Is My Tree Safe? Recognizing Conditions that Increase the Likelihood of Tree Failure

Figure 1. Dead branches pose threat to targets.Urban trees provide shade and beauty and the urban forest as a whole provides a wealth of benefits to neighborhoods and residents. But stresses from the urban environment may lead to problems that pose an unacceptable safety risk to people and property. It is a landowner’s responsibility to ensure that the trees on their property are safe. A key step in reducing the potential for tree-related injury or property damage is learning to identify common tree defects associated with increased risk of failure. This 5-page fact sheet highlights seven easily reconizable tree defects that homeowners and non-professionals in public agencies. may encounter in Florida. Written by Drew C. McLean, Andrew K. Koeser, Robert J. Northrop, and Gitta Hasing, and published by the UF Department of Environmental Horticulture, October 2014. (Photo by Gitta Hasing)
http://edis.ifas.ufl.edu/ep507

Tree Risk Assessment Methods: A Comparison of Three Common Evaluation Forms

Figure 2.  Urban trees can often impact multiple targets.All trees pose some level of risk to nearby people, structures, and utilities. As trees age or become weakened by pests, disease, and/or other stresses, a tree owner or manager may need to decide what risk level he or she is willing to accept and what modifications may be needed. Experienced arborists can aid in this decision process by conducting a professional risk assessment that specifies the likelihood of whole or partial tree failure, the consequences of such a failure, and the potential targets affected. A variety of risk assessment methods have been developed to guide professionals through the tree inspection process. In North America, three risk assessment methods have gained the greatest acceptance among tree care professionals, municipal urban forestry programs, and government agencies. This 8-page fact sheet was written by Andrew K. Koeser, Gitta Hasing, Drew McLean, and Rob Northrop, and published by the UF Department of Environmental Horticulture, November 2013.
http://edis.ifas.ufl.edu/ep487

Pyrus communis, Common Pear (FOR293/FR361)

Figure 1. Common pear (Pyrus communis)The showy flowers and manageable height of common pear makes it a favorable ornamental landscape tree. Some find the aromatic flowers and sweet edible fruits to be an additional plus; however, a pollinator specimen must be nearby in order for the female tree to produce fruit. Careful consideration should be taken when choosing a planting location, since the soft fruits can be messy if not harvested. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr361

Casuarina equisetifolia, Australian Pine (FOR298/FR366)

Figure 1. Australian Pine (Casuarina equisetfolia)Australian pine was originally planted in Florida in the late 1800’s as a windbreak and for shade. But soon thereafter it was spreading without help from humans. Today it is considered a category I invasive species in Florida, and the Division of Plant Industry strictly prohibits possessing, transporting, and cultivating this species. For those who find this tree in close proximity to their home, it’s a good idea to replace it since Australian pine is known to have a very low resistance to wind. Australian pine is commonly found growing on coastal shorelines since it thrives in salty, sandy environments. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr366

Tabebuia serratifolia, Yellow Trumpet Tree (FOR303/FR371)

Figure 1. Tabebuia serratifolia, Yellow Trumpet TreeThis deciduous tree is native to South and Central America is commonly planted in Florida as an ornamental landscape and shade tree. It has attractive bright, yellow blossoms produced in the absence of leaves. Once established, this tree is drought tolerant, making it easier to care for and less demanding on water resources. Yellow trumpet tree also has a relatively high tolerance to salt spray, and therefore is an appropriate street tree or yard specimen in coastal areas.This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr371

Hippomane mancinella, Manchineel (FOR302/FR370)

Figure 1. All portions of the manchineel tree are poisonous.This poisonous tree is native to southern Florida, the Keys, many of the Caribbean islands, Mexico, and Central America. Though it is poisonous to humans and many animals, iguanas are eat the fruit and sometimes live among the tree’s limbs. It’s found along the seacoasts and in brackish swamps where it grows among mangroves. Each leaf has a small gland where the leaf joins the stem. The bark is reddish-to-grayish brown and cracked looking. Flowers inconspicuous, but the spikes or leafless stems that the flowers emerge from are visible. The fruit is bright-green and looks like a small apple. This 2-page fact sheet was written by Michael G. Andreu and Melissa H. Friedman, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr370

Fortunella spp., Kumquat (FOR300/FR368)

Figure 1. Kumquat (Fortunella spp.)Many people find kumquat trees attractive and useful yard specimens. Their dark green leaves and contrasting bright orange fruits give them ornamental quality, and their relatively small size makes them easy to care for once they’re established. Because kumquats generally require less care than other citrus trees, they may be a good choice for gardeners with less time or experience, but who still desire an attractive and tasty citrus tree. If space is an issue, kumquats also do well in containers as long as they receive proper sunlight and watering. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr368

Gleditsia aquatica, Water Locust (FOR301/FR369)

Figure 1. Water Locust (Gleditsia aquatica), Tosohatchee Wildlife Management Area, Orange County, FL, July 2012Water locust’s wide, spreading root system and affinity for hydric conditions makes it a useful specimen for erosion control on wet banks of freshwater systems. While not widely available, planting this tree in residential yards or other public locations may be less than ideal, since the long and sharply pointed thorns on the main trunk and branches can be hazardous. This deciduous tree is native to Florida. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr369

Callistemon salignus, White Bottlebrush (FOR292/FR360)

Figure 1. Callistemon salignus, White BottlebrushNative to Australia, this evergreen tree has use as an ornamental tree that produces moderate shade along a street, median, or yard. The unique flowering structure is eye-catching and it can be pruned for use as a decorative hedge. Its tolerance of many different soil types and droughty conditions makes it easy to care for after it’s been established. This 2-page fact sheet was written by Michael Andreu, Melissa Friedman, Robert Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr360

