The lake is responsible for microclimates that are important to agriculture. Along its north shore is one of the richest areas of Canada's fruit and vegetable production; this southernmost tip, particularly in the area around Leamington, is known as Canada's "tomato capital". The area around Port Rowan has special trees which grow because of the "tempering effect of the lake", and species include tulip trees, dogwood, sassafras and sour gum. In this area there are many greenhouses which produce a "variety of tropical plants rarely cultivated so far north", including some species of cacti, because of the lake's tempering effect. Along the southeastern shore of Ohio, Pennsylvania, and New York is an important grape growing region, as are the islands in the lake. Apple orchards are abundant in northeast Ohio to western New York.