Propagating herbs- Root division
Growing herbs by root division in the easiest way to propagate, provided you have a large stock plant that can be spared to do this. The mints are usually increased from root division, as some varieties send out runners which make roots at each leaf node. When dividing a plant, make sure that every piece you take has some rootlets attached to it. When the clump has been separated into a number of suitable pieces, put them into containers with potting soil, and keeps one to use as an extra stock plant that can be divided next year.
If you are interested, and have the time to propagate your own herbs, it can become on absorbing and relaxing hobby and you will suddenly find that you have far more plants than are needed for the garden. It should not be too difficult to sell the surplus stock to nearby nurseries, provided the plants are healthy and have been grown in a conventional plastic pot. No matter how good a plant looks, a potential customer will not buy it if it is growing in a jam tin, or a yoghurt or ice-cream carton! Herbs are also extremely popular on garden stalls at fetes. Presentation is important here too and a fair price may be charged for them if they look professional. A gift of an herb plant to friends and family is always welcome.