Navitars or Natives? I can tell you a formal garden is many times better off using Navitars if they are better behaved garden partners. How do you know what you are buying though?
I see nursery displays advertising native plants and when you look closely, many times they are only the native cultivars. Do the Navitars provide the same benefit to wildlife as the true native? I think it best to observe the plants and see if the native cultivars attract pollinators to the same degree as their original counterparts before heralding them as so. It is best to have an understanding of how far removed the plant is from the original too.
I always mention on this blog how these “native plants” are many times named selections of native plants bred for their unique adaptation of bigger blooms, bolder colors and longer period of bloom. They are cultivars. And because of the breeding, the plants are changed in some beneficial way for use in home gardens.
Some of these plants may have come about by lucky wind – driven accident or mutation which is very close to the original, but others are cultivated by long time selective breeding.
Plants are selected to be superior in some way to the original. That is a great advantage to the gardener, but not necessarily a benefit to the pollinator. Oft times, they are better garden plants because they stay put or co-exist better with neighboring plants.
The problem with some of the cultivars is breeders change flower shape or effect sucrose levels. These two changes may eliminate or reduce the native pollinators with changes that impact the pollinators which have evolved to obtain nectar and pollen from their wild counterparts. The link is to a very well done study.
Studies suggest that few cultivars have enhanced nectar value and attraction for native pollinators. It may not be far worse, but usually it is not found to be better. Studies can show some Navitars to be a good resource for wildlife because of a longer bloom cycle through the season. In these cases, the Navitar does have a great benefit to foraging insects.
In my own garden above, I have tested some of these plants to eliminate or reduce certain showings that have little benefit. I found certain phlox to be not more than merely ornamental, like the Flame Series or Blue Paradise in my garden above. The back garden has David and a few other varieties. David attracts pollinators where others are just showy.
So whether one chooses to have the better-behaved Navitars or the strict native variety may depend on the size garden in which they inhabit. Many of my native plants are indeed Navitars for the simple reason the native species is too aggressive for small-space gardening.
I visited a very beautiful and nicely planned formal native garden, Mt Cuba Native Gardens, while in Delaware recently. As I took the tour with a docent, I questioned the use of named cultivars. The docent would not admit them being cultivars, yet in the formal area of the native gardens, many, many named and signed cultivars were present. Many were the same plants in my own garden and I am certain they were installed for the same reasons. Better control of the plants.
The formal gardens shown in this post are beautifully done with natives and cultivated natives. Mt. Cuba ran test gardens for various native cultivars, one of which was phlox. I wonder if they too found some to be unattractive to pollinators as I did.
It really is hard to visually access and judge what is attractive to insects but extensive studies have been done. Navitars do have a place in gardens trying to attract and benefit wildlife. I find pollinators gravitate to a garden filled with bloom rather than a drought stricken meadow devoid of bloom. So even if a Navitar provides less nectar or pollen, it certainly beats a meadow that is dry and brown.
Do you find this garden attractive? I do regardless of whether they strictly use true natives or not. If I had more space, I too would use that native purple cone flower.