Canna care
By Charles Lillard
Oklahoma County Extension Master Gardener
If you have enjoyed Canna’s this summer, you are wondering, how to take care of them through the winter cold. Looking at my Canna’s in mid-November they looked like dead vegetation. With the right care and a little luck, I will be enjoying them next summer as well.
In northern Oklahoma and all points north, Cannas are usually dug in autumn and stored. However, the further south you go the more likely it is that your Cannas will survive the winter if given a little protection. If you don’t want to take that chance then store the roots (rhizomes) in a cool, moderately dry area. They should be stored so that air can circulate freely. Keep frost from reaching the roots and keep them warm and dry. This is how you generally purchase Cannas. One of the largest producers of Cannas is right here in Oklahoma zone 7. The Horn Canna Farm in Carnegie, Oklahoma ships Canna rhizomes all over the world. They would tell you the safe and sure way of preserving your Cannas from year to year is digging and storing.
My Cannas are in a somewhat protected area. I leave them in the soil where I enjoy them all summer. When the foliage dies back I cut it back although this is not absolutely necessary. Cutting foliage back makes for a more ascetic winter scene. After cutting them back I cover the area with a thick layer of mulch. This seems to work for me. There has been some loss but it is not full scale. If you don’t want to go to the trouble of digging them up and storing them, you might try leaving them in the ground and covering them with mulch. We never know for sure what winter will bring but there is a good chance that the Cannas will come alive again in the spring.
Whether you dig them up or leave them in the ground over the winter, you should give Cannas a try. The foliage alone is reason enough to have them in your landscape. They make a great backdrop for lower growing plants. The flowers can be red, pink, orange, yellow, or white. The foliage has lots of variety from dark green, gold, red, and a variegated black. There is even a variety with bronzy red foliage. They come in dwarf varieties as well as some that reach over 6 feet. During the summer time if the rainfall is less than 1 inch per week they will need some water.
They like full sun but they can get by on less than full sun. They will do well in almost any soil but would prefer a sandy loam. Like most plants they prefer well drained soil. If planting for the first time, plant after all danger of frost is past. This would be about the time you would plant tomatoes. This happens generally in April. Plant rhizomes 12 to 18 inches apart, cover them with two inches of soil. Place the long part of the rhizome horizontally in the ground with the eye up if visible. Canna rhizomes do not have a top or bottom, so don’t worry about placing them upside down. You should water thoroughly after planting. Taller varieties may require staking to continue looking good in the Oklahoma wind.
There are some pests to watch out for. Slugs, snails, spider mites, and caterpillars may be problems. Watch for fungal leaf spot as well. Deer generally are not attracted to canna lilies. They are a tough plant and are worth the effort.
