All summer long, wild blackberries and wild trailing blackberries, also referred to as dewberries, are ripening somewhere in the United States. Exactly when the tasty berries are ready for picking depends on what area of the United States you live in.
Wild blackberry season starts in May and continues into September. In warmer climates, such as in Texas and southern states, the berries start ripening in May and June. But in cooler climates such as in the Pacific Northwest and mountainous areas, the berries start ripening in July and continue through August.
Blackberries ripen over a period of several weeks. You'll want to head to your favourite patch every two to four days to pick the newly ripened berries.
Weather conditions play a large role in when wild berries actually ripen. Drought, too much rain, late spring frosts and the past winter's snow pack can all have an effect on the crop.