It was a chilly day back in January, 2015, when my siblings and I received an email from our sister, the Curator of Collections at Historic Jamestown in Virginia, the first permanent English settlement in the New World. On this historic stretch of land, she spied a dense mass hanging from a loblolly pine tree (Pinus taeda) on the edge of the James River.
“Can someone please tell me what that almost round ball of living needles in the tree is?” she wrote.
A brother answered, “Mistletoe?” A sister answered, “Do you think a squirrel is living in there?”
I was fairly certain what it was…. “It’s a witches broom!” And I was excited to see it. A witches broom is an abnormal growth in a tree and can occur on a number of conifers and deciduous trees but seems to be most often spotted in pines. It is caused by numerous stress factors…. fungi, bacteria, viruses, mites, genetic mutations and several other factors and they can originate on different sections of a tree. This one developed on a terminal bud of a lower limb of the pine.
Most people just prune out the infected branches in their landscape but there are a number of folks who search for these genetic mutations in pines to propagate dwarf conifers. These witches broom hunters will harvest the growth by climbing a tree and cutting it out, using a shotgun to snap the limb, or by cutting down the entire tree. With a little luck and expertise, the broom can produce slow-growing and dense dwarf trees either by grafting to rootstock or from seeds.
At the JC Raulston Arboretum in Raleigh North Carolina, dwarf loblolly pines have been successfully grown from seeds in cones from witches brooms. Planted from 1964 to 1967, the dense, slow-growing dwarf loblolly pines have ornamental value. Hard to find, but the ‘Nana’ seedlings are available.
“Can you reach it?” I asked my sister.
“No, it’s too high up and over the river.”
“Well, keep an eye on it…” I said. “If it falls, let me know.”
And so she watched the mass for 3 years and sent me pictorial updates through all the seasons and all weather conditions.
In this sunny day photo below, I could see the presence of pine cones in the mass… a good sign as seeds from the cones have a better chance of developing into dwarf plants.
Last week the witches broom finally fell. A colleague at work, also keeping an eye on the growth, discovered it and reported it to my sister… who called the local cooperative extension agent…. who put the word out.
The broom was happily collected by Bradley Roberts, Curator of Herbaceous Plants at the Norfolk Botanical Gardens and a member of the American Conifer Society. He will try to propagate it.
Another fun horticulture adventure ends for us. Now we wish all the best to Bradley as he begins his adventure in propagating Historic Jamestown dwarf loblolly pines!