Dan Segal, Pinelands Nursery
While very few nurseries consider themselves “native” nurseries, most nurseries deal with at least a few native species—red maple, pin oak and Clethra are examples. There are really only two broad markets for native plants: restoration and ornamental landscape. In many cases, native plants are available as cultivars, for the same reasons that cultivars are popular for all plants: uniformity, reliability, or the capture of an exceptional trait. This article offers a native plant nursery’s perspective on why not all native plants are compatible with the goals of ecological restoration. A truly ecological restoration should do at least one of the following: provide erosion/sediment control; improve water quality; create or enhance wildlife habitat; return a disturbed natural area to some pre-determined state; and, if all goes well, serve as a source population for some or all of the species planted, allowing them to spread appropriately from the planting site.
Most nurseries don’t fully discern the different sets of “plant values” associated with these two very different markets (restoration and landscape). If you work with native plants at all, it’s critical to consider some of the following values, which are based on the goals of the end user. It will help focus your business, but more importantly, it will improve the quality and integrity of obs in both the restoration and landscape markets.
Values of Ecological Restoration Plants Values of Ornamental Landscape Plants
Origin
Genetics
Provenance
Seed Grown = Genetic Diversity
Function Ecological
Determinant Naturally Occurring
Pedigree
Vegetatively Grown = Uniformity
Aesthetics
Hardiness Zone
Size Small plants ok—let them grow on site
Brand Name Nursery
Bigger the better, for instant impact
Cultivar, patent or nursery
Some integral plant values for ecological restoration :
1) Provenance
—the geographic source of the seed or cuttings; the more local the better
2)
3)
4)
Genetic diversity —helps the plants reproduce, persist, thrive; seed grown plants are essential
Ecological Function —seed for wildlife, or may knit soil; plants not chosen for ornamental traits
Naturally Occurring— should resemble neighboring plant communities, not a “landscape”
5)
6)
Size— Smaller plants with vigorous root systems are fine; let the plants grow on site
Brand— the nursery’s name, reputation and mission are the “brand” that a customer can trust
If your instincts are protesting that the above set of values describes exactly the kind of motley variability you see only in your nightmares, you are right. Most premium landscape nurseries don’t want the entire range of forms of Juniperus virginiana when their customers demand reliable size and habit. Nor would they want to risk that half their crop of the dioecious winterberry holly lack its signature blood-red fruit.
But these two examples make the differences unmistakably clear between the desirable traits of plants for the restoration trade and the landscape trade.
Some integral plant values for the ornamental landscape trade :
1)
2)
3)
Pedigree —parentage or individual history of hybrid or cultivar (nursery, botanic garden, etc.)
Uniformity — vegetative propagation achieves a consistent form and habit
Aesthetics —the basics: showy flowers, fruit, form, foliage, bark, etc.

4)
5)
6)
Hardiness zone —where does it thrive, and what climatic extremes will kill it
Size
—Bigger is usually better, for more immediate impact
Brand —Cultivar, patent or other branding program can be the brand that a customer can trust
Considering the above value sets, a well-grown block of restoration plants may satisfy the ornamental landscape values if care is taken to maintain the plants to a landscape standard (and if anyone wants to use them). However, again considering the above values, if native plants are grown with no concern for provenance or genetic diversity (non-regional stock, cuttings from one plant, or cultivars), the key values of restoration are undermined regardless of how well the block is grown, or how beautiful the crop.
ORIGIN AND GENETICS: THE NITTY GRITTY
From the native plant grower’s standpoint, the most critical values are Origin and Genetics, because these dictate how we grow our native plants. Function and Hardiness Zone are important also, but they dictate which plants are specified on a given ob or which plants you choose to grow for your region. Size does matter, but size changes with time, whereas provenance and method of propagation are irreversible features. And the brand concept refers back to Origin and Genetics also. For the grower, the seemingly complex issues of Origin and Genetics can be distilled into two simple questions: what is the source of your propagules, and what are your methods of propagation?
Origin and Source of Propagules
It is one of the most basic tenets of ecological restoration, and one of the most controversial, that plants should be of local origin. If local stock is not available, plants should be from regional origin. Controversy arises when “local” or “regional” is defined. Usually local refers to a radius of 25-150 miles, while regional may refer to a few states that share similar climate and vegetation patterns—New England, the
Mid Atlantic, or the Southwest US. The more strictly “local” is defined, the less likely the plants will actually be available, at which point a broader definition is usually allowed. Rarely does the grower have enough lead time to collect seed or cuttings from a given population that allows the strict definition of
“local” to work.
The rationale for using local or regional propagules is this: plants evolve with the combined factors of temperature, seasonality, atmospheric humidity, soil types, pathogen levels, etc. Plants that have evolved under any given set of environmental conditions are more likely to succeed on a site governed by those conditions, compared to plants from elsewhere. While not easy to prove, this principle is intuitive, and definitely harder to disprove.
Genetics and Methods of Propagation
A second tenet of ecological restoration is that plants should be grown from seed to maximize genetic diversity. If vegetative propagation is necessary, cuttings or divisions should be taken from enough separate populations to allow for some genetic diversity. The rationale for using seed-grown plants whenever possible, and for maximizing genetic diversity, is this: the more genetic diversity, the better the chance of long-term survival.
The ultimate goal of ecological restoration should be that plants installed persist on site, reproduce, colonize and (sometimes) disperse. Ecological restorations should be designed and installed to succeed! A planting that peters out over a few years is costly, demoralizing and bad publicity for everyone involved.
Plants grown from seed have the best chance of reproducing, and if they disperse, a new local population has been founded from a wide-ranging mix of genes. Conversely, if plants are grown from cuttings or tissue culture, and are all of one genome, they may be all one sex (if the plant is dioecious), or the inbreeding may result in weak offspring if fertilization occurs at all. At best, a new population may be founded, but with very limited genetic diversity.
CULTIVARS
From the above, it should be clear that cultivars are wrong for ecological restoration. They lack the two most critical plant values that define a true restoration plant: a local or regional provenance, and genetic diversity. A cultivar may maintain its ecological function while also offering an aesthetic improvement

