When you crave a touch of the exotic in your life, you need cannas. Nothing else gives you that magical combination of lush, tropical foliage and luxuriant flowers. Fortunately they are simple to grow but there are a few tricks to get the best from them.
You can buy them in summer as growing plants but it is cheaper and more satisfying to grow them from dry rhizomes which you can buy now. There are various flower colours and the foliage can be green or purple. All are grown the same way.
When you open the packs you will see a sausage-shaped rhizome and this should be planted, horizontally, just below the soil surface. There may be the remnants of old stems or leaves and these should be uppermost and poking through the compost surface. You can use multipurpose compost and should pot them into the smallest possible pot. This is not always simple because the rhizomes can be quite long. But you should see an old stem and maybe a shoot so you know which way is ‘up’.
You then need to water, sparingly, and keep the pot somewhere warm. A sunny windowsill in the home is suitable. Cannas are tropical and they love heat. It can take a while for dried rhizomes to start to grow so be patient and don’t let the compost get really wet. But there should be signs of growth in a month or so. When they are sprouting strongly and you can see roots growing through the drainage holes in the pot, you can move them into larger pots.
Then you can plant them outside in May. As they grow they spread slightly and send up new shoots and each shoot will produce a stem of flowers.
The key to getting the best of your cannas is to treat them as you would a welcome guest. Shower them with all the things they like. So cannas will grow fastest if the soil is improved with lots of organic matter. They love warmth and sun and they like lots of water and fertiliser. The differences between a canna that is struggling in dry, poor soil and one that is well fed is dramatic. Most disappointments are down to lack of water and fertiliser.
Cannas vary in height and some grow to just 60cm high but others reach 2m when in bloom. Last year I planted one in a pot with a giant zantedeschia, though the canna leaves were a bit hidden! The canna is 2m high.
Once each flower stem has bloomed, cut it off at the base and let the new shoots grow and bloom. Cannas are not reliably hardy in the open garden in winter but they may survive in very mild areas. Otherwise the plants should be dug up in autumn and the rhizomes stored somewhere free from frost. With good cultivation they will increase fast.
Weekly Reminders
Lawn Care: Keep off the lawn if it is frosted. Spike lawns if they are worn and compacted through walking in winter. If the weather is mild and dry give it a light cut – setting the blades to their maximum height.
Digging: Try to get the veg beds dug as soon as possible. You can dig in annual weeds but remove the roots of perennial weeds. Dig in organic matter if you can get some.
Potatoes: Buy your seed potatoes and prepare them for planting by placing them in egg boxes, sprouty end uppermost, to allow the shoots to develop before planting.
Shallots: Always welcome in the kitchen and expensive to buy, shallots are easy to grow in a sunny bed. Buy your bulbs and plant them about 25-30cm apart now. They will be ready to harvest in July.
Perennials: Now is a good time to divide and replant perennials such as asters, day lilies, monardas and phlox.