Here is the third and final article in our series of three written by Landworks Studio staff providing information and insight in obtaining a Net-Zero goal for project sites.
The first article, "Taking Irrigation Off the Grid," discussed the challenges and opportunities related to capture-and-reuse irrigation techniques. The second article, " Soils: A Foundation for Achieving Net Zero Run-Off" emphasized the importance of knowing existing soil conditions and modifying profiles as necessary to achieve predictable results. This last article, "The Use of Native Plants" narrates Landworks Studio's philosophy and approach to the use of native vegetation in site design.
The Use of Native Plants by Carisa L. McMullen, PLA
The term "native plant" means different things to different people. This can be a problem when the term "natives" is thrown around casually in discussion. According to the Lady Bird Johnson Wildflower Center, a native plant is "One that exists in a given region through non-human introduction, directly or indirectly." While there is some documentation of specific species of plants associated with prairie communities prior to the first settlers, there is some debate over the influence by Native Americans on these plant communities.
Adapted plants are locally grown varieties that have adapted to our conditions over many, many years. The list of adapted plant materials is longer and the plants are hardy. These plants have developed characteristics that allow them to survive the conditions we find here in our region. The term "adapted natives" is also used to classify this group of plant materials. Although some may not consider these plants true natives, these plants, like the true natives, usually require very little maintenance once established. Adapted plants have many of the same benefits as true natives and may also be more readily available.
Cultivars are plants that have been developed for certain, very specific characteristics. These plants are embraced by the general public because of their flower color, growth habit, texture, size, etc.
Natives are grown locally or regionally so environmental transportation impacts reduced. Natives are better acclimated to our weather patterns and have natural pest resistance; this increases survivability without adding nutrients or pesticides to the environment. The root systems of many native plants will eventually penetrate a wide variety of soil types. These deep roots allow more water absorption into the soil, filter the groundwater and keep the plants vigorous during drought conditions.
Most of us have heard these statements before. What you may not have considered is the impact plant materials can have on an entire ecosystem. Local genotypes increase the possibility of transferring genetic material between plant populations. This is good for plants, insects, birds and other fauna.
Non-native species of plants can confuse other forms of life. Surprisingly, insects can get confused by non-native species of plants if the insects have adapted to a certain plant and/or bloom color, scent or blooming period. Non-natives can have a negative impact below the soil surface, as well. Fungi and plant-pathogen interactions below the surface can be considered "foreign" in an ecological community.
Non-native plants often times require specific soil amendments or special maintenance to keep them healthy or to achieve the desired bloom color, like hydrangea, for instance. Non-natives can also be sterile and may not provide any nutritional benefit to the insects, birds and wildlife in a given area. Invasive species are non-natives and threaten species diversity.
Working with Natives
While there are many benefits to using natives, there are a few minor negatives. Natives may take longer to establish. They may have an unkempt look during grow-in or at maturity. Natives require a different type of maintenance that may require "re-training" or education for the eventual caretakers.
Just as there is no "cookie-cutter" response to site design, the use of natives, with all its benefits, may not be the appropriate solution in every instance. Landworks Studio's approach to the use of native plant materials is consistent from project to project, however. First, we gather information from the site and the owner relative to the specific site program. We will never force a plant palette that will not have a chance for success. Some of the questions we ask early in the design process are:
- Is this something the owner is interested and willing to explore?
- Does the site lend itself to the use of natives?
- Can we achieve the look and feel we are after with the use of natives?
- Does the owner have the patience to wait for optimum results?
If natives are appropriate, then we ask a series of follow-up questions:
- Can the design be maintained to a satisfactory level? Can we provide a maintenance manual to assist in future maintenance?
- Is there an opportunity to add "structure" to the landscape? The structure can be as simple as a solid evergreen shrub mass or hard-edged pavement line. It can be as elaborate as an architectural element or feature. The less manicured look tends to be more visually appealing with an adequate proportion of structure. It is also easier to maintain if there are defined edges to the native plantings.
- Can we include a few commercially recognized plants? One example might be shrub roses. If the user or audience can identify some plants in the mass, the landscape tends to feel more accessible.
A diverse landscape with a wide range of plants selected to fit the site and the preferences of the owner and users is a success. We are able to create a landscape with beauty for years to come by incorporating these principles in our planting design. Included here for your use and information is a list of some Midwestern native plants that can be substituted for common commercial species. For the complete list, request "The Native Planting Handbook" written by the great folks at Taylor Creek Restoration Nurseries or contact the staff at Landworks Studio.