and under communism, if they were caught growing and withholding food for themselves without the knowledge of the state, they'd get gulag'd
no, nothing happened to them. the communist state doesn't care if you have a small backyard vegetable garden, plus they lived in a rural area where there wasn't super-heavy ussr influence.
that's the difference between a negligent dictatorship and a genocidal dictatorship. one simply doesn't care, and the other "cares" far too much.
keep in mind this was not deep central USSR, this was communist poland as occupied by the USSR. it did suck bad but they did not round up people for something as insignificant as having a backyard garden.