Tree City USA
The Tree City USA program is a national program that provides the framework for community forestry management for cities and towns across America.
Communities achieve Tree City USA status by meeting four core standards of sound urban forestry management: maintaining a tree board or department, having a community tree ordinance, spending at least $2 per capita on urban forestry and celebrating Arbor Day.
Participating communities have demonstrated a commitment to caring for and managing their public trees. Together the more than 3,400 Tree City USA communities serve as home to more than 135 million Americans.
What's In My Tree?
Driving around town when foliage is the thinnest, you may notice stuff growing in the trees. People are concerned that all the unusual things are killing the trees and want to know how it should be removed. Only a few plants are harmful. Most are "just there" and do not harm the tree.
Many of the plants seen are "air plants" or epiphytes. Spanish Moss (Tillandsia usneoides) and Ball Moss are native plants and closely related to the pineapple. A symbol of the South, it can be found hanging from tree limbs in Live oak (Quercus virginiana) and Cypress (Taxodium spp.). Stems and leaves are slender and curly, and catch water and nutrients from dust. Spanish moss has no roots, so it is not a parasite of the host tree. We may see more air plants on weakened or damaged plants because of stress; foliage may become thinner. This allows more light to penetrate into the branches, stimulating the growth of air plants. So, air plants grow faster on stressed trees because the tree is weakened, but are not the cause of poor tree growth. Trees are not likely killed by Spanish or Ball moss. If air plants become so thick that they shade the leaves, growth might be slowed down. When a diseased or poorly attached limb supports these air plants which are heavy with rainwater, the branch could break.
Mistletoe (Phoradendron serotinum), a true parasite, grows in Laurel Oaks (Quercus laurifolia), Elms (Ulmus spp.) and a few other hardwood trees. At this time of year, it is very apparent in the thin foliage of our semi-deciduous trees. Mistletoe appears as a darker green ball of foliage on an otherwise bare tree canopy. This is one of the few things found growing on our trees which may harm the tree. If a tree is stressed from hurricane damage, construction impacts, disease or old age, this parasite can take its toll. Mistletoe can be cut out of the tree canopy. The branch should be cut back several inches below the connection point. This kind of trimming may not be possible on larger limbs of the tree.
Other inhabitants on the bark of our trees are numerous lichens, organisms composed of both fungi and an alga. The algae give the color and provide the food for the lichen, while the fungus gives protection and shape for these unusual plants. These gray, green, red or yellowish patches take up space on tree limbs and branches, but do not harm the tree in any way. Landscape perfectionists may find their appearance unappealing, and some people have been known to spray a fungicide; however, the University of Florida does not recommend fungicides for this purpose.
To learn more visit, http://solutionsforyourlife.ufl.edu/.
*Information for this column comes from the University of Florida IFAS Extension Service. Compiled by Palm Coast Urban Forester Carol Mini, using information from the University of Florida IFAS Extension Service.