· just now. Report Abuse. Boiled potatoes usually take about 20 minutes, that's if you cut them in half, as for cabbage, cut in half also, it takes about 40 minutes. You don't want to boil cabbage for too long unless you want cabbage mush (or cabbage soup). Same for potatoes, if you want them mashed after being cooked, leave it for about 25 minutes and if you want them to retain the shape, then 20 should do it. Madonna S · 8 years ago. Thumbs up.