Cannas are a beautiful old Victorian plant with bold color flowers, and gorgeous big tropical looking foliage. They are perennials so you don’t have to replant them and are very popular throughout the country. They have been used less in California for a few reasons and John Schoustra of Greenwood Day Lily Gardens outlines a few here and some solutions for you.
Cannas like warm nights. Although our climate is warmer year round, Eastern nights in May or June are warmer and more humid. Our cold spring nights slow the emergence of cannas from their semi-dormant winter state. For best results, protect cannas from cool coastal breezes and plant them where pavement or masonry walls will re-radiate heat at night.
Cannas can go dormant or look straggly. The key to canna vigor and appearance in our climate is a simple grooming technique. After the first cluster of blooms on a cane has finished, cut that cane back to the ground. With secondary bloom bud showing, it is tempting to remove just the spent blooms. If this is done, over time the plant habit will become more and more sprawling, with spindly new canes.
Canna viruses. A complex of at least four viruses together cause slow spring growth, reduced vigor, streaky foliage and misshapen blooms. Our mild winters allow cannas to avoid full dormancy, which allows the viruses to over winter. The viruses are spread by cutting tools and insects, so most cannas in California are infected. Virus free plants are usually infected within a year. Some of the varieties that suffer worst from virus symptoms include: ‘Lucifer’, ‘Technicolor’ (Pink Sunburst), ‘Wisley Dwarf’, ‘Panache’ and ‘Ehemanni’. The key is to plant vigorous virus-resistant cultivars, site and prune them properly.
(Taken directly from Greenwood Reference Guide – courtesy of John Schoustra)
Once your plants are well established, try watering them deeply once a week; you may even be able to go few weeks between. Mulch will help to hold in water and will provide your cannas with nutrients. You will likely have to water generously in summer, however you can usually cut back in September.
The Cannas that are offered at Greenwood Day Lily Gardens are primarily virus resistant; to have the best chances of virus free Cannas, try John’s varieties.
So many people are going to low water and native plants and most people interpret these to be high water plants, but actually they can take deep infrequent watering and be very happy. They can also be greedy and will happily accept a lot of water and fertilizer if you give it to them. So… If you have a spot in your yard where the water is pooling, neighbors over watering into your yard, or just a low; spot pop a few cannas in. The cannas will drink up that water and filter pollutants out to boot! Before popping in those cannas make sure that you check your irrigation, you might have a sprinkler or timer problem and that should be fixed.
Cannas like humidity and don’t mind a splash of chlorine, so they are great near pools; I like to keep them contained within hardscape because they tend to take over the area that they live in.
Cannas may be used to add a tropical look to your garden. They have the look of a tropical plant without a lot of the negatives; they can take the sun and heat where others may not. Cannas are a beautiful addition to Hibiscus, Birds of Paradise and of course Day Lilies for that tropical poolside oasis.
Cannas are an old world looking plant, one that could easily remind you of simpler times and your grandmother’s garden. A few bright cannas at the back of a bed with some Grandma’s Purple Flag Iris are a stunning contrast… what could be better?
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