Weeds and the Butterfly Garden

About ten years ago, my family and I moved into a new house.  On the property were orange trees and patches of rue, an odoriferous herb used in some cultures as a culinary herb (in minuscule quantities), and as a good luck charm in others.  The orange trees gave us delicious Valencia oranges, and the rue, attractive, small yellow flowers in the early spring, but they also brought us another gift: swarms of giant swallowtail and black swallowtail butterflies.  We added a lime tree and parsley, and discovered that the giant swallowtails were also fond of lime trees, and the black swallowtails, of the parsley as well as the rue.  The abundance of these butterflies, along with the other lepidopteran visitors to the lantana flowers that grew everywhere around our new house, led me to an interest in butterflies in general, and specifically, in those who shared our home.

      As I learned a little about butterflies and their habits, I came across instructions for creating a “butterfly garden.”  We were already surrounded by butterfly-friendly plants, and I added others that butterfly gardeners recommended.  Soon pentas, butterfly milkweed, vitex (chaste tree), buddleias (butterfly bush), and verbena joined the lantanas, mint and sunflowers.  To make room for them, I cleared out “weeds” like wild purslane, clovers brought by birds, globe mallow, and wild grasses.   I added “sunning rocks” and a water source for the butterflies.  All of the butterfly garden instructions that I found online emphasized the importance of planting flowers that were good butterfly attractors; essentially abundant, accessible sources of nectar for adult butterflies.  I used guidebooks and sites like www.butterfliesandmoths.org to learn to identify a wide variety of butterfly visitors.

     In the course of learning to identify various butterflies by sight, I also began to learn about their life cycles.  The led me to the realization that a truly thriving butterfly garden meant more than just having lots of flowers for the adult butterflies.  Hadn’t I first noticed the butterflies because of the abundance of food in our yard for the larvae of the giant swallowtails and black swallowtails?  I slowly realized that my butterfly garden needed not only food for the adult butterflies, but also plants for them to lay eggs on that could serve as food for their larvae.  I learned what host plants our butterfly neighbors needed in the larval stage, and whether or not they were available locally.  The first step was to see if they existed in our garden.  Then I walked the immediate neighborhood to see if they grew in other yards. 

      On occasion, I would see a gulf fritillary on the lantanas in our yard, and I learned that their larvae subsist solely on members of the passion vine family.  I was happy to find that several of our neighbors had stands of passion vines growing in their yards.  (I would also like to plant passion vines someday, if I can just find the right spot.)   I also realized that many of the plants the butterfly larvae in our area needed for food—which were considered “weeds” but thrived in alleys, along roadsides, and in vacant lots—were regularly being eradicated by the city through the massive spraying of herbicides.  And I also learned that many of the plants I had eliminated from the garden as “weeds” were, in fact, important host plants for butterfly larvae.  Wild purslane, for example, is a crucial host for the larvae of our abundant variegated fritillaries, who typically depend on violets in other biomes.  Where I live, the hot climate and alkaline soil and water make it almost impossible to cultivate violets outdoors.  The lack of violets means that the variegated fritillary larvae in our area have come to depend almost exclusively on wild purslane.  Needless to say, I quickly reintroduced wild purslane into the garden.  (Wild purslane, Portulaca oleracea, is also a delicious, highly nutritious salad herb.)  Globe mallow, a favorite of grey hairstreak and painted lady larvae, was also welcomed back.  (Again, it is a useful herb as well; its roots have many medicinal applications, and its flowers make a delicious tea.  It’s a little hard to harvest, as its leaves shed tiny, irritating hairs, but it is also delightful simply as an ornamental.)

      All of this has led me to suggest to people who are interested in creating a butterfly garden to follow four simple steps to insure success:

  

1.      Familiarize yourself with the butterflies that live in your area and learn to identify them.  There are good guidebooks for this, and the internet is also a great resource.  At www.butterfliesandmoths.org you can search for the specific butterflies found in your state and county.  Remember that butterfly databases are based on verified sightings within a given area, so you may occasionally see a species that is not in a database for your region.  This means that you may have to do a little extra research to identify it.  But databases are generally a good starting point.

 2.      After you have learned what butterflies live in your area, learn what plants the adults and larvae use for food, and how to identify those plants.  Take a walking tour of your neighborhood and see if those plants exist in other people’s gardens or in the wild.

 3.      If good butterfly host plants are not commonly found in the area, and if you would like to give your local butterflies a helping hand, consider planting them in your own garden.  Of course, you will need to make sure that the plants you choose are suited to your region.  If you regularly experience hard frosts, you don’t want to try cultivating orange trees, for example.  Hardier rue is a better choice.  Oranges and rue belong to the same family, and rue is an attractive host for giant swallowtail, anise swallowtail, and black swallowtail larvae.

 4.      Finally, before you pull out weeds, learn a little about them.  Many plants considered “weeds” are actually beautiful ornamentals, valuable medicinal or culinary herbs, and essential butterfly larvae hosts.  In many places, Virginia snakeroot is considered to be a nuisance, to give one example, but it is also a useful medicinal herb in experienced hands, an attractive ornamental, and an important host for the pipevine swallowtail.  If you are worried about the “weeds” spreading and taking over, cultivate them in pots.

      Following these simple steps will help to create a complete habitat for your butterfly neighbors and accommodate them during their entire life cycle.  In this way, you will not simply have a butterfly garden, but a true butterfly environment.