Last year, around this time, I posted a blog about taking apart Container Gardens (located under ARCHIVES). Since my gardening clients and friends have asked for information again, I took photos yesterday as I began to break down my containers of canna plants. The canna’s storage roots, called rhizomes, get stored in moist peat in a dark, cool place. You can wait until the first frost to dig them out of your containers. I start mine in early fall, frost or not, when I’m ready and the plants are ready too. Over winter, they stay in a room at about 45-50 degrees F, a lightly ventilated place, where it is not too dry or too cold. The ideal temperature is around 40 degree F. Cannas are propagated by dividing the rhizomes, done in the spring, when I bring them out of storage to grow again each season. These tender tropical perennial plants grow well in our summer climate but can not endure freezing and must be stored during our winter months.
Here are the steps w/photo’s. #1 Cut all stalks about 4″ from base and toss the foliage and stalks. (Tools: Japanese garden knife, loppers, or hand-pruners). #2) Tap the outside walls and sides of the container with a rubber mallet, doing this gently. This helps to loosen up the rootball along the edges.
#3) Lay the container on its side and roll it a bit to loosen more, check base of pot for any roots coming out of drainage holes and remove any anchoring the rootball to the container. (Note: Those containers with liners pop out even easier – A tip from our Container Gardening Parties by me this past spring.)
It may take a few jiggles and wiggles, but eventually the rootball loosens enough. You will notice when it starts happening. The rootballs of my plants were damp so it went easily. It also works easily if the soil has completely dried out, but we got rain this week, so these were wet, but not yet frozen thankfully! Then turn the pot over. With a little more encouragement, dump it onto the ground, in a wheelbarrel (if liftable), or onto a large tarp, blanket, or old cloth if you don’t want a soil mess after. #4) Put the rootball onto a handtruck and move it to the location where you want to keep any remaining soil, like a new planned garden bed area, compost pile, or into the woods. Don’t reuse potting soil next year. It won’t retain its properties well. Remember from our Container Gardening Parties in May, we went over why reusing old potting soil from containers does not lead to success. Reuse it different ways. It is not a loss if you can reuse in your gardens or in your compost pile which I have done many times!
I move mine to a holding area and work there to remove the rhizomes. The handtruck works great. You can also move the pot there first! Duh, which I did later, to do steps #1-2-3-4 for more pots!
#5 ) Then begin the process of removing a big chunk of the soil “from the bottom” part of the rootball. Often you can see where the canna rhizomes are, plus you usually have a general idea of how deep they were planted, so they are not at the very bottom of the container. Work from the bottom up. Cut a big slice off the rootball just to make it easier to get the rhizomes above the base. I use my Japanese garden knife to do this slicing process. Then locate your rhizomes for removal from the soil. In this next photo, I’m showing canna rhizomes (the underground storage stems). See them just below the liner in this pot?
#6) Gently work away the soil around the rhizomes or pull them out. Try to not break or damage the rhizomes. Then cut away the skinny roots from it with “clean” scissors to trim them off (I do this so the little roots won’t rot when stored; just to clean up the rhizomes a bit).
Let the rhizomes sit in the sun to dry just a bit so they are not soaking wet before storing them in peat. My soil was damp yesterday so the rhizomes came out quite clean without much soil attached, so I just used my fingers to take soil off and gently tapped the rhizomes on a log or hard surface to get the soil off the lifted clump of rhizomes. If needed a semi-hard brush can be used to work away any tougher soil, or even a splash of water (but remember, not a good idea to get them too wet). I like the removed rhizomes to be clean, neat, and somewhat dry a little before moving them into a bag for storage with peat, as follows.
#7) After they sit for about an hour or so in the sun, put them in light weight bags (I use bags from the grocery store) and fill them with peat. (If the rhizomes are wet, I don’t bother moistening the peat as often recommended. You can mist the peat very lightly.) I toss the peat around the rhizomes, tie the bag (not tight though) and then put the bag in a cardbox box. #8) Label the box with the plant and date stored.
#9) Put the box in the basement in the coolest spot. Again, you never want them to freeze or get dried out. Either situation ruins them. If it freezes, it rots. If dry, it dies. My place is in the basement, near the basement door, is where it is just cool enough, up off the floor on a bench. Not near a woodstove! This will not work, they will get too warm. You are basicaly letting the rhizomes go dormant until next season. I used old shoe boxes, and some tape to keep the cover closed, but not so tight there is no air. This process has worked successfully for me for years. It is very rewarding to reuse the rhizomes for it saves money each year. In spring, you can cut the rhizomes to container 2-3 ‘eyes’ and start them in sand or potting soil early in the season inside the home if desired.. Then transplant into larger containers or your garden outside after the frost free date when things warm up.
As for the rhizomes, you will see in this photo there are two bulbs like structures attached to the underground storage stem. Don’t cut them apart before storing them. The fleshy parts can get rotted a bit in the storage process if you do because it exposes the softer tissue. Just leave them as is. If you find little bulbs that pull away easily as you take them out of the soil ball, this is okay, but avoid breaking them apart. So in this photo on the left, you can see how it is a stem with the tips pointing up of two new bulbs or eyes that can be separated next year. Cannas are wonderful topical plants with 1 to 5 feet tall stalks, blooming mid to late summer, and showing off large lush tropical leaves in full sun. I also store my elephant ear bulbs and dahlia tuberous roots the same way. Dahlia clumps may be dug in the fall too but before frost and stored at 30-50F and covered with moist vermiculite. The tuberous roots are divided so that each section has at least one shoot. Well, more later on banana plant storage and other favorite tropicals. Thanks, Cathy T