Fleshy-rooted bulbous plants require division when their multi-plant colonies become crowded. In general, lift and divide deciduous bulbs after flowering has finished and their foliage begins to wither. Divide evergreen bulbs in autumn or early spring. Divide bearded iris at early to midsummer. Gather a sharp, long-bladed knife, a shovel, two hand forks, gloves and a tarp, then follow the easy steps shown in the pictures and described in their captions.
Dividing Tubers and Rhizomes - Step 1
Carefully using a shovel, vertically cut the soil around the bulb colony, about 6-8 inches from the outermost stems.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Dividing Tubers and Rhizomes - Step 2
Working with the shovel in a circular pattern outside the cut, remove soil with angled cuts to gain access to the soil beneath the colony.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Dividing Tubers and Rhizomes - Step 3
Carefully drive the shovel under the colony, freeing and lifting it. Set it onto a tarp.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Dividing Tubers and Rhizomes - Step 4
Use two hand forks in opposition to one another, prying the colony apart and working between the plants.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Dividing Tubers and Rhizomes - Step 5
If necessary, carefully use a sharp knife to cut between the plants.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Dividing Tubers and Rhizomes - Step 6
Discard the oldest, central plants. Replant divided sets at the spacing recommended for the particular species.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
