Evocative is the word that comes to mind when I see canna lilies. I have visions of jungles, plants with giant unfurling leaves, sunshine and bright red, yellow, pink or fiery orange flowers. Hailing from South Africa, New Zealand and tropical and subtropical regions of the Americas, cannas are just one of the exotic flowers from the bottom half of the globe that thrive here.
Cannas require only four hours of full sun to produce nonstop color throughout the summer and often long into fall. Plant them in full sun or partial shade. A bonus for Napa Valley gardeners living in the hills and dales of our county: most deer will leave most canna alone.
Canna comes from the Greek word, kanna, which means reed or grass. The plants are not actually related to lilies at all. Canna is also referred to as Indian shot because of their hard, black, round seed, which is used as a bullet in handmade weapons.
The hosho, a gourd-like Zimbabwean musical instrument, has canna seeds enclosed, another traditional use for this plant. I can attest to the seeds’ pellet-like appearance. They are very round and very hard. I bought seeds and then read the seed packet to discover it would be at least three years until the plants bloomed. Life and my attention span are short. I ordered tubers. They will arrive in February and be verdant and blooming by May.
In many areas of the country, canna lilies need to be dug up in fall and stored through winter before replanting in the spring. We are lucky here. With our comparatively mild winters, and with careful consideration of the planting site, cannas can stay in the ground all year and are considered perennial in Napa Valley. Planting cannas on the south side of a wall, fence or building shields them from cold, harsh winds and provides plenty of sunlight for good tuber formation.
Cannas spread by fattened extensions of the stalk known as rhizomes, which are storehouses of carbohydrates and proteins. The leaves capture those four hours of needed sunlight and, through photosynthesis, convert the light into proteins and carbohydrates that feed and enlarge the rhizomes. The size and health of the rhizomes determine the size and health of the glorious blooms you will reap the following year.
Cannas begin blooming in early summer and are still blooming now in Napa County. One gorgeous display is the eye-catching bed of scarlet cannas in front of Sutter Home Winery as you enter St. Helena from the south. They are stately, magnificent and gloriously red.
Although it is not time to plant cannas now, it is the right time to order for the best selection. Nurseries are filling canna orders now for planting in February and March.
If you already have canna lilies in your garden, let the leaves die back naturally, then cut them at ground level. A little extra mulch will protect your canna rhizomes through the coldest months.
Plan where your canna bed will be in the spring. Cannas are not particularly fussy and can tolerate a wide variety of soil. For the happiest and ultimately showiest plants, provide loose, friable soil amended with manure, compost and high-nitrogen fertilizers.
When it is time to plant, space your rhizomes about 18 inches apart or follow the directions for spacing from the supplier. Plant them about 2 inches deep, placing the rhizomes horizontally with eyes facing up. If the eyes are not obvious to you, they will still find their way to the sun.
When the soils warm up and cannas begin to sprout, give their root areas a good soak once a week. If the weather is especially hot, water every other day.
Cannas have spectacular blooms, but some varieties have even more attention-getting foliage. Their broad leaves remind me of banana plants and come in colors ranging from bright lime- green to blood-red and purple. Leaves can be striped or variegated.
Dwarf cannas produce clumps reaching just a foot or two in height, while giant cannas range from six to eight feet. Other varieties can reach eight to ten feet in height, making a vibrant and dramatic screen. Single plants can be bold focus points.
Local nurseries will have canna rhizomes in the spring, but for the best selection and the opportunity to learn more about cannas, check online sites and order now. Bring a little bit of the tropics to your Mediterranean garden.
Workshop: UC Master Gardeners of Napa County will conduct a workshop on “How to Plan and Plant a Home Vineyard” on Saturday, Jan. 12, from 9 a.m. to 1 p.m., in Yountville. Join our Integrated Grape Team members to learn techniques for planning and planting a home vineyard. The workshop will be held at a new home vineyard planted last year. Learn the necessary planning steps, become familiar with the checklist of activities, methods of determining the proper rootstock, selection of wine grape varietals for specific locations and estimated yield calculations. Review our calendar timeline for planning, site preparation, initial planting and timing of the first harvest for a new home vineyard. Online registration (credit card only); mail-in/walk-in registration (check only or drop off cash payment).