The story goes like this. Rebels in the Indian mutiny, having run out of ammunition but not ingenuity, loaded up their rifles with the pellet-like seeds of cannas instead, thereby giving the plant its common name, Indian shot. Sadly it’s not true, though in a botanical version of ‘Mythbusters’ a Californian botany professor fired canna seeds from 12-gauge shotgun into plywood targets and found many of the seeds were unaltered by the impact! The story is a geographical fail too. The canna is native to the West Indies and tropical America generally, rather than to the East Indies and tropical Asia. The single pellet of poetical truth in the common name is that the brilliant colours of canna do remind you of a vibrant Indian fabric market.
As evidence: currently blooming in my garden is a rich red; a hot pink; the bright orange with dark burgundy foliage called ‘Wyoming’; and a giant orange monster that towers more than 2m high. I also grow a few specifically for their fabulous foliage: an elegant version with purple-edged and striped leaves, which, unfurling, look like calla lilies; ‘Tropicanna’ in lurid sunset tones of purple, orange and pink stripes; and gold and lime striped ‘Bengal Tiger’. This last one looks fantastic backlit but has the downside of insipid orange flowers held on horribly clashing violet-pink stems. I cut them off whenever they appear.
As you can tell from my mix of named and unnamed varieties, cannas are one of those easy-care plants shared anonymously between friends, as well as hunted down through mailorder specialists (try Canna Brae).
It’s estimated there are now several thousand canna cultivars in gardens around the world, which is quite the comeback. In the plant’s 19th century heyday a German catalogue listed 500 varieties and 76 beds of different cannas bloomed to rave reviews at the Chicago World’s Fair of 1893, but when the good taste brigade turned its back on Victorian-era excess cannas were caned. Now the chromatic clamour and tropical exoticism of the canna is back. The dwarf varieties are good in pots, and they go well in the garden with subtropical plants like bananas and gingers and palms, with contrasting foliage plants and with dahlias. That’s a combo made famous by English gardener Christopher Lloyd who gave the English garden world conniptions when he tore out a rose garden at iconic Great Dixter and replaced it with an exotic mix featuring plenty of cannas.
Cannas like lots of sun, are drought-hardy once the clump gets established and look lushly gorgeous when it rains a lot. They respond really well to feeding, but don’t look bad without it. Dead flowers should be picked off the flower spike, and finished spikes trimmed. Don’t cut the whole stem down though, as a new flower spike will likely emerge from the side of the stem. Apart from baby snails chewing holes in the baby leaves, the single canna curse is rust. The powdery orange spots appear on the lower leaves first and quickly spread. Bin badly affected leaves, and control the spread of the fungus by spraying any outbreak, including the mulch surface around the plants, with Ecofungicide.
It’s a small amount of effort for massive effect as it’s not just the colour that appeals but the plant’s explosive growth. The clump shifts from zero to hero as soon as the weather warms, completely changing the sense of volume in the garden. When the cold sets in they start to look a bit shabby. I cut them down to a few centimetres above ground level and mulch with compost and manure. I just get used to the garden without their bulk, height and brilliant flashes of colour when they come booming back again.