What Plants Do I Need In My Garden For The Two Tailed Swallowtail In Arizona

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Turning Dirt into Butterflies:
Butterfly Gardening in the Southwest

by Jim Brock
Tucson, Arizona

My butterfly garden started in 1991 when I bought my first condominium. During the previous 14 years that I had lived in Tucson I had never had any yard space. This condo had a small L-shaped area of about 800 square feet. There were no plants or shrubs when I moved in, and the previous owners' dogs had created a desert of dirt. However, there were three mature trees: two sweet acacia and an exotic species of palo verde.

I began by removing the palo verde. I kept the two acacias for shade, one on the west side and the other in the northeast corner. Keep in mind that the yard is so small that the trees shade not only the edge of the house but outside of the yard as well. Sweet acacias are messy, spiny trees, and I would not recommend these for the butterfly garden. Next, I repaired what the dogs had left of the drip line. This means that I replaced everything but the original timer, which, after twelve years, is still ticking!

Nectar Plants
The first nectar plant to go in was kidneywood (Eysenhardtia orthocarpa ), a fragrant native to the area. This plant has proven to be a good one -- not only for butterflies, but for native bees and wasps as well. I also put in five bee bushes (Aloysia gratissima ). Bee bush is another fragrant native that attracts small butterflies. Well, there went one-fifth of my space! Now, for medium- and large-sized butterflies, non-native lantanas are the answer. In the southwest, trailing lantana (Lantana montividensis ) is a superb plant! The purple flowers of this ground cover plant are extremely attractive in any garden, and they really bring in the butterflies. More importantly, the plant often blooms during the winter months when most other nectar plants are dormant, so it provides a reliable source of nectar. I started with five of these spaced about ten feet apart. I added one of the shrub lantanas (Lantana camara ). On the north side of the yard in the sunniest location I added one red bird of paradise (Caesalpinia pulcherrima ). This gorgeous plant blooms all summer and lures swallowtails and an occasional skipper. Given full sun and the right amount of water, this plant can reach seven feet. My original is nearly outgrowing the yard after five years. In the past two years I have experimented with lagascea (Lagascea decipiens ). This yellow-flowered native looks similar to lantana and shows great promise for southwestern gardens. It seems to require less water than the lantanas. One other exotic nectar plant worth mentioning is butterfly mist (Ageratum corymbosum ). Though it is a moderate water user (this means daily watering in the southwest), it is a magnet for Queens and other butterflies. It is one of my most recommended plants in the Tucson area. A great plant!

Jim's Garden

I also wanted one of the best late summer nectar sources, so I added one seep willow (Baccharis glutinosa ). I would have put in ten or more of these, but there was no room. Just outside of the yard was a close relative of the seep willow, desert broom (B. sarothroides ). To most folks, this plant is an unwanted weed, but during its October bloom it is a prime nectar source for the Great Purple Hairstreak.

Caterpillar Food Plants
The most enjoyable aspect of butterfly gardening is discovering caterpillar food plants. The caterpillar food plants for many butterflies in the deserts of the Southwest remain to be discovered. Hence, I am always trying different plants even for some of the more common butterflies. In five years my butterfly garden has provided me with more than a few surprises. It's still fun, however, to use the basic plants such as passion vine and senna (Senna leptocarpa or S. lindheimeriana ). In fact, senna has proven to be a backyard food plant for no less than four butterfly species (Cloudless Sulphur, Sleepy Orange, Boisduval's Yellow, and the Gray Hairstreak).

In addition to senna and passion vine, no garden would be complete without some type of milkweed. I have tried pine-leaf (Asclepias linaria ), narrowleaf (A. subulata ), and butterfly weed (A. tuberosa ). The results have been mixed for unknown reasons. If I had more space I would try more varieties. Fern acacia is another good food plant to use. The Acacia Skipper will find it no matter where you live. The caterpillars, like those of most skippers, make a nest or shelter of the leaves of the plant. With careful, patient observation these are easy to find. The Mexican Yellow also uses this plant, though it was four years before I found any caterpillars.

