Victoria Summerley: Town Life

Everyone's gone bananas. Once upon a time, the gardens round my way might have boasted the odd ancient apple or pear tree. Now we grow fruit that is more usually associated with the Windward Islands than with Wandsworth.

The appeal is obvious. Bananas are fantastic architectural plants, ideal for making an impact on a minimalist patio, or for conjuring up memories of exotic holidays on tropical shores. They suit the sunny south-east; indeed, at Clare College, Cambridge, the head gardener has reported that his banana plants have produced fruit for the first time, a phenomenon attributed to global warming and this summer's hot weather.

I'm not sure what variety the Clare College bananas are, but given that they are growing in the college grounds and not under glass, my guess is that they are Musa basjoo, a hardy variety that doesn't produce edible bananas. Still, I can understand the head gardener's excitement, because as far as I'm concerned, bananas bring out the latent prize-marrow, size-matters type of gardener that lurks deep in the heart of anyone with even the smallest horticultural pretensions.

One of the most fascinating things about them is the speed at which they grow. No sooner has one huge paddle-shaped leaf stretched out to its full length, than the next one coyly uncurls from the stem. At this time of year, given the right conditions, they'll grow a leaf a week. Given that a leaf can measure up to six feet long - depending on the size of the plant - that's a lot of banana.

Walk into any decent garden centre in London and you'll find at least two varieties on sale, probably more - usually Musa basjoo, or Ensete ventricosum, the so-called Abyssinian banana (not so hardy but with wonderful red stems) and Dwarf Cavendish, which will, in theory, produce edible fruit (if you keep it in a conservatory or greenhouse).

Dwarf Cavendish is the pygmy relation of the Cavendish banana which currently supplies the world with most of the yellow edible variety.

And while we're on the subject of edible bananas, guess which country produces most in the world? Costa Rica? Brazil? Nope, it's India, which produces 23 per cent of the worldwide crop (though the biggest exporters are in Latin America). This is appropriate, given that bananas originate from Asia. It was the Portuguese who took them to the Caribbean and Central America at the beginning of the 16th century, while Arab merchants introduced them to Africa.

Strictly speaking, the banana is not a tree but a herb, in that it has stems rather than a trunk and dies down each winter. It's the largest plant on the planet that doesn't have a trunk, in fact. Although it is an exotic, and you'll see it sold alongside palms and yuccas, the banana is not really drought-tolerant. Those big leaves need lots of water, so be prepared to scurry back and forth with a watering can if you live in a hosepipe-ban zone. The odd bucket of compost helps too.

The leaves also start to look pretty tatty after a couple of seasons, so be ruthless and chop them down at the beginning of the winter. (This also makes it easier to protect the plant from frost with a blanket of fleece or straw.)

The tendency to fray into strips may be unsightly, but it's a safety feature, designed to protect the plant from being toppled by hurricanes. Clever, huh?

I got my Musa basjoo at RHS Wisley, but I've seen them on sale in Homebase and B&Q. My local Homebase seems to be particularly drought-aware and is full of prickly plants that won't die if dry.

The local B&Q, on the other hand, doesn't seem to know there's a water shortage in London.

When I visited the other day, an assistant was watering a shelf unit full of bedding plants with a hosepipe. The end of the hosepipe attached to the tap was leaking, creating vast puddles. Meanwhile, the sprinkler end was being applied with great enthusiasm to the bedding plants, resulting in Niagara-like torrents cascading down from the shelves to join the flood caused by the leak. Now that's what I call bananas.