over the straight species ( Viburnum nudum ‘Winterthur’ comes to mind). Finally, while the cultivar’s species may naturally occur in the area, it is the provenance, not the species per se, that renders a given crop of plants locally or regionally suitable. This may be a fine detail, but with so many restoration sites lacking basic maintenance and irrigation, every edge helps.
However, cultivars have never been so popular in the nursery industry. The number of cultivars available, and the number of nurseries growing them, is escalating. Straight species are increasingly viewed as unpolished or pedestrian. It is not entirely clear who is leading the charge—landscape architects or growers—but in a short time, cultivars have become the norm, and most competitive nurseries don’t want to be left behind, or perceived as out of touch. In principle the main reason makes sense, and it’s a sign of a thriving ornamental landscape industry. Plant species are variable, and discerning growers can advance horticulture by selecting choice forms. In doing so, growers provide a more refined product, and come across as horticulturally hip. Not all cultivars warrant selection—the profusion is staggering, and many times the extra name is all that distinguishes the cultivar from the species, as far as most people can tell.
But of course, many are worthy.
For restoration or landscape, plants that will do well almost anywhere
Chokeberry ( Aronia spp.) Switchgrass ( Panicum virgatum )
Arrowwood viburnum ( Viburnum dentatum ) Inkberry holly ( Ilex glabra )
Winterberry ( Ilex verticillata )
Virginia sweetspire ( Itea virginica )
Red maple ( Acer rubrum
Redtwig dogwood (
)
Cornus sericea , = C . stolonifera )
Soft rush ( Juncus effusus , believe it or not!) River birch ( Betula nigra )
Species Features
Shrub alders ( Alnus serrulata, A. rugosa ) Form, fall “cones”, winter catkins; prefer moisture but adaptable
Witch hazel ( Hamamelis virginiana ) Spidery yellow flowers in fall, great architecture
Ironwood ( Carpinus caroliniana )
Spicebush ( Lindera benzoin )
Great small tree for shade or sun, notable for form and bark
Early yellow flowers and late yellow aromatic foliage
Big bluestem ( Andropogon gerardii )
Sassafras ( Sassafras albidum )
Winged sumac ( Rhus coppalina )
Steeplebush ( Spiraea tomentosa )
Perennial grass with multi-colored fall foliage, showy seedheads
Yellow flowers early in spring, unusual branching, warm fall color
Adaptable to wet or dry soil, varnished leaves, flaming fall color
Pink flowers in spires, leaves velvety beneath, takes wet or dry
Cinnamon, royal fern ( Osmunda spp.)
Highbush blueberry ( Vaccinium corymbosum )
Give wet areas lush, woodland look; mulch heavily, avoid wind
Arching form, rich textured bark, dainty flowers and edible fruit— likes acidic soil
From the beginning: Restoration Specs and Design
Restoration X Landscape: Hybrid designs
In many cases, the plant list for a restoration project is created by a landscape designer. Like nurseries, designers should have a clear goal in mind when designing a restoration planting. Often a synthesis, or hybrid, is sought, where restoration meets landscape, mixing the two sets of “plant values”. These projects can be the most beautiful, embodying the best of both worlds. But they can also backfire. Even with the best intentions, the effect can be to dilute both sets of plant values. In trying to satisfy the two broad markets of native plant users, a hybrid design can disappoint the ecological restoration purists, because the key values of a restoration planting are sacrificed for what are perceived as misplaced ornamental traits. At

the same time, those who favor more ornamental plantings (incorporating only the showier natives) may also be disappointed, thinking the plant list is still too functional.
Size
Another important issue facing designers is size. Many landscapers, and customers, want large plants for a quick impact. Large size fits well within the value set of the ornamental landscape trade. However, in ecological restoration, smaller stock is the industry standard, for several reasons. Sites may be remote, or natural conditions (mud, creeks) may render handling and installation harder, slower and more expensive.
Lack of availability in large sizes may be a factor. There is also a common belief that smaller stock will acclimate better than larger stock if soil conditions are adverse. When restoration plants are specified at sizes much larger than what the industry supports, the result is usually downsizing to available “standard” sizes, or substitution. Another possibility is that the contractor may find the stock 1,500 miles away. So, where a designer might have intended to improve the planting with impact, by transporting an ornamental landscape value into restoration, the key values of restoration are compromised. Height or caliper becomes the determining factor of the stock’s suitability, rather than provenance and propagation method. The industry will catch up to the demand for larger plants, if such demand exists. But until it does, the basic restoration plant values (seed-grown plants from known regional provenance, with a chosen ecological function, that naturally occur in the area) should continue to guide designers, as well as growers, to specify appropriate restoration plant material.
Conclusion :
It’s important to remember that ecological restoration differs from natural landscaping, habitat gardening, or general ornamental planting. It is a design and planting process that tries to implement some of the most critical principles of ecology and evolution. It is not better than any other type of planting; it’s just different. The values outlined in the paragraphs above are intended to help growers sort out the differences between the various end users of native plants. This is not intended as an indictment of non-ecological uses of native plants, or of the ornamental landscape trade! It is only to clarify the critical values of native plants in restoration work, and to show how certain plant values of the ornamental landscape trade foster corresponding production methods that can make even native plants incompatible with the ecological side of restoration.