Just when I can’t bear another weekend indoors, it’s time to pot up the cannas. Spring’s first gardening chore! If you’ve saved a clump or two of cannas, try my technique.
You can plant rhizomes right in the ground, but I find it more practical to start them in pots first. By the time they’re ready to burst out of the pots, it’s time to plant them outdoors — or give them away to gardening friends.
Keep in mind that you’ll need a sunny place for your new plants. I put them in my greenhouse, which keeps them safe from frost and provides plenty of warmth and sun. You could also set them in a sunny, south-facing window, moving them outdoors when frost-free weather arrives.
Start by shaking the soil from the clumps. I keep the clumps barely moist through the winter, so the soil is usually quite dry. You can replant the whole clump, but I like to divide it so I get more plants. Inspect the thick rhizomes, looking for healthy sections. Try to get sections that have two strong “eyes” (where new growth is emerging) and no sign of rot. Once you’ve isolated a section, cut it from the main clump with a knife or a sharp pruners. Get as many good sections as you can from each clump.
Once your sections are cut, gather some clean nursery pots. In the fall, I try to save black pots that come with mums. Any 8″ (or larger) pot will do, but the mum pots are usually wider, so they can accommodate the rigid canna rhizomes.
Plant the rhizomes about 1-2″ deep, using fresh potting soil, such as Transplant Mix. If space is tight, it’s OK to plant the rhizomes at an angle. They don’t seem to mind being cramped in the pot.
Water the pots well and put them in your sunniest location. Water sparingly until you see new growth because too much water can trigger rot. Once fresh green leaves appear, start fertilizing with a water-soluble fertilizer. Cannas benefit from regular feeding throughout the growing season.