Cassia grandis, Pink Shower (FOR294/FR362)

Figure 1. Detail of Cassia grandis L.f. blossoms and budsThe name “pink shower” comes from the bright pink blossoms that this tree produces. It is sometimes called “stinking tree” because the pulp in its pods has a very strong smell. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr362

Cassia leptophylla, Gold Medallion Tree (FOR295/FR363)

Figure 1. Gold medallion tree (Cassia leptophylla) in bloomThe gold medallion tree is planted primarily as a shade tree or as a decorative specimen for the yard or street. Many people like this tree because of its fast growth rate and showy, bright yellow clusters of flowers that bloom in the summer months. This tree loses its leaves for a very short period each year, but leaves are quickly replaced. Pruning the tree to one main leading stem from which major branches are attached can help increase its strength and sturdiness against strong wind events. The golden medallion tree is also naturally pest resistant, and as long as it is grown in areas where the temperature does not drop below freezing, it is an easy tree to care for. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr363

Cassia afrofistula, Kenyan Cassia (FOR296/FR364)

Figure 1. Detail of Cassia afrofistula (Kenyan Cassia)The Kenyan cassia can be used as a showy ornamental tree or shrub, with its dark foliage and bright yellow flowers. Some people find the seed pods to be unattractive and prune the tree after it flowers to prevent pods from developing. This tree tolerates a wide range of soil types and can be used in a garden, park, patio, or streetscape setting. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr364

Leucaena leucocephala, White Leadtree (FOR299/FR367)

Figure 1. White leadtree (Leucaena leucocephala)In Florida, white leadtree is a prohibited species and therefore is not used in commercial applications in the state. However, in its native range it is used as a source of charcoal, fuel, and lumber. It has also been planted as a windbreak for crops such as coffee and cocoa, and some ranchers use the tree as a source of both shade and forage for cattle, with the pods being an excellent source of protein. In addition, as white leadtree forms a well-developed taproot, it has been planted to assist with erosion control. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr367

Cassia javanica, Pink and White Shower (FOR297/FR365)

Figure 1. Clustering flowers of Cassia javanica (Pink and White Shower)Cassia javanica is planted primarily as a decorative shade tree. Many people consider pink and white shower to be aesthetically pleasing because of its pink and white blooms that emerge during the summer months. Because its leafless season is so short, it can be a good shade tree throughout the year. Its rapid growth rate makes it an ideal tree for homeowners looking to increase their tree cover. And its natural resistance to pests increases its desirability as a landscape tree that is commonly used as an ornamental street tree. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr365

FOR265/FR327 Duranta erecta, Golden Dewdrop

FOR265, a 2-page fact sheet by Michael G. Andreu, Melissa H. Friedman, Mary McKenzie, Heather V. Quintana, and Robert J. Northrop, describes this small evergreen tree found in the sun belt of the United States, including Florida, Louisiana, Texas, Arizona, California, and Hawaii — scientific and common names, description, allergen, and applications. Includes references. Published by the UF School of Forest Resources and Conservation, June 2010.
http://edis.ifas.ufl.edu/fr327

FOR266/FR328 Ficus citrifolia, Shortleaf fig

FOR266, a 2-page fact sheet by Michael G. Andreu, Melissa H. Friedman, Mary McKenzie, Heather V. Quintana, and Robert J. Northrop, describes this semi-deciduous fig tree that is native to Florida and naturally found in tropical hammocks throughout south Florida, the Caribbean, the Bahamas, the West Indies and some regions in Central America — scientific and common names, description, allergen, and applications. Includes references. Published by the UF School of Forest Resources and Conservation, June 2010.
http://edis.ifas.ufl.edu/fr328

FOR267/FR329 Carya aquatica, Water Hickory

FOR267, a 2-page fact sheet by Michael G. Andreu, Melissa H. Friedman, Mary McKenzie, Heather V. Quintana, and Robert J. Northrop, describes this native deciduous tree found in wet but well-drained soils along stream banks and flood plains, ranging from the eastern Carolinas, south to central Florida, and west to Eastern Texas — scientific and common names, description, allergen, and applications. Includes references. Published by the UF School of Forest Resources and Conservation, June 2010.
http://edis.ifas.ufl.edu/fr329

FOR255/FR317 Crataegus marshallii, Parsley Hawthorn

FOR255, a 2-page fact sheet by Michael G. Andreu, Melissa H. Friedman, Mary McKenzie, Heather V. Quintana, and Robert Northrop, describes this small native tree found in open to partially shaded areas along the moist edges or slopes of floodplains, river banks, and wet woodlands throughout the southeastern United States — scientific and common names, description, allergen, and applications. Includes references. Published by the UF School of Forest Resources and Conservation, June 2010.
http://edis.ifas.ufl.edu/fr317

FOR256/FR318 Fraxinus caroliniana, Pop Ash

FOR256, a 2-page fact sheet by Michael G. Andreu, Melissa H. Friedman, Mary McKenzie, Heather V. Quintana, and Robert Northrop, describes this native deciduous tree found in the wet soils of swamps, flatwoods, bottomlands, and riverbanks throughout the southeastern United States — scientific and common names, description, allergen, and applications. Includes references. Published by the UF School of Forest Resources and Conservation, June 2010.
http://edis.ifas.ufl.edu/fr318

FOR246/FR308 Phoenix sylvestris, Wild Date Palm

FOR246, a 2-page fact sheet by Robert J. Northrop, Michael G. Andreu, Melissa H. Friedman, Mary McKenzie, and Heather V. Quintana, describes this slow-growing palm native to India and southern portions of Pakistan – scientific and common names, description, allergen, and applications. Includes references. Published by the UF School of Forest Resources and Conservation, May 2010. http://edis.ifas.ufl.edu/fr308