Vertical tiller

A system (100) for mixing soil while protecting underlying weed fabric, the system comprising:

• a) a tiller assembly comprising a helix (220) the helix comprising a plurality of wings (230) with each wing comprising a first vertical return (237) attached to an outer edge (222) of the helix, the first vertical return also attached to a cambered transition (235) with the cambered transition attached to a sweeping distal edge (232) with the sweeping distal edge attached to a normal edge (243) with the normal edge attached to a second vertical return (239) with the second vertical return attached to the outer edge of the helix;
• b) the helix further comprising a turned leading wing (250) the turned leading wing disposed at the lowest end of the helix, the turned leading wing comprising a distal edge piece (255) in angled attachment to the turned leading wing;
• and
• c) the tiller assembly centrally attached to a shaft (210) the shaft having an inferior end centrally attached to a rider disc (300) the rider disc comprising a outer circular wall (330) and a lower circular surface (320).