Digging and Storing Canna

I am offering this because I see postings about canna that don’t really go into digging and storing tubers in any detail (although there must be – so feel free to point to them should you respond), and also because canna can be dug and stored up to a hard freeze, followed by freezing temperatures.

DIGGING
Best done at first frost, or just before while weather can be more tolerable.
Dig (or I should say “pry”) the tubers out of the ground with a garden fork (the tubers are actually underground stems with roots emerging from beneath and stalks from above) trying not to break them apart – sometimes difficult to do.

PREPARING FOR STORAGE
1. Wash away all dirt
2. Cut away and discard rotted or infected parts
3. Cut back all roots as well as stalks
4. Divide into at least one eyed tubers – making a clean cut
5. Dip in a water/fungicide solution (captan will work)
6. Allow to dry

STORING
Ideal conditions:
1. temperature maintained between 40 and 45 degrees F
2. area is dry
3. there is air circulation
4. containers and packing media allow ventilation
STORAGE CONTAINMENT AND MEDIA
The best containers are crates; cardboard boxes with holes punched in
the sides; onion, potato, or burlap sacks; or plastic bags with holes punched in the sides.

MEDIA
Can be wood straw, unmilled sphagnum moss, styrofoam
peanut packing medium (perhaps the best of all because it is sterile, allows air
pockets, and is light weight and can be reused year after year), shredded newspaper, or individually wrapped in newspaper. The important points in this regard is that the packing media must be dry, does not pack to prohibit air ventilation, and must be free of micro-organisms.
Note: Peat moss is often advocated as a packing medium, but my experience, and others I have spoken with, have found that even under the best storage conditions there will likely be some spoilage, and even the tubers that survive are likely to be at least blackened or atrophied to some degree.

WHERE TO STORE
Most gardeners rely on a crawl space or basement – given suitable temp. and moisture conditions. The best place is a root cellar. But who has one of those?

RODENT PRECAUTION
I have not heard of mice or moles eating canna tubers but a way to avoid this is to
toss a few packets of mice poison in the vicinity – at least to keep mice
from making off with the packing medium to build nests or even nest in the containers.

I usually store about six crates per year with 12-30 tubers each depending on size and get a 99-100 success rate of firm white/pinkish/maroon tubers that look as good as the day I dug them up.
Then its time to dole them out to friends and neighbors and package and mail 20 per to my daughters in OH, CO, and WI -- leaving a few for me to plant in border backgrounds or in focal places in the landscape.

Incidently, as mentioned in various DG forums, canna can be left in the ground to come back next season given the proper micro-climate, even in some freezing zones. And, of course, they are quite easy to propagate from seeds, and also, they can be very attractive potted esp. in whiskey half barrels.

Thanks so much for the details. This is my first year for digging cannas. I just knocked the dirt off, did not wash them. I put them in bushel baskets in the basement. That's what my MIL did so I did the same. A couple of questions I have... Must they be packed in a medium? What purpose does the medium serve?

kooger

The medium serves two purposes:
1. It acts as a temperature moderator should the temperature range I mentioned abruptly vary higher or lower (much like mulch in your garden).
2. It helps maintain the moisture level contained in the tubers when you first stored them.

However, the storage conditions you and your MIL have may be so ideal that the medium is unnecessary. This is the case with many nurseries that have temperature and moisture controlled facilities to over-winter tubers for spring shippage. However, they usually package the tubers in unshredded sphagnum moss or wood shavings for shipping and sale.

The most important aspect of storage is temperature, dryness, and air circulation. The medium and fungicide are just added precautions.
I have successfully stored canna without a medium, but loosely covered the containers with house insulation.

One last note, canna tubers are loaded with carbohydrates. It is surprising how seemingly atrophied tubers will spring to life when replanted in the spring – but not as readily, nor as hardily as the healthily carried-over ones. It is not unusual to have first rate wintered-over canna (non-dwarfed varieties) grow ten feet tall because of the great start they get. This, of course, assumes proper soil, irrigation, and sunlight conditions.

Good luck. The proof is in the pudding.

shakemh

Thanks so very much. I'm gonna print those instructions and file them for future reference.

I can atttest to the atrophied tubers springing to life. I received a bag at the RU (part of the cleanup crew) and put them in the garage and promptly forgot about them. I think it was about 2 months later that I found them and planted them. I couldn't believe any were viable but I felt so bad for forgetting them that I just stuck them in the ground. First there were just 3 or 4 that grew, but when they were a couple feet tall already, I noticed a couple more starting and a couple more and that bunch of tubers produced a 3/4 bushel full of big fat pink tubers. WOW! I am amazed!!! (and thrilled!)