Derek Maguire, 55, and Neil Snazel, 42, both of Manchester, worked together to bring the Class A and Class B drugs in 15 crates from the Netherlands.
Maguire's nephew, daughter and her boyfriend, all from Manchester, were then employed to distribute the drugs.
All five were sentenced at Manchester Minshull Street Crown Court.
Maguire, 55, of Harbury Crescent, Manchester, was found guilty of eight charges concerning the production, possession and supply of drugs.
Snazel, 42, of Kenworthy Lane, Manchester, was jailed for 14 years after admitting three similar offences.
The pair were caught after Thames Valley Police seized a crate addressed to a courier in October 2015 and found a lawnmower containing 175lbs (80kg) of MDMA - the active ingredient in ecstasy pills.
National Crime Agency (NCA) officers went on to discover 14 similar shipments, all labelled "machinery", were sent by Snazel between July and October 2015, with a total of 2,277lbs (1,033kg) of drugs inside.
An NCA spokesman said Maguire held the crates at a storage unit and was caught on CCTV picking up the fourteenth package 10 minutes after it was dropped off.
He was arrested and found to have ecstasy, ketamine and cannabis in labelled bags in a self-storage unit.
The other four were then arrested after analysis of Maguire's phone records in February 2016.
A courier was also charged but was acquitted at trial.
The other sentences were:
Two men who used shipments of lawnmowers to smuggle more than a tonne of ecstasy, cannabis and ketamine into the UK have been jailed for 14 years.