Propagation and Replacement of Historic Plant Specimens
SPNEA and other preservation-minded organizations have made special efforts to preserve the genetic material of historic specimen plants at their sites in anticipation of the day when it will be necessary to replace them. At SPNEA's Lyman Estate in Waltham, Massachusetts, the horticulture staff maintains a historic plant nursery in collaboration with the National Park Service and Harvard University's Arnold Arboretum. Here, propagations from historic plants are made, potted, and grown until they are large enough to be transplanted into their landscape settings.
If there is a specimen tree or shrub you would like to propagate, the process is not difficult.
It is best to take a cutting right after the newest growth has become slightly woody. The cutting should be four to six inches in length from the growing tip of a branch, and the cut should be made on a sharp angle. Some plants root at the leaf nodes, and some along the entire stem. Make sure to remove any leaves that would be below the rooting medium. Dust the cut with a rooting hormone with or without fungicide in it. There are different strengths of rooting hormones, the number on the package usually corresponds to the strength. The stronger hormones are used on woody plants that can be difficult to root, like camellias.
Cuttings can be rooted in a variety of media, including coarse sand or a mix of fifty percent sand and fifty percent perlite, in a shallow pan or pot with drainage holes. Thoroughly saturate the mix with water. Make holes for the cuttings, insert cuttings, and firm the medium around them. To create humidity, you can set the cuttings inside a clear plastic bag, tied closed. Place in a shady area and make sure the medium does not dry out. Depending on the species, you will see roots in a few weeks to a few months.
For more technical facts and descriptions, along with other propagation techniques, we recommend an excellent reference book, Alan Toogood's American Horticultural Society's Plant Propagation, New York: DK Publishing, 1999. After experimenting with different techniques, you will find propagation rewarding and fun.
ABOVE LEFT Horticulturist Mary Nessel stakes plants in the nursery.
ABOVE RIGHT TOP Pear on a young pear tree grown from a cutting for Petersburg National Park in Virginia.
ABOVE RIGHT BOTTOM Young apple trees grown from grafts at SPNEA's Gropius House, Lincoln, Massachusetts.