In case you thought it was too late to fertilize, the Ontario Ministry of Food and Agriculture Bulletin for October 15, 2013 says fall is a fantastic time to do so. The bulletin states:
Up to half of the annual fertilizer requirement may be applied to landscape plants, after top growth ceases (October). Autumn is a major root growth period for woody and herbaceous perennials. Roots will grow and absorb nutrients whenever soil temperatures remain above 5°C (conifers will grow at even lower temperatures, often into December). Take advantage of this fall growth period by applying up to 50% of annual fertilizer now, especially nitrogen and potassium. By splitting annual fertilizer applications into two or three events, plant roots have more opportunities to absorb nutrients and that means less potential for loss to non-target areas. When the applications are made by deep-soil injection, fall fertilizing can be another opportunity to create to aerate tired landscape soils.