservation priorities? Findings from a survey of public views across Europe. Biological Conservation, 144(3), 998–1007.

Gibson, D., Sendor, G., Donatelli, J., Baer, S., & Johnson, L. (2013). Fitness among population sources of a dominant species (Andropogon gerardii Vitman) used in prairie restoration. The Journal of the Torrey Botanical Society, 140(3), 269-279. Retrieved October 19^th, 2017 from http://www.jstor.org/stable/43287010

Hitchmough, J.D. and Dunnet. N. (2004). Introduction to naturalistic planting in urban landscapes N. Dunnett, J.D. Hitchmough (Eds.), The Dynamic Landscape, Design, Ecology and Management of Naturalistic Urban Planting, Spon Press, London. pp. 1-22

Hoyle, H., Hitchmough, J. and Jorgensen, A. (2017). Attractive, climate-adapted and sustainable? Public perception of non-native planting in the designed urban landscape. Landscape and Urban Planning. 164: 49-63

Johnson, A. L., Fetters, A. M. and Ashman, T.-L. (2017), Considering the unintentional consequences of pollinator gardens for urban native plants: is the road to extinction paved with good intentions? New Phytol, 215: 1298–1305.

Kaplan, R. and Kaplan, S. (1989). The Experience of Nature. A Psychological Perspective. Cambridge University Press, Cambridge, England

LandscapeAustralia Editorial Desk. (2017). On the edge: Steven Tupu on activism and risk-taking | Landscape Australia. Retrieved October 18, 2017, from https://landscapeaustralia.com/articles/steven-tupu-interview-risk-taking-activism/

Murphy S. (2002), Biochemical and physiological aspects of pollen allelopathy. In: Mallik IA, ed. Chemical ecology of plants: allelopathy in aquatic and terrestrial ecosystems. Boston, MA, USA: Birkhauser Verlag, 245–260.

Özgüner H, Kendle A, Bisgrove R. (2007), Attitudes of landscape professionals towards naturalistic versus formal urban landscapes in the UK. Landscape and Urban Planning 81: 34–45.

Scarone, P. (2016). El uso de especies nativas en el diseño del paisaje en Uruguay. Republic University (Universidad de la Republica). Montevideo, Uruguay. Retrieved October 13^th 2017 from http://www.fadu.edu.uy/proyecto-paisaje/files/2016/10/El-uso-de-especies-nativas-en-diseño-del-paisaje-en-Uruguay-_Scarone-Pablo.pdf

University of Illinois Extension. Shade Tolerant Ornamental Grasses and Grass-Like Plants. Retrieved October 13^th, 2017 from http://extension.illinois.edu/beyond/directory_grasses.cfm

Williams, N. M., Ward, K. L., Pope, N., Isaacs, R., Wilson, J., May, E. A., Ellis, J., Daniels, J., Pence, A., Ullmann, K. and Peters, J. (2015), Native wildflower plantings support wild bee abundance and diversity in agricultural landscapes across the United States. Ecological Applications, 25: 2119–2131.

Wilson, L. R., D. J. Gibson, S. G. Baer, and L. C. Johnson. 2016. Plant community response to regional sources of dominant grasses in grasslands restored across a longitudinal gradient. Ecosphere 7(4): e01329.

Yakub, M. and Tiffin, P. (2017), Living in the city: urban environments shape the evolution of a native annual plant. Glob Change Biol, 23: 2082–2089.