Mentha spicata. Compared to peppermint, spearmint has a less aggressive flavour that has fruity undertones. This mint is easy to grow, and it’s fast, too. In boggy settings it can spread by underground rhizome, but this is easy to control by growing it in containers. The leaves dry well and even fresh they make a nice tea â an even nicer mojito. Sow the seeds indoors a month or two before the last frost date, and transplant out when night time temperatures are steadily above 10Â°C (50Â°F). Ninety days later, expect white to lilac flowers that are both edible and highly attractive to bees. This mint is perennial and hardy to Zone 4.