Picking blackberries grow throughout the United States and Canada. Blackberries are typically ripe for the picking, according to Foodfit.com, around June in the southern states and July in the northern states and Canada. Unlike many fruits, blackberries stop ripening the moment they are off the bush, so it is important to select only berries that are ripe and ready for consumption.
Newly formed berries are completely green, and berries that are not yet ripe are red. Ripe berries are black. To obtain berries with the least amount of tartness, look for berries that are no longer shiny and have a dull appearance. These blackberries are at the "dead" stage and are ready to fall off the bush naturally. This is when they are at their sweetest.
Gently pull away from the bush when picking blackberries. Be careful not to squeeze the berries, as they are easily crushed and extremely soft. To store blackberries, keep them at room temperature or in the refrigerator for two or three days. To freeze them for up to six months, begin by placing them in the freezer on cookie trays overnight and then placing them in freezer bags or moisture-resistant containers.