Plant Sale Preview: Attracting Pollinators to Our Gardens

Bee on a Formosa lily (Lilium formosanum) in the 
Page-Rollins White Garden. Photo by Robert Ayers.

By Jason Holmes

While visiting Mount Mitchell State Park in western North Carolina over the Labor Day weekend, I witnessed a native bee pressing open the lipped petals of the pink turtlehead (Chelone lyonii).  It made me think of the importance of that moment and yet how that bee had already visited hundreds of flowers that day in order to collect pollen on the side of her legs.  I quickly yelled to my son to come get an up-close view. This was a perfect opportunity to show him the importance of that little creature.

Insect pollinators may seem like a small part of our daily lives, but they have an enormous impact on us. Fortunately, gardeners’ interest in pollinators appears to be growing, as Duke Gardens saw when we offered pre-orders of a 6-plant “Pollinator Garden in a Box” preceding our Fall Plant Sale coming up on Saturday, Sept. 24. Within less than a week, we had reserved all 50 of the Pollinator Garden boxes we had prepared. We’ll have plenty of other pollinator plants at the sale, and the excitement over them is heartening for horticulturists like me, who are devoted to attracting pollinators to Duke Gardens and teaching visitors about these species’ roles in our lives.

Most people don’t realize that honeybees are not native to North America and that thousands of other insect species were responsible for pollinating many plant species before their introduction. Bees and wasps, flies, butterflies and moths, and beetles are among the thousands of plant pollinators across North America. These beneficial insects are responsible for all insect-pollinated fruits and vegetables that provide us with most of the nutritious vitamins and minerals that we need daily, and they also broaden our diets beyond just meat and wind-pollinated grain foods.

This act of pollination allows many types of plants to produce fruits and seeds, helping to create vigorous plants over many generations.

Approximately 75 percent of all plants in the world require animals for pollination. These animals are part of many humans’ daily diets, something worth keeping in mind as we seek ways to help the plants around us thrive.

A pollinator house in the
Charlotte Brody Discovery Garden.
Photo by Nick Schwab

At Duke Gardens, we celebrate and promote all types of pollinators.  In the Charlotte Brody Discovery Garden, a sustainable organic food garden, we donate over a ton of fruits and vegetables every year to local food relief organizations.  This is an amazing total, considering that we only garden on 2/10 of an acre.  We could never produce this incredible amount without assistance from the thousands of pollinators we see daily buzzing around the garden. In the Brody Garden, and in the Blomquist Garden of Native Plants, we have gardens designed specifically to attract these fascinating little pollinators.  We have nine honeybee hives in the Brody Garden. And with the help of dedicated volunteers, we have been building pollinator houses that we’re pleased to see attract many different beneficial species.

If you’re excited about helping pollinators, try planting species that will bring them to your garden. “Attracting Native Pollinators,” by The Xerces Society, is a great resource to learn more. If you already have these plants, consider leaving perennials longer through the fall and winter for habitat. Many of these species will create nests within the dead stems of perennial species.  Get creative and build pollinator houses or insect hotels.  They’re similar to bird houses, but you leave off the front wall and pack it with small stems of bamboo so that solitary insect species can build nests inside.  Remember, if you build it, they will come!

Jason Holmes is curator of the Doris Duke Center Gardens at Duke Gardens.

Fall Butterfly Workshops at Duke Gardens

Female eastern tiger swallowtail, black form.

The temperatures are finally falling, and that means it's time for our fall programs! This month, we have two fantastic adult education classes focused on butterflies, "Raising Butterflies: Monarch and Eastern Swallowtails" and the two-part "Tracking Butterflies in the Gardens." They will be taught by Lori Carlson, a volunteer in our horticulture and education programs.

Lori's interest in raising butterflies began in 2012 with the discovery of monarch caterpillars in her newly planted home butterfly garden. The following year, she and her husband began raising eastern black swallowtails in addition to monarchs. Their garden has grown to more than 5,000 square feet and includes more than 300 different nectar and host plants for butterflies and other pollinators. This year, a total of 49 different butterfly species (and still counting) have been sighted in their garden. Lori shares more about butterflies and her classes in the following article. 

