Domenico Masciopinto, 35, was sentenced to 14 years in 2012 for drug-dealing.
From prison he told his now estranged wife Giulia Masciopinto, 37, to unearth cash buried in their Bedford garden.
She has been jailed for nine months. Her mother Caterina De Filippo, 58, and sister Palma De Filippo, 28, were given 12-month sentences for helping her.
Domenico Masciopinto was sentenced to 22 months, after admitting concealing criminal property, to run consecutively to his 14-year term.
His wife also pleaded guilty to the charge, but the De Filippos, who she enlisted but who denied the accusations, were found guilty last month.
Judge Kristina Montgomery QC, sitting at Amersham Law Courts for Aylesbury Crown Court, said the Masciopintos would have been jailed for longer if they had not admitted the crime.
Cash was found by police stuffed around the Bedford homes of Giulia Masciopinto, in Redhall Close, and her mother's in Harrowden Road, in March 2013.
Officers were alerted by Masciopinto's recorded prison calls to his wife, as he feared the buried cash would perish as it was not in watertight containers.
A holdall containing £237,000 was discovered, while thousands of pounds were also found in a handbag, plastic bag and foil-wrapped bundles. Other money had been paid into bank accounts.
Palma De Filippo, of High St, Acton, west London, helped by hiding some of the cash in her car boot and laundering it.
Det Insp Pushpa Guild, of Bedfordshire Police, called it a "sophisticated attempt" to hide criminal proceeds.
Police said some seized cash would go towards paying a £121,736 confiscation order, made after Masciopinto was jailed three years ago.
However, some notes were unusable as they had turned mouldy due to the way they were stashed.
The wife of a jailed drugs ring boss who dug up his £270,000 cash stockpile to help launder it has been jailed, along with her mother and sister.