[header] How to grow mint [title] Take a cutting from a pre-existing mint plant. [step] Mint is difficult to grow from seed, and it is virtually impossible for some varieties, like peppermint. Cut a 4 inch (10 cm) sprig about ½ inch (1 cm) above a junction to allow new branches to grow in its place. 
The sprig does not need to have many leaves, and almost any sprig will do. Place the sprig in a glass of water, and remove any leaves that fall below the water line.