As I stated earlier, I did not have much planting space. However, I decided to use the former location of the palo verde tree for our native ash tree (Fraxinus velutina ). I hoped to capture the attention of a wandering female Two-tailed Swallowtail from nearby Sabino Creek. In two different years I have found the caterpillars, though I've only seen adults on four occasions.

Two plants I did not want to use are bermuda grass and citrus. Both are common throughout Tucson, so it isn't necessary to plant these high water users for Fiery Skippers and Giant Swallowtails. Lantana is more than enough to bring these into the yard. I wanted to attract butterflies less likely to be seen in the garden, as well as some of the migrants from Mexico. This involved a little more thought as to what to plant. Also, most of the plants I decided upon are not available commercially, so most of them I had to propagate from seeds collected in the wild.

For the early spring species like the Desert Orangetip, the Sara Orangetip, and the Pearly Marble, I sowed seeds of twist flower (Streptanthus carinatus ). I have had caterpillars of all three, though not every year. For some of our local skippers such as the Arizona Powdered-Skipper and Erichson's White-Skipper, I used native mallows like Abutilon, Herrisantia, and Sphaeralcea. Both skippers have successfully bred in the yard, with Erichson's using H. crispa and the Arizona Powdered-Skipper using A. abutiloides. I have had eggs layed on Sphaeralcea by the 'White' Common Checkered-Skipper. These native plants are considered weeds by all but the pure naturalist and would normally die a chemical death. For my garden they and other natives like goosefoot (Chenopodia fremontii ) and saltbush (Atriplex elegans ) are welcome. My goosefoot has, at times, been inundated by the nest-making caterpillars of the Golden-headed Scallopwing, a skipper whose food plant was first reported as recently as 1991!

Most butterfly gardeners neglect to add native grasses. This is probably due to their unavailability or to a general lack of interest. The food plants for grass-feeding skippers are still mostly unknown, and the possibility of making a scientific contribution from your garden is greatest in this area. I have found sideoats grama (Bouteloua curtipendula ) to be a fairly reliable food plant in the wild, and it has worked in my yard for the Orange Skipperling. Bamboo Muhly (Muhlenbergia dumosa ), a plant I use for research, has also attracted an egg-laying female Orange Skipperling or two. I have found caterpillars of the Violet Clouded Skipper on green spangletop (Leptochloa dubia ) a number of different times while the plants were still in their one-gallon containers!

Some of the plants I put in as nectar plants have turned out to be caterpillar food plants as well. I was elated by the appearance of Fatal Metalmark caterpillars on seep willow, one of my best nectar sources. It was the first time I had ever seen a caterpillar from that genus. The caterpillars make an annual appearance every June. I was also surprised at how great a backyard plant kidneywood has turned out to be. It has proven to be a good nectar source as well as a caterpillar food plant for both Marine and Ceraunus Blues. On numerous occasions I have observed ants carefully tending the small caterpillars for their sweet juice.

Final Act
Five years and ninety or so different plants later, my observations of this butterfly garden have ceased. Recently, my family and I purchased a home nearby and put the condo up for sale. Well over sixty species of butterflies have visited the small confines in the last five years. More than a third of that number have successfully bred on the plants provided for that purpose. The highest daily count was 26 species on April 7, 1995. There have been surprise visitors such as a Mournful Duskywing, a Clouded Skipper, a couple of Common Mestras, and a Silver-banded Hairstreak briefly visiting my bee bush one June afternoon. There have been surprising scenes, such as a Sheep Skipper laying eggs one evening just before sundown, or Boisduval's Yellows roosting side by side at night. There have been disappointments, as well. In five years I have never found a Pipevine Swallowtail caterpillar on my native Aristolochia watsoni, nor have I seen a Common Sootywing in the yard. And only once has a Variegated Fritillary come calling.

Hopefully, the new owner will appreciate and preserve my old butterfly garden. Now it's time to move on to the challenge of creating a new garden. The new home sits on nearly an acre and includes an established colony of Empress Leilias. I can hardly wait!

Jim Brock is coauthor of Butterflies of Southeastern Arizona (Tucson: Sonoran Arthropod Studies, 1991). He is an avid nature photographer and videographer.

30 Dec 1997 / Main Page