Doug Tallamy Is Not Always Right

Camphor Tree in my front yard

Black Swallowtail caterpillar feeding  on curled parsley

Dr. Tallamy has done a great service to those of us that wish to create more life in our landscapes. His book, Bringing Nature Home, has served as a guidepost to a great many and is frequently cited for his early chapters that extol the virtues of native plants and the detriment caused by the all-too-common traditional landscapes of non-native ones. As my ex-wife, Alexa, used to tell me - he keeps the message simple and that is the most effective way to communicate what I've been trying to say for well over 30 years now. The only problem with simplicity is that it is often too simple. It is too often too easy to take the simple message and embrace the whole thing without digging a bit deeper beneath the surface. Life is not simple and it is not comprised of simple messages.
The message that native plants are good for wildlife and that non-native ones are responsible for the huge declines in wildlife diversity in our developed landscapes is just too simple. We want to accept it, but it is disingenuous. That may sound sacrilegious to many who read my writings, but it is true. I have been a major proponent of native plants and native plant landscapes for decades, but I have done so not because they are native, but because they are often the best plants to create living landscapes. My overriding goal these past 30+ years and the reason for all my writing and public speaking, is to encourage the creation of landscapes that promote life. Sometimes that life can be generated with non-native plants. That is not to say that there aren't native substitutes, but too often those substitutes are just not available, they are not well-adapted to a site, or they are not practical.
Today, I learned yet another lesson regarding this. For the past few weeks, I've watched spicebush swallowtails flitting through my backyard. They have not stopped to nectar on any of my wildflowers and it has intrigued me as to why they are present. Butterflies don't just show up and flit about unless there is an underlying reason. This morning as I sat on my front porch enjoying my coffee, my curiosity was satisfied; spicebush swallowtails were in the canopy of my camphor tree laying eggs. When I moved in to my new home, I also adopted the single shade tree in my new landscape - a mature camphor tree. As a Class 1 invasive exotic, my instincts were to hate it. As a renter, I have not felt the right to cut it down, so I limbed it up to reduce the breadth of shade it generated and planted my wildflower garden as far away from it as possible. Today, I discovered something that I had not known before - that my camphor tree serves as a host plant to a beautiful butterfly that I have not yet been able to provide for with native plants. I have planted a native bay tree, but it is too small to attract the attention of the swallowtails. It may be a decade before it is tall enough. My invasive tree (which I would still dearly love to kill) is serving an important function in my quest to create a living landscape here.
It is not true that our native pollinators shun every non-native plant or that butterflies and moths will not lay eggs on them, thereby generating caterpillars for birds. The message is too simple. If we are to create living landscapes, we need to understand the roles of the plants we landscape with. There are a great many native plants that have extremely limited value and non-natives that serve an important function. It behooves us to truly understand our plants as well as our site conditions if we are to maximize our success. Of course, that requires us to dig a little deeper beneath the simple messages we are confronted with.
My eastern black swallowtails are here right now only because of my non-native curled parsley (they shun the flat leaf variety). The native water dropwort (Tiedemannia filiformis) will not bloom for another month and I have never seen the butterflies use it until it blooms. My giant swallowtails are here only because of my key lime. There is a native plumbago (Plumbago zeylanica), but it is a rambling plant that will never win an award for its landscape potential. The non-native blue plumbago (P. auriculata), however, is a showy species and both serve equally well as the host plant for the Cassius blue butterfly. I see them sometimes in my landscape and it is only because one of my neighbors has planted one. There are non-native passionvines that make excellent host plants for our passionvine butterlies and some that are useless. Common non-native lawn weeds like black medic (Medicago sativa) serve as host plants to some of our butterflies. Even our much maligned turf grasses are important to various of the grass skippers. I would never have raised a gold rim swallowtail in my former yard without the non-native pipevines I had planted. None of the native species perform in my region of Florida like they do north of me and the diminutive Aristolochia serpentaria is not propagated. Even if it was, I would need dozens to get a single caterpillar to maturity.
I am not promoting non-native plants, but I do not decry their use either. We are never going to "restore" our typical suburban yards to a fully functional ecosystem. If you have acres to work with, perhaps you can, but most of us are working with 1/4-acre yards. In these conditions, we need to maximize the ecological value of what we have and that requires us to choose our landscape plantings for their ecological role and their ability to foster life. Sometimes, that means using a plant that is not native and weeding out a few that are. What all this REALLY means is that you can't spray your plants with pesticides. When all is said and done, that is the real message of Dr. Tallamy and myself.

Sphinx moth caterpillar on my "Everglades" tomato. A non-native plant and a beautiful native moth