Fruit are borne on short vertical shoots called uprights. An upright can grow erect for one or two seasons before its weight bends it downward and new vertical growth is produced at the tip or from axillary buds along the stem. Runners grow horizontally. In very vigorous beds runners may grow across the tops of vines. Cranberry leaves are small and attached to the stem with a very short petiole.
Leaves typically persist for two years, then fall to the ground.
The buds are formed in late summer the season before the open and grow. The buds must survive through Wisconsin winters in order to produce a crop the following year. Critical times for the crop ware when the buds form in the late summer and when they open and begin to grow the following spring. Wisconsin cranberries flower in late June and early July. The blossom period lasts for three or four weeks depending on the weather.