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Credit: QFB Gardening -
Credit: American Meadows
Growing Tips: Canna Lillies
OVERVIEW
Despite their name, canna lilies are not related to true lilies. They are more closely related to bananas and ginger. Several species are actually native to the US.
Cannas can be both focal points and stylish accents. Use them to bring structure as a tall border or to add depth to narrow spaces. They add a colorful splash to garden borders and poolside plantings, bring a tropical touch to water features, and thrive in boggy areas.
SITE SELECTION
- Cannas need wet soil. If the soil doesn’t remain moist, provide a good soaking once a week and every other day during the hottest weeks of summer—water freely in dry spells.
- Maintain a thin layer of mulch to help retain moisture.
PLANTING
- Plant in the spring when soil temperatures have warmed to 60 degrees F; cannas are sensitive to cold temperatures.
- In cold, short-season areas, start canna rhizomes in pots indoors or in a greenhouse, ready to transplant outdoors at the right time.
- Plant horizontally with the eyes facing up, and cover with 4" of soil.
- Dig a hole in fertile soil with a good amount of organic matter and plant your rhizome with the pointy growing tips (eyes) facing upward; cover with 4" of soil.
- Water in well at planting, then wait for shoots to appear (which may take up to 2 weeks) to resume watering consistently.
- Space rhizomes 1-1/2 to 2 feet apart to give cannas enough room. Containers need to be at least 18 inches in diameter (per rhizome).
- Full foliage color develops when days are warmer (59ºF or more). Blooms should appear in 10 to 12 weeks.
SPRING/SUMMER CARE
- Remove spent blooms regularly to encourage continuous flowering
- If provided with consistent water, good fertility, and deadheaded regularly, Cannas will thrive, grow strong and tall without requiring staking, and bloom until frost.
- Stake tall varieties, if necessary.
- Where the soil is fertile, fertilizer is optional. However, canna are big eaters and would benefit from slow-release fertilizer at planting and twice during the growing season.
- Fish emulsion fertilizer, which is a little higher in nitrogen, is a beneficial organic alternative. Higher nitrogen fertilizers tend to increase canna height. Rose or tomato food products are also suitable.
- Deadhead to promote more blooms using garden pruners or scissors (not your fingers).
FALL/WINTER CARE
- After the entire plant has been deadheaded several times and with flowers no longer forthcoming, cut the flower stem back to the foliage.
- Only at the end of the growing season should you cut the plant down to around 6 inches off the ground.
- Bring cannas grown in pots indoors into a garage or basement for winter. Keep them dry until spring’s nighttime temperatures are consistently above 50°F., typically after the tulips have bloomed in northern areas. Only then move them outside for the summer.
- Dig up (lift) in-ground cannas in the fall and bring them inside for the winter. After cutting the canna back (as above), dig out the rhizome with a shovel. Avoid damaging the rhizome by digging about 1 foot away from the stem. With your hands, gently loosen the soil and lift out the clump. Shake off the soil and cut off any foliage. Divide clumps into 3 to 5 rhizomes, each with eyes.
OTHER CARE TIPS
- Store cannas over the winter in a dry place where the temperature will not drop below 40ºF. Often, this is a basement, attic, or garage. Check the rhizomes a couple of times over the winter to make sure that they don’t dry out. Mist with a bit of water, as needed. If you find rot, strip it away or discard the entire rhizome.