Black swallowtail eggs on parsley.

Raising Butterflies

What began as a happy accident quickly became a passionate hobby for my husband John and me with the first set of monarch caterpillars we raised. We had no guides or references other than the knowledge found on the internet coupled with a lot of trial and error. Fortunately, our efforts were quite successful! 

Raising butterflies from caterpillars is an amazing process to witness, no matter how many times I experience it. In our garden, monarch caterpillars are typically found in late August/early September and rapidly progress through their life stages. This fall generation is the fourth monarch generation of the year, and this group will not complete its life cycle in two to six weeks like earlier generations. This group of monarchs will live for six to eight months, migrating to Mexico or Southern California for the winter and completing their lives there when they lay eggs in the spring. The black swallowtail butterfly also has a complicated life cycle, with at least three generations each growing season. The third generation of black swallowtails pauses for the winter in the chrysalis stage, emerging with the return of warm weather in the spring. This year marks our fifth season of raising monarchs and black swallowtails in our garden.

Black swallowtail caterpillar.

During "Raising Butterflies: Monarch and Eastern Swallowtails" on Sept. 20 from 6:30-8:30 p.m., I’ll guide you through the life cycle of the monarch and black swallowtail, instructing you on how to feed and care for your caterpillar or chrysalis. Attendees of the workshop will be provided a critter cage in which to raise the caterpillar; the cage will also serve to protect it as a chrysalis. One species-specific host plant will be included to feed to the caterpillar. I have also written a guide booklet to help you successfully raise your caterpillar to a butterfly.

Tracking Butterflies in the Gardens

Numerous species of butterfly can be seen at Duke Gardens, as well as in surrounding natural areas in the vicinity of Durham and Orange County. Duke Gardens serves as an excellent location to begin the hobby known as “butterflying,” as it contains many host and nectar plants of native butterfly species.

Female eastern tiger swallowtail.

My approach to identifying butterflies involves more than rote memorization of appearance or subtle variations between similar species. Butterflies seldom hold still for very long, and it can be difficult to spot those variations. Instead, I will focus on the behaviors, habitat, host and nectar plant, and seasonal appearance of groups and individual species. The best way to learn how to identify butterflies is to observe them in their habitat while they are nectaring or in motion. Binoculars and cameras can help with identification, especially of smaller butterflies. 

The first section of the "Tracking Butterflies" course, on September 9 from 1 to 3 p.m., will cover the larger, more obvious butterflies that people can’t help but notice, such as the ubiquitous eastern tiger swallowtail. There are approximately eight swallowtail species native to North Carolina, with five of them being fairly common to the Durham area. We'll discuss Batesian mimicry, when a harmless butterfly mimics the markings of a dangerous one to deter predators, so we can better distinguish which is which among the group of dark swallowtails commonly seen in the area. We'll also talk about other large butterflies such as the monarch, anglewings, sulphurs, and fritillaries. 

Gray hairstreak on verbena. Cuter than a kitten!

The second section, September 16 from 1 to 3 p.m., will cover the small to tiny butterflies that I often refer to as flying nickels and dimes, for that is approximately their size! Species in this category include the hairstreaks and skippers, which I think rival the cuteness of kittens in appearance. We'll address additional species as time permits.

Each class will be given ample time to explore the Gardens together and to be shown the location of host plants as well as favorite nectaring locations. This is an opportunity to try out your new identification skills and confirm your conclusions with me.

I'll provide you with online resources to help you with identification, as well as a list of locations in Durham and Orange Counties where you can continue to practice butterflying. 

To sign up for Lori’s classes, call 919-668-1707 or email us at gardenseducation@duke.edu. For more information about these and other classes, visit the events page of our website. And to start your own pollinator garden, consider pre-ordering a "Pollinator Garden in a Box," a new feature in conjunction with our Fall Plant Sale. Special thanks to Lori for her detailed photos.