Indian summer to continue

BRITAIN can look forward to basking in yet more glorious sunshine as our Indian summer looks set to carry on into next month.

But let’s hope the Met Office has got its forecast right this time after a washout summer. Forecasters there faced a storm of criticism for a long range forecast earlier this year of a “barbecue summer” that never happened.

The Met Office also says that the rest of this month will see a north-south split, with the south staying relatively dry and the north becoming wetter.

Forecasters Positive Weather Solutions, which uses comparisons between current trends and past weather patterns, agrees that the rest of September will be “dry with sunshine”. And it says in the south this should continue into October.

Its forecaster Jonathan Powell said: “Bar the odd rainy day, the remainder of September will be dry with lengthy periods of sunshine. “For the south of the UK, October will start the same way – dry, sunny, but rather chilly by night.”

Despite what seemed like washout weather, it was revealed yesterday that parts of the UK have had their driest summer since 2000, with Kent getting 77 per cent of its normal rainfall between June and August.

By mid-September, southern England and East Anglia had just 24 per cent of the rainfall expected for the whole month.

The only bad news there as far as Cannas are concerned is the chilly nights, so it's time to start watching out for night-time temperatures again, and to start clearing the last of the food crops out of the poly-tunnels. There is still courgettes, potatoes, spinach, beetroot, carrots, water melons, tomatoes, chilli's and other peppers to get picked, lifted and composted before fertilizing the soil again and rotavating ready for when the Cannas need to start their hibernation.

The first shoots of spring?

It may look inconsequential to most people, but the photo above shows the first Canna shoot of the year for us at Claines Canna. The plants are all in the soil inside poly tunnels, where they have been since the frosts cut down the summers top growth last October.

The weather has now turned and the first signs of spring can be seen; of course we still have a way to go before we can say that winter is truly over, but the winter blues have now left the writer and we can look forward to better things ahead.

One of the advantages in using a polytunnel is that the specially formulated plastic covering traps heat from the sun and the daytime temperatures in the tunnel will be at least double those shown on the graph above. This has the effect of heating the soil during the day and when the outside temperatures drop overnight that stored heat will double the tunnels' overnight temperatures, as shown above.

If a Canna enthusiast has just a few specimens then the time honoured advice to store in a greenhouse or garage is still the most appropriate, but for anyone with a large number of plants to over-winter I would suggest that they consider growing in the ground inside a poly tunnel as a serious, proven, and practical approach.

Growing more species specimens

Well, at long last we have finished transplanting the collection outdoors, and the watering system is installed. However, still no time to relax as we are erecting another polytunnel, which will ensure that all our Cannas can be grown indoors, and in the ground over the winter.

As Cannas never become dormant, unlike bulbs, the cultivars thrive best if kept growing slowly through the winter. It is amazing how much growth the healthier ones put on during late winter and early spring.

Altogether we lost about 20 cultivars, which were mostly planted around the edges of the largest of our polytunnels. The use of another tunnel will mean that we can leave a 60cm (2 foot) empty space around the inside next year.

We have not solved the problem of the dying species. The only species specimens to survive the winter were the indica, patens, discolor, and glauca specimens. Experience has shown that the rest are too delicate to withstand any frost at all, and we will have to look at other ways of over-wintering them.

It may be that we stop trying to over-winter them and just rely on growing them as annuals from seed. A correspondant, living in the Dominican Republic and enjoying tropical weather, confided that he only grows his species plants for two years, and then he replaces them with new seed-grown specimens. There they grow 52 weeks of the year quite naturally. As species grow true-to-type, there is no problem with growing them from seed.

However, one of our Canna wild species is totally sterile. Canna discolor is sterile for both seed and pollen, and as we have to rely on the rhizomes thriving, we intend to grow several specimens in the future, and over-winter them in different places, to try and guarantee their survival. It took many years of trying to acquire the genuine C. discolor, and we don't want to loose it. In addition, next winter we will be making it available to enthusiasts, so providing some insurance for the future.