Not only is it important to plant new trees, but to preserve the biodiversity of our Carolinian forest. Native species are those which grew naturally in southern Ontario prior to European settlement. Often cities plant non-native species that grow quickly and are designed to have certain colour and form characteristics.

However, some of these exotic species, such as Norway Maple (Acer platanoides) reproduce aggressively and out-compete native species in ravines and other natural areas. It is important to preserve the diversity of our forest by selecting species suitable to our geographic area.

Native plants have adapted to local climatic conditions over thousands of years; once established they are able to stay healthy with little watering and without the use of chemical pesticides or fertilizers. Native plants are also important to the survival of our urban wildlife, such as songbirds and butterflies, since they provide essential food and shelter.