Where do you find red berries in runescape?

Redberries can be found west of the south-east mine in Varrock.

You can also find a single bush just to the west of the pig-pen that is west of Draynor Village or buy 10 units for 3 gold each from Beefy Bill's supplies (general store) along the road north to the River Lum/ south away away the River Lum/ Varrock