Managing Tree Risk in Public Gardens: From Uncertainty to Understanding 

This three-part webinar series was made possible through the support of The Davey Tree Expert Company. This series will help attendees understand the...

In gardens where woody plants abound, arborists are key members of our horticultural teams- whether they're on staff full time or consult as needed. They help to care for sick trees and damaged trees, but they also keep healthy trees healthy...and so...

Needlecast and needle blight are terms applied to a variety of foliage disorders of many coniferous species. These diseases are usually more severe on young trees or on trees growing outside of their natural range. Disease severity and corresponding...

Learning to distinguish the symptoms of lightning strikes is a valuable tool for arborists, landscapers, pest control companies, and gardeners. The symptoms may be confused with other causes such as lethal yellowing disease (Candidatus palmae...

Emerald ash borer (Agrilus planipennis) was first discovered in southeastern Michigan in 2002. Accidentally introduced on solid wood packing material from Asia, EAB has since spread to nearly all states within the native North American range of its...

Six elements are required in small amounts for the growth and development of plants. These are referred to as micronutrients: iron (Fe), manganese (Mn) copper (Cu), zinc (Zn), molybdenum (Mo), and boron (B). Only two of these, iron and manganese, are...

Sonic tomography, or the use of sound waves to detect decay in trees, is a relatively new technology available to arborists.  This technology uses the differential speed of sound as it moves through solid wood, decayed wood, or hollow space to create a...

Thousands of trees are struck by lightning every year. These trees will have varying degrees of damage ranging from complete shattering and destruction of the tree, to a slow lingering death, to virtually no apparent damage at all (Figure 1). When...

Conifers are commonly planted in North America to provide year-round screening, as windbreaks or as focal trees in the landscape. However, conifers including certain species of spruce, pine, hemlock, cedar and fir planted in northern areas of North...

Nate Siegert, Ph.D., USDA Forest Service, discusses the latest information pertaining to the Emerald Ash Borer (EAB) and its continued spread across the urban forests of the U.S. and Canada. Learning Objective: Attendees will better understand the...

Oak decline is a slow-acting disease complex that involves the interaction of biotic and abiotic factors such as climate, site quality and advancing tree age. Oak decline occurs more commonly among red oak species, but white oaks are susceptible as...

Iconic tree species include those native trees that once dominated the typical American city landscape. The American elm and chestnut are the first two that come to mind, and now ash trees are similarly under significant threat of loss. The USDA Forest...

Tree defects such as co-dominant leaders, girding roots and buried trunk flares, present at time of planting, cause failures and decline long after the warrantee period has expired.  Landscape architects may go to nurseries to tag trees; but often...

Ice or snow loads can cause branch breakage or failure of entire trees and shrubs. Branches or entire trees that fall in storms can impact homes, vehicles, power lines and block roads. After a storm, the first priorities are safety and restoration of...

Insect and disease infestations pose major threats to several North American forest tree species.
Scientists and managers from throughout the United States Forest Service developed a conservation priority-setting framework for forest tree...

North American forests and forest management institutions are experiencing a wide range of significant ecological disturbances and socioeconomic changes, which point to the need for enhanced resilience. A critical capacity for resilience in...

The American chestnut, whitebark pine, and several species of ash in the eastern United States are just a few of the North American tree species that have been functionally lost or are in jeopardy of being lost due to outbreaks of pathogens and insect...

As the pace of urban development increases, urban green spaces, and urban trees in particular, come in direct conflict with bulldozers and backhoes. With careful early planning and an understanding of how tree damage occurs, strategies for tree...

This is an example of how a historic landscape and public garden used GIS to map, track, and monitor tree health on their grounds. The presentation highlights how one might be able to use GIS at their public garden and some of the key features GIS...

Trees are one of the most important display pieces in every Garden due to their size, presence, and impact on light levels. In this session, two horticulturalists who are experts at tree care will tackle two major issues in Public Gardens—construction...