I live near High Park and I was considering planting european beech trees or hornbeam but I just came across some information about diseases in them. Is this a serious enough condition to find another tree and if so are there any disease free trees like the e beech or hornbeam?
Thank you for contacting Toronto Master Gardeners for information on tree diseases, particularly in Hornbeam and Beech trees. There are a number of different types of Hornbeam (Carpinus betulus) and it depends on your landscape requirements: hedging, individual shade or small specimen tree. As a specimen with height of 250cm, Carpinus Betulus ‘Columnaris Nana‘ is slowing growing and low maintenance. An upright shade tree, Carpinus Betulus ‘Emerald Avenue‘ has a strong central leader and branching habit. See photo below.
Carpinus Betulus ‘Frans Fontaine‘ is narrow, vertical and excellent for hedging. On our Toronto Master Gardener website, type in “hornbeam” and you’ll find many answers on Hornbeam diseases and solutions. Root rot can result from moisture in clay soil without good drainage. Powdery mildew may appear in shaded locations with high humidity. Canker disease grows on dead or dying branches and timely pruning can prevent this problem from attacking the trunk. Heart rot and decay fungus are caused by lack of pruning, stress from improper watering and vigilance if pests appear and can be removed.
European Beech trees have been decimated throughout North America by beech scale, bark-cankering fungi, beech leaf disease and beech leaf-mining weevil. These are all imported diseases and the initial beech bark infestation began in Nova Scotia and spread down through the eastern U.S. regions. European Beech may not be the best choice of tree to plant.
The best advice for maintaining healthy plants and trees is to research the exact growing conditions required. This includes analyzing your location for wind, sun, soil and future height/width expectations. Crowding, lack or excessive moisture, impoverished soil and lack of sun can promote disease. As far as hardiness growing zones, Toronto is in Canadian Zone 6 or USDA Zone 5. In the High Park area, with the moderating influence of Lake Ontario, your zone is Canadian Zone 6B.
Some USDA Zone 5+ trees known to be disease resistant are: Kousa Dogwood (Cornus Kousa), Persian Parrotia (Parrotia Persica), Chinese Fringe Tree (Chionanthus retusus), Ginkgo (Ginkgo biloba), Paperbark Maple (Acer griseum) and Japanese Pagodatree (Sophora Japonica).
One of the best ways of sustaining local ecosystems is to use native plants and trees. The City of Toronto website below lists many plants and trees suitable for Zone 6 gardens.
Above is a comprehensive tree planting guide written by Toronto Master Gardeners. When you decide on the right tree for the right place in your garden, best wishes for an enjoyable and long-term companionship with your new trees.