The dull-blue colored dewberries makes one think that the fruit is covered in mold, but that's absolutely not the case. These blackberries but are generally juicier and just as sweet as the common blackberry. Dewberries are very common on sunny areas in the dunes and along large rivers and railway embankments. They grow in calcium-rich soils where organic material decomposes quickly, releasing a lot of nitrogen. Dunes are often richer in calcium than other soils, which explains why dewberry is found there. When there are no berries for comparison, you can still easily identify dewberry from blackberries from the number of leaves. Dewberry has three, blackberries have five. Unlesss you've found a hybrid dewberry with a blackberry or even a rasberry.