How to Lift, Dry, Store and Replant Canna Bulbs (Rhizomes)
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Lifting and drying canna bulbs is an important part of growing these showy tropical plants at the cooler end of their hardiness range. Sometimes called canna lilies, cannas (Canna x generalis) grow best in USDA plant hardiness zones 6 to 10, where they are prized for their colorful, orchid-like blooms and large, ornamental leaves.
Cannas are cold sensitive and cannot overwinter outdoors in the colder zones of their range, so lifting and drying the bulbs is vital. The process of lifting, drying and storing canna bulbs is not difficult, but it can be labor intensive and it requires patience.
Tip
Cannas actually grow from underground stem structures called rhizomes, although they are often called bulbs or tubers.
Lifting & Dividing Canna Bulbs
Canna foliage dies back with the first frost at the end of the growing season, at which point the leaves should be cut back to roughly 2 to 4 inches in height. Use sharp pruning shears that have been dipped in household disinfectant or wiped with rubbing alcohol to prevent the spread of disease.
- Use a small spade to dig up canna bulbs because it will be more maneuverable around the rhizomes than a larger shovel. Measure out 1 foot from the outer edge of the canna clump and dig down 6 to 8 inches. Gently pry the canna tubers or rhizomes from the soil, taking care not to break them apart.
- Move the canna rhizomes to a dry location to divide them. Pull apart the rhizomes into small clumps and crumble off any clinging dirt. Each clump should have 3 to 5 rhizomes, each with a few growth points, or "eyes."
Tip
Throw away any canna bulbs that have signs of rot or damage, because they will not store well during the winter months.
Drying & Storing Canna Bulbs
How you dry and store a canna bulb affects how well it will grow when planted in spring. The right storage conditions are important because damp conditions can cause the bulbs to rot.
Drying Canna Bulbs
Canna bulbs must be dried or cured for a few days before storage. Drying will help prevent these tender bulbs from developing mildew and rot, but it is important not to dry out the bulbs too much or they might not sprout the following year.
- Spread the canna bulbs onto a flat surface inside a garage or other open, airy location. Make sure they are in a single layer and not touching each other.
- Dry them for a few days, turning them occasionally to expose every side of the rhizome clump to the air. Throw away any rhizomes that develop moist spots during the drying process.
After a few days, the rhizomes should be dry enough to store well for the winter months. Each rhizome clump should be wrapped in a sheet of newspaper along with a handful of dry medium such as coir, sawdust, peat moss or vermiculite, which will help absorb moisture and keep the bulbs dry.
Storing Canna Bulbs
Set the wrapped canna bulbs in a single layer inside an open crate, cardboard box or cotton tote bag. Place the container in an unheated, dry place where temperatures stay between 40 and 50°F until the following spring. When choosing a storage area, a dark place is best.
Check the bulbs periodically during their long winter storage for signs of rot and to see if they've dried out too much. Throw away any rotten bulbs and mist a fine layer of water over any bulbs that are looking dry and shriveled.
Tip
Paper bags can also be used for storing canna rhizomes—just be sure they are resting on a table when they are stored rather than on the ground so that moisture doesn't soak into the paper.
Replanting Canna Bulbs
Prepare a bed for your canna bulbs next spring after all danger of frost has passed. Wait to replant the bulbs until nighttime temperatures stay reliably above 50°F and the soil is at least 60°F when probed with a thermometer.
- Prepare a bed in your garden that provides full sun or midday shade and shelter from strong wind. Loosen the soil to a depth of 12 inches using a garden fork and mix in 2 to 4 inches of compost.
- Dig 2-inch-deep holes for the rhizomes and space the holes 1 1/2 to 2 feet apart. Settle one rhizome in each hole with the “eye” or growth point pointing up toward the sky. Cover the rhizome with a 2-inch-thick layer of soil and tamp it down.
- Water your canna bulbs deeply immediately after planting them and then do not water again for at least three weeks, or until the bulbs show the first sign of growth.
- Spread a thin layer of mulch around the canna plants, which will help keep the soil moist in warm, dry climates. Use shredded bark or small wood chips.
Caring for Cannas
Cannas require a moderate amount of care if they are grown in a climate where they must be lifted and replanted each year.
- Canna lilies need 1 to 2 inches of water each week during the growing season with a little extra if the plants show signs of wilting during very hot, dry weather. Always check the soil before watering and do not water if it feels very wet from the previous watering.
- Newly planted canna rhizomes do not need spring feeding, if they were planted in an amended bed. However, a light application of fertilizer in late spring and again in mid-summer will help support the plants as they bloom.
- Deadheading, or removing the faded flowers, is an important part of caring for cannas. Transplanted rhizomes take 10 to 12 weeks to bloom and each flower lasts only a few days before it begins to fade. Snipping off the faded flowers will help prolong the bloom.
Cannas can be left in the ground until the first light frost kills the foliage, but don't leave the rhizomes in the garden until the ground freezes or they could be damaged.
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Writer Bio
Sasha Degnan holds a Bachelor of Arts degree in English Literature and Anthropology. Her written work has appeared in both online and print publications. She is a certified Master Gardener and dedicated plant enthusiast with decades of experience growing and propagating native and exotic plant varieties.
