What's better - native straight species or nativars, which do pollinators prefer, and what the heck is the difference anyway?
As proponents of growing native plants, we are excited to see increased interest in them these past few years. We continue to expand and evolve our native plant offerings each season, and do our best to grow both what we think is important from a biodiversity standpoint as well as what our customers are wanting. It can be hard marketing some natives as they may not look like much as a young potted plant, so there's a big market for selling native cultivars with increased ornamental appeal. However, in recent years, we've had many customers ask us to grow more straight species natives. As we've observed native flowers in our gardens as well as those blooming in our greenhouses this summer, we've taken note of which plants seem to be attracting the most pollinators. This led us to doing a bit of research, and we wanted to share our take-away regarding natives versus native cultivars, as it is far from black and white!
First, let’s review some common plant terms that can be a bit confusing!
• NATIVE PLANT (AKA 'straight species'): A plant species that occurs naturally in a particular region, habitat, or ecosystem.
• CULTIVAR: A cultivated variety of a straight species plant - it is a result of artificial selection; humans selected it for a trait perceived as better than those regularly found. The chosen plant is then propagated asexually (taking a cutting or root division to generate new plants that are genetically identical). Some cultivars are found as a “sport” or genetic mutation of the species in the wild, but many are the result of selective breeding by growers.
• NATIVAR: A term used to describe native cultivars - the nativars we sell are typically pretty similar to their straight species parent but all nativars result from some level of artificial selection.
• HYBRID PLANT: The result of a genetic cross between two different plant species - they can sometimes occur naturally, but typically they are the result of breeding by growers. The vast majority of what you see in most garden centers and gardens are hybrids of some sort - many of which have been bred over decades or even centuries! Some hybrids may be crosses of two native species and therefore still provide some great ecological benefits, so they are not always the least beneficial choice for a wildlife garden.
• INVASIVE PLANT: Species that are non-native (often introduced from another continent) and able to establish in a variety of growing sites where they grow quickly and spread fast enough to disrupt and displace the naturally occurring plant and wildlife communities.
What do the names mean on a typical plant label?
On our labels, we typically start with the common name of the plant in regular text followed by a cultivar/variety name in quotes, then the scientific name (genera and species) in italics.
For a thorough rundown on plant terminology, click here to read more about plant nomenclature.
Native cultivars (aka 'Nativars') are all derived from native species - they have simply undergone some level of selection. This varies from basic selection (finding a unique variant in the wild and propagating it) to further selection within a breeding program (for enhanced disease resistance, improved growth habit, different bloom colors, etc.), but all nativars still maintain the same scientific classification as the straight species. It is important to remember that when you purchase a nativar or a hybrid, the seed will not be true to the parent - a native straight species may self-sow in your yard, but your nativar will not propagate naturally (you may have babies pop up nearby, but they will likely have reverted to be closer to the parent straight species).
So, are nativars less beneficial for the environment than straight species?
Nativars that have undergone extensive selection are not harmful - they just may not be as beneficial to wildlife as the straight species (the same goes for most hybrids). It is important to consider that straight species natives are directly contributing to biodiversity and are typically preferred and more accessible food for wildlife. Most cultivars have been selected primarily for ornamental traits, and if bred extensively to enhance these traits, some of their ecological benefits may be compromised in comparison to the straight species. Many nativars that have been significantly manipulated were found to be less attractive to pollinators (see Dr. Annie White’s research). Tom Tribble of the Blue Ridge Audubon shared with us that many non-natives and hybrids are often providing significantly less protein content in their nuts and berries to our local birds (we will delve more into non-natives vs natives and how they affect our local bird populations in a future blog!).
A prime example of a highly altered nativars are varieties of double bloomed blanket flower with tubular petals such as ‘Fanfare’ or 'Double Sunset' - very interesting to look at, but it makes the nectar much harder to access. The many vibrant orange and red shades of newer coneflower cultivars and hybrids are often not as appealing to bees as the native straight species alternatives (they prefer violet tones and therefore the purple of Echinacea purpurea or tennesseensis). And the darker-leafed nativars of Ninebark species are less likely to be eaten than the green-leafed straight species (which may mean you have more tidy looking shrubs, but also means you are providing less food for insects that typically depend on it).
However there are many less altered nativars that are still very beneficial and equally desirable to pollinators. The many studies being done in this area seem to show that every cultivar needs to be considered on a case by case basis - some are actually shown to be equally beneficial, while many others have decreased appeal or benefits to pollinators or birds. Dr. Tallamy’s research has shown some cultivars such as Agastache 'Golden Jubilee' to be more beneficial than some other straight species Agastache (though less appealing to pollinators than its native parent Agastache foeniculum.) He also found that pollinators were attracted to ‘Hello Yellow’ Butterfly Weed just as much as its bright orange straight species parent Asclepias tuberosa. And 'Black Truffle' Lobelia cardinalis showed equal support of pollinators when compared with its straight species parent, the green-leafed cardinal flower. Another researcher, Keith Nevison found that the garden phlox nativar ‘Jeana’ actually attracts far more pollinators than the straight species parent Phlox paniculata.
In general, it seems the key to maintaining pollinator friendly nativars is minimal manipulation, with the understanding that it completely depends on the type of plant as to what alterations may decrease wildlife appeal/support. At Painters, we try to carry minimal cultivars with heavier modification - most are very close to their natural-found counterparts. We plan to make a list of nativars that have demonstrated relatively equal (if not better) pollinator/wildlife benefits, and hope to grow as many as we can here at Painters in addition to the wide selection of straight species options that we offer.
For those of you looking to restore and preserve native habitat and wildlife with your plantings (especially if you’re doing a large-scale pollinator/wildlife garden), the more straight species natives you plant, the better. If you’re working with smaller spaces or specific garden designs, more nativars and hybrids may be better suited, but we encourage you to try a few straight species to balance out those that may be less beneficial. Note that many annuals and herbs are also great pollen and nectar sources for pollinators and birds, so don’t be afraid to incorporate beneficial and beautiful annuals such as zinnias, cosmos, sunflowers, Mexican Sunflower, borage and basil if you're gardening with pollinators in mind! Finally, it is important to note that planting a native tree is the best possible thing you can do to support pollinators - we tend to think about pollen and nectar sources for adults but often overlook the necessity of host plants that feed the larvae. Native oaks, cherries and willows are excellent options - feeding up to 532 species of caterpillars! This is also incredibly important for bird diversity as they rely on those caterpillars to feed their young! (Check out one of our favorite native plant enthusiasts on Instagram as he talks about the importance of oak trees and other native species!)
Keep in mind that while we try to grow a wide selection of natives and nativars, including a variety of straight species options, it is you, the customer, that drives the market. Many straight species can become tall, floppy or just not be flowering at the time of purchase and therefore typically don’t market nearly as well as cultivars. Want to see Painters and other garden centers grow/sell more straight species plants? Then please request them and purchase them instead of their cultivars or more showy hybrids so we can continue to expand our straight species native selection!