I am looking for a privacy tree, not cedar or evergreen, needed to block neighbours backing onto property. Their lot is higher than ours due to retaining wall. We have installed a black-brown horizontal slat wood fence. I would like to see the fence if possible once the trees grow. I would we installing 4 or 5 trees along back of property and would like something that is fast growing . What do you suggest ?
Thank you for contacting Toronto Master Gardeners with your question about a fast-growing tree suggestion for privacy purposes.
The Arbor Day Foundation https://arbordayblog.org/landscapedesign/the-fastest-fast-growing-trees/provides an excellent description of a selection of deciduous fast growing trees; their qualities, growth rate, sound tree care, and annual pruning practices. This is an American blog so bear in mind that the USDA hardiness zones are considered to be one zone higher than our Canadian recommendations. In the Greater Toronto Area we are generally considered to be in Canadian hardiness zone 6. The site features a number of trees that would be appropriate for your needs, and some, such as the Quaking Aspen Populus tremuloides or River Birch Betula nigra, have trunks that will stand out handsomely against your black-brown fence.
Once your trees’ root systems are well established, “limbing up” or removing lower side branches and ensuring a single trunk develops, will expose your fine decorative fence. You may then wish to train the canopy into a “hedge on sticks” or pleached trees which will provide room at ground level for small annual or perennial decorative plants and a leafy screen above the fence. Autumn colour is a feature of most of the trees listed, and the beech and hornbeam trees hold dried leaves, bleached to lovely pastels hues, throughout the winter, losing them only as the new leaves unfurl in Spring.
Plant large trees in locations where their root systems wont affect other plants. Always plant trees away from utility lines, homes, and driveways to minimize damage should their branches break during storms. Pay attention to septic lines and sidewalks, which can be disrupted by roots.
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/visual-guides/native-trees-for-missouri.aspx This website from the respected Missouri Botanical Garden lists both native shrubs and trees suitable for our climate, with a description, cultural information and a photograph of the tree.
LEAF is a Toronto based organization working on reforesting the city with native trees. It is an excellent source of information and trees. https://www.yourleaf.org/
We wish you every success with your thoughtful and interesting project.