Should it stay or should it go?
|Eastern Tiger Swallowtail|
In researching this claim I found that Buddleja, a native to Asia, is highly invasive producing thousands of seeds during the growing season. I have never had Buddleja reseed in my garden, have you? During the summer when the mood strikes me (which is hardly ever!) I may deadhead the shrub but frankly it is a very time consuming and not a very fulfilling activity (especially in the heat). Since they bloom on new growth I severely cut back my plants each winter/early spring to ensure more blooms during the season . However, I can honestly say I have never seen them naturalize in Georgia.
But according to the USDA Forest Service they are invasive in my region. You can view the map here to see all the states where Buddleja is listed as invasive.
According to Doug Tallamy, PhD, chair of the department of entomology and wildlife ecology at the University of Delaware in Newark "nature never meant for these bushes to be here, so the plants aren't equipped to feed the beneficial bugs and birds in our region of the world. This disrupts the entire food web."
|Easter Tiger Swallowtail|
Exotic, invasive plants harm the environment by competing with native plants and eventually crowding them out. Native plants are important because they provide food for native bugs, birds and other animals which have evolved together. Tallamy says the "30 percent of plants in most natural areas are invasive" which in turn reduces the food supply for birds and insects.
I am very passionate about native plants and am adding more and more to my garden each season; however, I do have many non-native plants too. The Native Plant groups and Master Gardener organization that I belong to define natives as plants that were here before the European settlers arrived. Kevin Songer wrote a thought provoking piece More Spirits In Plants Than In The Heavens, Native or Not at Native Plants & Wildlife Gardens. He proposes a lot of questions about what makes a plant native. Check it out and see what you think.
|Great Spangled Fritllary & Eastern Tiger Swallowtail|
Genevieve at North Coast Gardening recently blogged "things in our garden are either making a positive difference in the world (to us or wildlife), or they are taking up space that could have been used for something better."
In this case, while the butterfly bush is an attractive nectar source for pollinators it is not a host plant for any butterfly or moth species. Butterflies and moths therefore have to use energy and time to find another source to lay their eggs.
|Clearwing Moth (aka Hummingbird Moth)|
In response to this ban on butterfly bushes several nurseries are developing new butterfly bush varieties with a very low fertility rate.
So what does a responsible wildlife gardener do? Do I deadhead every bloom and never let it go to seed to ensure that it doesn't naturalize (although I have never seen it reseed here)? Or do I dig up all my shrubs and replace them with a native alternative?
So what say you readers? Will you (or would you) pull out your butterfly bush(es) if they are invasive in your area or can you not part them?
Final note: all the photos in this post were taken on the butterfly bushes in my garden to demonstrate the variety of pollinators it attracts. However, this is by no means all the butterflies in my garden nor is it the only nectar source available.