Canna lilies are beautiful plants that brighten up any garden with a variety of colors and sizes. In regions where the winters are too harsh for these plants, it is necessary to dig them up and store them somewhere safe from the cold. In regions where this isn't necessary, it is still important to dig them up from time to time, to divide them. If left alone, canna lilies will get too dense and begin competing for nutrients and water. The rhizomes, large tuberous root structure, can be broken into pieces, as long as there is a section of root and a stem attached to each rhizome.
Step 1 - Time your Dig
The best time to dig up your canna lilies is when they aren't blooming. If you store your bulbs in the winter, then divide when you dig them up for storage. If you leave your bulbs in the ground all year round, dig them up in the fall or early spring every three or four years.
Step 2 - Cut off the Greenery
Canna lilies will quickly regrow any greenery you remove. You can limit yourself to trimming off any leaves that look damaged or dead. However, removing the leaves allows the rhizomes to focus on establishing its roots before worrying about the leaves. Just use a pair of clean scissors to trim off the leaves a few inches above the soil.
Step 3 - Dig up Your Cannas
If the soil is loose, it may be possible to reach in with your hands and work the canna lily rhizomes loose with your fingers. If the soil is packed, use a shovel, beginning to dig at a distance to keep from damaging the root structure. Work the entire clump loose until you can lift it all out of the soil and examine the roots.
Step 4 - Remove the Soil
Work the clumped soil off the root structures. Try not to tear the roots off. If you do it shouldn't kill the plants. It might just weaken the plant in the short term. You can rinse the roots with water once you work a large portion of the soil off. You want to be able to see where the sections of the rhizomes can be separated.
Step 5 - Divide the Rhizomes
Separate sections of the rhizome. You can break them apart in your hands, cut them apart with a clean knife, or attack the clump with a shovel or spade. The important part is to ensure each part has a stem and some root attached. Cannas like being a bit crowded, so feel free to leave it in larger chunks with more than one stem.
Step 6 - Replant the Rhizomes
Leave the rhizomes out for around 24 hours to let the cuts dry and scab over. In this time you can also distribute spare rhizomes to friends and family. Plant them in a hole with the stem upward. Ensure the average soil depth over the rhizome is three inches.