LSU AgCenter Horticulturist
(06/12/20) June 22 through 28 is National Pollinator Week, and the focus is “Pollinators, Plants, People, Planet,” according to www.pollinator.org.
This not-so-well-known celebration was declared 13 years ago when the U.S. Senate designated the third week in June as “National Pollinator Week.” This helped make pollinators a central focus in an effort to tackle the urgent issue of declining pollinator populations.
It is a celebration of the valuable ecosystem services that bees, birds, butterflies, bats, beetles and so many other pollinators provide to our plants.
I’ve written about the types of ornamental perennial and annual landscape plants that attract pollinators to your landscape. This time I’d like to focus on native plants and their role in native insect species survival.
Researchers are concerned about recent declines in some butterfly species like the monarch in addition to honeybees. They believe the declines in these species could be an indicator that more pollinators are in trouble. The fates of pollinators and their host plants are connected.
Native pollinators pollinate more than 75% of the world’s flowering plants, including our fruits, nuts and vegetables. In fact, for 250 million years, plants and insects have coevolved over time into highly specialized partnerships. For example, certain fig trees can only be pollinated by a very specific wasp.
It’s no coincidence that insects have evolved to emerge at the exact time when their host plant is flowering. But changes in climate, threats from invasive plant species and habitat destruction are destroying native plants as well as their pollinators. These pollinators are also threatened by parasites, disease and insecticides.
As more and more land is developed, pollinators lose the plants that support them. Miles of open land turned into urban development or agricultural crop production lead to a fragmented and disappearing native plant habitat. This reminds me of a line from the 1970 song by Joni Mitchell, “Big Yellow Taxi” — “They paved paradise and put up a parking lot.” For you younger readers, the Black Crows and now Harry Styles have covers, showing just how significant the problem still is today.
Two centuries ago, the southeastern United States was covered in hundreds of thousands of acres of natural grasslands that stretched from Texas to Florida. I bet you never imagined Louisiana as a prairie. At one time it was a 2.5-million-acre feature in the southwestern Louisiana landscape, according to researchers.
Grasslands and prairies are complex ecosystems that provide habitat to hundreds of diverse plants and pollinators. The Cajun Prairie Gardens in Eunice has restored prairie with hundreds of species of native plants that were once found here.
Some of the plants they work with at one time grew as part of a natural grasslands that featured many native grasses, including yellow Indiangrass (Sorghastrum nutans), big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), eastern gama grass (Trypsacum dactyloides), switchgrass (Panicum virgatum) and brownseed paspalum (Paspalum plicatulum). Muhly grass (Muhlenbergia capillaris) is another native that is readily available at local garden centers and can be a gorgeous addition to the landscape.
Besides grasses, the prairies included herbaceous perennials such as compass plant (Silphium laciniatum), milkweeds (Asclepias spp.), blazingstars (Liatris spp.), mountain mints (Pycnanthemum spp.), bergamots (Monarda spp.), obedient plant (Physostegia spp.), coreopsis (Coreopsis spp.), native sunflowers (Helianthus spp.), black eyed-Susans or rudbeckia (Rudbeckia spp.) and many more.
Lands that are restored to prairie have the potential to bloom from mid-February to the end of November, supporting many species of butterfly and other pollinators.
The plants vary just like the original prairies, from dry patches to wet areas that hold water. Some species of plants that do well in wet areas are blue stars (Amsonia spp), milkweed, crinum lilies, hibiscus, spider lilies (Hymenocallis spp), Louisiana irises and rushes (Juncus spp.). Other native shrubs such as buttonbush (Cephalanthus occidentalis) Henry’s Garnet Virginia sweetspire (Itea virginica) and rose mallows (Hibiscus moscheutos) do well in wet areas.
American beautyberry (Callicarpa americana) is another great native shrub that prefers good drainage. Sunflowers, yaupon hollies, sages, salvias, bergamots, coreopsis, compass plants and black-eyed Susans are more drought tolerant.
You can help native pollinators by dedicating a portion of your landscape to these native plants. Cut out some of the manicured grass and turn it into a native garden. Natives survive with little to no inputs, all while supporting native pollinators. You can be a part of this restoration of prairie gardens representing the last bits of native habitat in Louisiana.
The good news is that every plant counts, and even small actions by individuals can help. You can use the suggestions here or visit the Ladybird Johnson Wildflower Center at www.wildflower.org and choose the “Native Plants” tab to find flowers that will work in your USDA hardiness zone. Urban dwellers can create habitats that attract pollinators too by planting native plants in window boxes or containers.
Pink muhly grass is a popular and widely available landscape plant that attracts pollinators. LSU AgCenter file photo by Allen Owings
Monarch butterfly caterpillars feed on tropical milkweed plants. Photo by Heather Kirk-Ballard/LSU AgCenter
Bees are important pollinators. Photo by Heather Kirk-Ballard/LSU AgCenter
A hummingbird feeds on agapanthus blossoms. Photo by Martha Stafford