I first saw it in my local branch of Marks & Spencer's in 2006 and was attracted to its unusual appearance. It stood out a mile among the boring red homogenised tomatoes ... a deep red rounded fruit with a glossy skin and dark olive green stripes. I do commend M&S for their commitment to trying out new and unusual things, and this is undoubtedly the most interesting tomato I've ever seen on a supermarket shelf. I couldn't resist buying a punnet of them, and they tasted pretty good. Not the best I've ever had, but good enough that I wanted to try growing it. Commercially grown fruit is never in its prime, as it's usually picked prematurely and chilled to within an inch of its life. So if a supermarket tomato tastes good, it should taste better when home grown. The shop-bought fruit had been grown in Kent, so obviously could cope with the British climate.

Of course the down side of saving seed from supermarket fruit is that you don't have any idea whether or not it's an F1 hybrid. If it is, it won't come true from seed. Not that that's necessarily a problem. Last time I took a fancy to a "Marks & Spencer's exclusive" tomato, Pink Jester, it did turn out to be an F1 hybrid and there was a lot of variability in the seeds I saved. Some were very like the original though, and others were slightly different in shape but had an even better flavour. So I've been happily growing out the F3 lines ever since, and I'm glad I saved seed from it when I did because it soon vanished from the shops. I expected much the same situation with Green Tiger ... hoping it might be an open-pollinated variety which would breed true, but prepared for the likelihood that I'd get a weird mish-mash of types and would have to select the ones I liked.

Flowers are small and star-shaped with a slight dark blush on the petals. They grow in short trusses with chunky peduncles bent at rightangles. The calyx is a dark green star, broad and chunky.

Young fruits are a bright emerald green, shiny and spherical. The stripes don't start to develop until they're close to reaching full size. The earliest fruits are about the size of a golf ball, but later ones are more cherry tomato sized. As they near ripeness the green stripes darken, and the rest of the fruit takes on an orangey-brown hue, eventually ripening to a deep dark burgundy red with a more bright and intense red at the top of the fruit (hidden under the calyx, so you only see it after picking). The green stripes stay green, and are kind of mottled. It's an unusually dark green, like a very dark olive.

The surface of the skin is very shiny and attractive. Like most commercial varieties, it has quite a thick skin and stays very firm even at full ripeness. This is what commercial growers want, to enable it to withstand packing and handling. The advantage it has to gardeners is that the fruits are fairly resistant to splitting.

I'm still curious about where this tomato comes from. It was apparently introduced by Bernard Sparkes, a farmer in West Lancashire, but it's not clear whether he bred it himself or brought it in from elsewhere. Marks & Spencer's are marketing it as their own "exclusive" variety, but I wonder what that actually means. Did they commission it? Or does "exclusive" simply mean that they're the only store currently selling it? Is Green Tiger its real name, or just for marketing purposes? I'm a little sceptical about the names and claims made by supermarkets. But certainly this variety doesn't seem to be available in garden centres or seed catalogues. If it really is an exclusive it may well have Plant Breeder's Rights on it, in which case tough shit because it's already doing the rounds at informal seed swaps across the UK.

I'd definitely recommend this. Whether you pick it up through a seed swap or scrape some seeds out of a supermarket fruit (not sure if they're still selling it, and if they are it's only a limited season) it's well worth giving it a go.

Photo: Unripe fruits, beautiful bright green and smooth and round as a snooker ball.