Oaks may be our most important genus of trees. They have the highest ecological values of any native species, thus making an Oak the most important tree you can plant. Educating yourself on trees, about Oaks and focus on the long term importance of your efforts to plant trees will benefit future generations and our environment.
Oaks are very long-lived trees; 300 years on average and some species, such as White Oak (Quercus alba) can live to over 800 years. Oaks have more leaves than most other tree species and those leaves support numerous species of herbivorous larvae, especially the caterpillars of Butterflies and Moths. Native Oaks support over 450 species of Butterflies and Moths in our area. Their caterpillars are a food source for songbirds. More importantly they are a necessary food source for baby songbirds that need to eat proteins and fats in the form of insects, mainly caterpillars (over 90%). Studies by Doug Tallamy, University of Delaware professor, entomologist and author, and his students, found that one family of Chickadees with 5 babies required over 9,000 caterpillars to raise the young to fledgling age (17 days).
Native Oaks are by far the best at providing this food source. Oaks also produce acorns which provide food for many creatures including birds like Wild Turkeys, Woodpeckers and Blue Jays and mammals like Chipmunks, Squirrels and Bears. Oak acorns were a staple food for First Nations People historically.
Oaks can also play a role in mitigating climate change because of their longevity, carbon sequestration, oxygen production and water transpiration. A forest with Oaks protects our environment and supports numerous wildlife species (biodiversity).
In Southwestern Ontario, we have 9 species of tree size Oaks and 1 species of shrub form (Dwarf Chinquapin – Quercus prinoides). The 9 native Oaks include White Oak (Quercus alba), Swamp White Oak (Q bicolor), Burr Oak (Q macrocarpa), Chinquapin Oak (Q muhlenburgii), Pin Oak (Q palustris), Hills Oak (Q ellipsoidalis), Red Oak (Q rubra), Shumard Oak (Q shumardii) and Black Oak (Q velutina).
The easy to grow species for the home landscape include White, Swamp White, Burr, Chinquapin and Red. They can be surprisingly fast growing. To quote Doug Tallamy, “if there’s only one thing you can do to help our natural environment, it is plant an Oak”. I’ll go one step further, plant a few oaks. You’ll be glad you did.
Larry Cornelis
President Sydenham Field Naturalists
Red Oak Acorns 
Pin Oak Acorn 
Shumard Oaks have buttressed trunks 
white oak fall colours