Dividing Iris

Credit: Terry Guscott

Whether you are trying to increase their quantity or improve their general health, irises benefit from consistent divisions every few years. Iris vigour tends to wane over time if not divided.

The divisions are best done in early spring or fall when cool damp weather conditions favour their success. It is not advisable to divide an iris that is actively blooming or about to bloom. Irises can be divided right after flowering, but the warm, dry weather of summer can be problematic unless you pay extra attention to watering. The only tools required are a good sharp digging shovel and a pair of secateurs. Dig up the iris that is to be divided. Use the shovel to split the iris into the desired number of plants. With your secateurs, trim away any excess roots or weak tissue. Move the division to a new location, planting the rhizome to the correct depth. Firm the iris into position, removing all air pockets. Water the spot, and you’re done.