Cardinals and jays frolic in the rear garden. Here, there is a substantial cover of deciduous trees and tall evergreens, some from the native forest and others planted by the gardener over twenty-three years. Mossy boulders nestled beside the rills of garden ponds (above) provide still water easily accessed for a drink or bathing. And, there are abundant berries and fruits (Leatherleaf mahonia, below) to be harvested from nearby shrubs, some native to these foothills of northwestern Virginia, some not. The ravenous birds care little. 
The Alaskan cedar (Chamaecyparis nootkatensis) outside the kitchen window provides a tall perch for birds, and particularly squirrels, who scramble through its branches and then leap to the wide spreading limbs of the neighboring ‘Burgundy Lace’ Japanese maple (Acer palmatum ‘Burgundy Lace’, below). From the maple it is only a short bound onto the library roof, and from there (through some hidden entrance) into the attic. This is a constant source of consternation to the gardener, and particularly an aggravation to his wife (who declares that the squirrels must go, even if murder is required).
I am only mildly annoyed by authors who suggest this environment is possible when native plants alone are utilized. No science is required to know that the grape-like fruits of mahonia are stripped bare soon after ripening. Native American dogwood or Oriental mahonia, it matters not, berries are consumed quickly. There are, of course, plentiful native plants in the garden, so that butterflies swarm to the native butterfly weeds (Asclepias tuberosa), but also exotic butterfly bush (Buddleia, below), and if they know or care about the difference they’re not telling.
Non-natives require more water, pesticides and chemical fertilizers, some say, but in this wildlife garden plants make do without. The lush habitat testifies that chemicals and supplemental irrigation are not demanded by natives or exotics located properly, though both might be nibbled by caterpillars or invading beetles. Deer have preferences that are not dictated by the geographic origins of a plant, and a a mildly malodorous organic repellent is required to persuade them to feed elsewhere.
Invasive plants are avoided in this garden, but rambunctiousness is encouraged, and barely restrained plants scramble over and through neighbors. It seems obvious to the long time gardener that most non-native plants do not seed or spread themselves about uncontrollably, and are no more or less thuggish than indigenous plants. Native plants are no more well suited to the managed environment of the garden than exotics, and this garden would seem incomplete without Japanese maples and camellias, magnolias, and azaleas. This matter of natives, non-natives, and invasives has been politicized and so much chatter is hyperbole (nearly in the manner of presidential elections) that it seems to discourage planting rather than encouraging its benefits, native or not.
Ramblin' through Dave's Garden 
Would not the problem with the butterfly bush lie in its very attractiveness, creating a false sense of complacency in the gardener? Is it like thinking that a hummingbird feeder could somehow substitute for real habitat? If butterflies are unable to reproduce because we have crowded out the larval host plants, then feeding the adults may not be particularly helpful. Although not everyone may be ready to devote their property to habitat restoration, the least we might all do is avoid the use of plants which are the invasive species lists for Virginia. Like the butterfly bush.
I agree that gardeners should not be fooled. A flower that attracts pollinators is not beneficial if it proves to be invasive. I have seen buddleia seedlings growing in highly disturbed, bare soils, but have not seen them growing with competition in meadows or grassy areas to demonstrate to me that they are clearly a threat to displace natives. But, there is ample evidence of their potential for invasiveness that I’ve opted for hybrid varieties that are sterile, or have extremely low germination rates.
In nearby meadows I’ve witnessed ornamental grasses (Miscanthus gracillimus and Pennisetum alopecuroides ‘Moudry’) growing vigorously and spreading, and along farmland fence rows in the area flowering pear seedlings grow rampant. These are clearly displacing natives.
Each year many dozens of Japanese maple seedlings sprout in my garden, but I have not seen one growing outside the garden’s boundaries, in the forest, or in the meadow beyond. Yet Japanese maples are listed as an invasive in Virginia, despite a lack of evidence so far as I can see. For this, I am skeptical that lists of invasives are evidence based, and I fear an overwhelming influence by adherents of planting native plants only.
Yes, there does not seem to be any standard for those lists. Perhaps what we need is for representatives of the nursery industry to get together with foresters and other naturalists and figure out what really makes sense. If the nurseries feel adequately represented in the process, they might then be inspired to stop selling those plants that are truly problematic. Has anyone ever tried to start a conversation like that, do you know? I am guessing that the profits of the nurseries would be unaffected . Since I started trying to avoid certain plants and use more natives, I have spent a whole lot more money in nurseries than I ever did before!
Margaret
I believe that on the state level nursery representatives are usually invited to be a part of the process when lists of native plants are being developed. For invasive plant lists, I’m not so sure, but I once spoke at length with a long time nurseryman on Long Island who had been part of their local government compiling a list, and he was extremely frustrated with the lack of attention that was given to his point of view, both as a professional and as a long time gardener.
I’m quite certain that nurseries would be more willing to pay attention to invasive plant lists if they were convinced that the plants were included due to reasonable evidence. Now, I don’t think this is the way that regional lists are compiled.
Unfortunately, as it turns out, while non-native trees and shrubs may provide seeds, nuts, or fruit for birds and other wildlife, or nectar for pollinators, they do not support birds during their most crucial period – the nesting season. Many, perhaps most, species of native birds feed their young primarily on insects. Caterpillars in particular are one of the most important groups of insects collected by birds to feed to their offspring. Non-native plants support fewer species of insects, and many support no caterpillars at all. In recent studies of the foraging habits of nesting birds, non-native trees were avoided, even when they were most convenient. Birds foraged further afield, in native trees – where all the food is.
We’ve done irreparable damage to the ecosystems around us. This one small thing is a way to repair just a bit of the harm, and help to boost dwindling songbird populations. Plant natives, instead of non-natives. There are so many attractive native species you can choose – people rarely look beyond what’s available in typical garden centers.
There’s irony in your use of the image of a tiger swallowtail on that butterfly bush. These butterflies require native tulip trees, magnolia, black cherry, or wafer ash (the list goes on) to support their larvae. There are a select few non-native relatives of their host plants that the butterflies can use, but the butterfly bush itself is not one of them. Many butterflies and moths feed only on native plants.
The list of butterfly larvae that feed on native passionflower (maypop) is amazing. If you truly want to draw birds and butterflies to your garden, natives are superior in every way.
Ironically, the trait of ‘pest resistance’ in non-natives is the very trait that makes them such a wasteland in the local ecosystem. Native plants are naturally resistant to the ‘pests’ (bird food) that live around them, without being barren of them entirely.
In regards to pollinators, our imperiled bees are at the top of the list of insects that suffer from non-native plantings. Contrary to what most people believe, bees do not simply utilize any flower they come across. The domesticated honeybee may, but our native bees can be remarkably picky. And they do not like non-native flowers. If you plant non-native nectar flowers, you may draw three or four species of bees. If you plant natives in a good variety, you are may draw more like a dozen species.
There is no reason to be an apologist for using non-natives in your landscape. They are inferior to natives when it comes to supporting wildlife. Do what makes you happy, but don’t kid yourself (or others) about the impact of it.