Nepeta, also known as catmint, can be propagated by taking cuttings or dividing the plant

Taking cuttings: In late spring or early summer, cut 4–6 inch stems from a healthy plant 

Remove the bottom half of the leaves  Cut the stem at a slight angle just below a leaf node  Dip the cut end in rooting hormone  Place the cutting in a jar of water or a pot of moist potting mix  Put the cuttings in a bright location out of direct sunlight  Keep the soil moist or change the water every few days  After about two weeks, new growth should appear  Roots should form in the water, or you can transplant the cutting into a pot of soil 

Dividing the plant 

  1. Dig around the plant to separate it into sections
  2. Place each section in its own pot

Tips

To reduce water loss, remove the bottom leaves or cut large leaves in half 

To prevent mold, keep the air moving and remove any affected areas  To prevent bacterial infections, keep everything clean  Place the cuttings in a warm, humid environment to encourage rooting