The dramatic shift toward native and sustainable gardening in the last decade is remarkable. As images of giant plumes of oil spilling into the Gulf gave us all reason to despair, I drew deep comfort from seeing so many fellow gardeners join the green revolution by converting their plots into islands of biodiversity, or by plowing up their lawns and planting vegetable gardens. These small acts of resistance are reasons to hope.
|Plants being propagated by tissue culture in a lab.|
Now as weird science as all of this sounds, it’s not terribly different than taking a cutting of your favorite plant to share with a friend. The great advantage of tissue culture—and other asexual propagation techniques—is that it creates predictable plants. Gardeners can be guaranteed that the Itea virginica they purchased will have the deep crimson fall color, the prolific blooms, and the cascading stems of the ‘Henry’s Garnet’ cultivar. It also offers a much-needed alternative to native plants that were taken from the wild, a once prevalent practice.
The great problem with asexual propagation is that as we lose native habitats to development, the natives we are replacing them with represent a much narrower genetic pool than what existed. More often than not, the native plant you buy at your local retail nursery was probably populated by tissue culture from a native population somewhere far away. For example, how native is a plant that was derived from a source in Tennessee, propagated in a petri dish in Oregon, shipped as a liner plant to Michigan, and then delivered to a retail nursery in Massachusetts? By the time that plant hits your garden, its passport is full.
|On the left, an unplanted Panicum in Texas (photo by Rick Darke); on the right, the Panicum cultivar 'Cloud Nine'|
|Left: Liatris scariosa var. novae angliae only exists on Martha's Vineyard and Nantucket; Right: Liatris spicata from the Midwest|
|The copper tones of Little Bluestem collected from local seed sources have a deeper color than Little Bluestem from off island..|