To harvest mint, pick leaves just before flowering or cut the stems to keep from flowering. Plants will often grow new branches below the cut.
Mint definitely spreads quickly otherwise. If this is fine with you, let it flower. If you have different mint varieties, however, and you want to keep them true, you need to remove all flowering stems to avoid cross pollination.
To harvest mint, pick leaves just before flowering or cut the stems to keep from flowering. Plants will often grow new branches below the cut.
Mint definitely spreads quickly otherwise. If this is fine with you, let it flower. If you have different mint varieties, however, and you want to keep them true, you need to remove all flowering stems to avoid cross pollination.