What Are Nativars and Are They Good or Bad?

A cultivar of a native plant species is often referred to as a "nativar".

Nativars are the result of native plants that have been selected or altered through breeding to have features that humans often desire - like bigger blooms, brighter colours or disease resistance. Some hybrids are sterile and therefore may not produce any pollen.

As a very popular example, the native purple coneflower has been highly cultivated and here are some of its "nativars" (the picture on the left showing the straight native, Echinacea purpurea):

Echinacea purpurea is the straight native species of purple coneflower

Cultivars of Echinacea purpurea. From left to right: one of many yellow cultivars, 'Green Twister' cultivar, one of many red cultivars and 'Pink Delight, double bloom cultivar.

In some cultivars, like the 'Pink Delight' double bloom pictured above, the pollen and nectar, even if limited, may be difficult to access due to the altered flower shape. As for cultivars that have been bred to have altered colours, we need to be highly skeptical of their ecological value: it's thought that those alterations might have a negative impact on pollen and nectar production. All of this causes pollinators to have to make a greater effort for a lesser reward.

Another aspect that makes a great many nativar inferior to straight natives ecologically, is that most of these cultivars are propagated clonally through tissue cultures or cuttings, which means they show very little genetic variability. In this age of climate change, genetic diversity in our plants is becoming increasingly important. With extreme climactic swings like we're experiencing and which are becoming more frequent, allowing plants with low genetic variability out in the ecosystem is not the best idea. We need to ensure strong genetic diversity so that plants can adapt to change.

As Kim Eierman states: "Keep in mind that while straight species native plants will provide the greatest genetic diversity in a landscape, cultivars can be very useful when size, disease susceptibility, and plant availability, among other issues, may be a concern".

SIZE MATTERS

Some nativars are shorter or more compact than their native parent. Those are often developed from a genetic variant found in the wild to be smaller than others of the same species. Those smaller native plants are selected, given a name, bred to have the same genetic trait as their parent and sold as a cultivar - or a "nativar".

In essence, size is a functional trait that enhances our ability to use a plant in a residential landscape. A great example would be the cultivars of Joe Pye Weed.

Eutrochium maculatum (Spotted Joe Pye weed)

'Little Joe' (height 120 cm or 4') and 'Baby Joe' (height 60-90 cm or 2-3') are shorter cultivars of the native coastal species of Joe Pye weed - Eutrochium dubium, which usually grows to about 170 cm (5.5'). 'Phantom' (height 60-90 cm) is a much shorter cultivar of the giant Eutrochium maculatum, which can reach towering heights of up to 2 meters (over 6' tall).

 If being smaller allows you to use a high-value plant in your landscape, go for it, there's nothing wrong with that! It might just be better to use a cultivar of a native plant than an alien ornamental.

LEAF COLOUR

From top, left to right: Penstemon digitalis and its cultivar 'Husker Red'; bottom, left to right: Physocarpus opulifolius and its cultivar 'Coppertina'

Another aspect to be weary of is leaf colour. Plants that have been bred to have purple leaves or dark foliage for example (like the many cultivars of Physocarpus opulifolius, the Common ninebark, and Penstemon digitalis, Foxglove beardtongue pictured here on the right), may not be nutritious for insects. Or, because of the anthocyanins that give the leaves their red or purple colours, insects might not even recognize them as a food source.

The main problem we need to address is that we've been trained to think of plants as just decorations.

Cultivars are beautiful, and we DO want beautiful plants in our garden.

But we need to start putting more value on those vital functions that plants are performing within their respective ecosystems.

Like Professor Douglas A. Tallamy has aptly stated, “it’s not the presence of cultivars, but the absence of natives that’s a problem.”