A good tree cannot bring forth evil fruit, neither can an evil tree bring forth good fruit.
A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit.
A good (healthy) tree cannot bear bad (worthless) fruit, nor can a bad (diseased) tree bear excellent fruit [worthy of admiration].
A good tree can’t produce bad fruit. And a rotten tree can’t produce good fruit.
A good tree is not able to produce evil fruit, and an evil tree is not able to produce good fruit.