This is the month of the most rapid increase in sugar production. The sun is still high in the sky, air is warm and fruit maturation reaches its peak. As a precaution, no more pesticides are applied within a month of the expected harvest. The whole month is marked by preparing for harvest, or crush. The Niagara variety of juice grape is the first to be harvested, usually around mid-September. Concord juice grapes follow about 7-10 days later. On the wine side, Baco Noir is one of the earliest French hybrids to be picked, usually by mid-September. Harvest continues by variety, and the viniferas will be picked throughout the fall and into early November.

Throughout September and October, the fields are monitored for sugar and acid levels to ensure optimum fruit maturity and quality, establishing the optimum time for picking. From September to October, harvest is in full swing. Most of the juice grapes have been picked by October and wine grapes continue to be harvested. Once everything is picked, post-harvest spraying is done to protect against mildew, which would injure the wood and affect the vines’ ability to over-winter. By the end of the month, there is usually only a small amount of late harvest varieties, such as Cabernet Franc and Cabernet Sauvignon, still on the vine. Grapes for Icewine are also left on the vine, and Icewine nets are applied to protect the berries from hungry birds.

Once the harvest is complete, the fields are prepared for winter. Young and more sensitive vines are hilled up with soil. This is an actual physical covering on the crown of the grapevine with soil. This creates a ridge that keeps water from accumulating in the vines and protects the crown (located at ground level) from extreme drops in temperature. In the vineyards, the grower digs furrows to assist in surface run-off of excess water. Too much water in the fields will kill the vines. Repairs to the trellis systems that may have been caused by the harvester are done at this time. By late November, growers prune more hardy juice and wine varieties.