Nativars = Native Plant Cultivars
Finally, the weekend has
arrived! It's Saturday
morning and you rush to your local garden center to buy plants for your front yard natural area. You heard butterfly weed,
Asclepias tuberosa, is good for bees and butterflies but the local nursery only has
Asclepias tuberosa 'Hello Yellow.' That's what I am looking for, right? Well, the often catchy name behind the genus and species (Latin names) is the "cultivar" trade name. Also, plants simply labeled with its genus, like Echinacea, without a species name like
purpurea, is an indication that it is probably a cultivar.
Cultivars are genetically different from true natives, being bred for certain desirable attributes, such as flower color, stature, or bloom period. These super plants are commonly propagated by divisions, cutting, or grafting, and are not typically grown from seeds. "Nativar" is a catchy term used to identify a native plant cultivar.
It's just human nature to dream about improving the plants around us. It is thought that the practice of creating cultivars first started between 9,000 and 11,000 years ago! To make our Minnesota natural shores a bit tidier; wouldn't it be great to have a 3 foot tall New England aster? Maybe sometimes you wish that your native iris had a white flower? Or perhaps, it would be fun to have a carpet of 2 foot tall prairie cord grass?
We often get asked questions about natives versus nativars. Our clients want to know if they have a place in our restorations. Are there ecological consequences if we choose to use nativars? This is a pretty complicated question, and research is now underway to better understand their environmental implications. Below is some basic information to help you make informed choices.
First off, the production of nativars is not natural; it is controlled by horticulturists and plant breeders. They often use a technique called vegetative propagation so that certain characteristics are guaranteed to be present in the new plant variety. On the flip side, native plants in the wild experience "open pollination" meaning that genetic material can be mixed by pollinators visiting a multitude of plants.
Open Pollination of Butterfly Milkweed
So with nativars, it is in their development that they lose some of their genetic variation. As a result, plants with less genetic diversity are being placed into the landscape. Sometimes, this has positive effects in that a plant cultivar might be more resistant to some diseases. But in other ways this can have negative consequences. More genetic diversity usually means plant populations are more resilient to disturbances like pests, diseases, or even climate change. When nativars are put into an ecosystem instead of natives, generally, that ecosystem has less ability to adapt to future stressors.
Research has suggested that bees and other pollinators might not be attracted to the nativars in the same way as native plants. This is because native pollinators have
evolved alongside native plants, with the plants developing specific traits to attract the insects that pollinate them. Traits like flower color, bloom size, bloom shape, plant height, fragrance, and petal patterns. Changing characteristics in native plants can confuse wildlife. For example, some nativars have been bred to have more flower petals, called double-petaled, which make it impossible for the pollinators to access the pollen and nectar. Some cultivars are sterile and do not produce seed, whereas, natives create seed which provides food for a multitude of animal species.
OK, so say you kick the nativars to the curb and choose to go with a nice diversity of natives. In a couple of years, you have a situation where a few species are just too aggressive or get too tall. Go ahead and try to tame the plant a bit. Go ahead and trim it in June. This works great for a multitude of species like Joe Pye weed and New England Aster. The plants will still flower and just be a bit shorter when they do bloom. Do you like how some cultivars stay in perfect clumps? It takes more energy and maintenance but you can always cut back or thin the sprouting rhizomes of your native plants and add mulch to keep a more formal look.
Joe Pye weed flowering after being cut shorter in June
Need help choosing a native plant for your garden or restoration? Visit our retail nursery for help!