In addition to growing straight native perennials, shrubs, and trees, we also offer “nativars” – native plants selected for their smaller size or other small urban garden-appropriate habit while maintaining their environmental value and low-maintenance local adaptability. Our feeling is that it’s better to grow a native plant that has been selected and grown as a genetically identical clone of the parent to fit smaller-sized space or lower height for traffic visibility when necessary than to grow an entirely non-native plant.
In a Fine Gardening article titled “Are Nativars OK?” by Keith Nevison, the author speaks to observations that show there is variety in preference by pollinators as a result of such things as selections that are more floriferous than the species providing more nectar opportunity. In some cases the straight species is better, but might not be possible to grow due to size, for example, making the choice of a less useful native selection better than a non-native choice.
Keep the following information from the article in mind when selecting plants:
Physical changes in flower anatomy may restrict access to pollen and/or nectar for feeding.
A wider corolla may increase dilution of nectar; a smaller corolla may concentrate nectar-enhancing rewards for pollinators.
Different colors may alter cues associated with pollinator attraction.
Pollinators may prefer feeding higher or lower as a means of protection from predators.
This is probably benign for pollinators but not for insects who might feed on the foliage.
Many cultivars bloom earlier/later/longer. This can be good, or it can mess with the timing of when the pollinators need that plant. One of the biggest values of native cultivars is that they potentially extend the window of nectar/pollen benefits to wildlife.
This is unknown. It could be that some pollinators preferentially feed closer to the ground to avoid detection by birds and other predators. The opposite could be true too (e.g., Phlox ‘Jeana’ is supertall, and lots of pollinators feed on it). More study is needed on this topic to confirm.
Citizen science like the Nativars Research Project is one way data is being collected on the question of how best to support pollinators in our urban gardens. Click the link to learn more about how you can contribute!