This week, full of the joys of spring, we will not be lunching on the lawn, but instead discussing how to turn your lawn into lunch. The days of gratuitous grass are over. Indeed, in a few years, lawns will be horribly unfashionable, as they were in the time before Capability Brown.

You may have noticed recent headlines about the looming global food crisis, which is looming a great deal more menacingly in hot, faraway places of which we know little. You may have always giggled at hairy people wearing T-shirts with the slogan “Think globally, act locally”, but it seems silly not to at least try. So I propose that those of you with excess green sward should do your tiny bit to avert the food crisis by growing your own.

I tried to find out how many millions of acres of lawn there were in Britain, but no one seemed to know. All I can tell you is there’s a lot of grass about. You see it on street corners everywhere. But in America, where the food-not-lawns movement is growing daily, domestic grass is the country’s biggest and most useless crop – all 32 million acid-green acres of it.

Of course, there’s nothing wrong with a lawn as a play space – we want more of those, even if they tend to become soups of mud. But maintaining a purely ornamental lawn is a fruitless (and veg-less) activity which should be discouraged.

In many ways vegetables are less work than grass: put in potatoes in late March, earth them up, hoe them occasionally and eat them all summer. The serious groundsman, however, believes in manicuring his lawn. He will be mowing his grass fortnightly with a petrol-guzzling or electric mower, strimming the edges, watering prodigiously with a sprinkler, scattering herbicides and pesticides, and possibly purchasing (I see an offer in the paper) an electric, £139 “lawn scarifier and aerator for the extra-fast removal of unwanted moss, debris and thatch”.

This lawn, this sterile monoculture which discourages almost all wildlife, began as a symbol of wealth and grandeur on the English estate – land was so prolific there was no need to sully it with vegetables. That was relegated below stairs, to the servants in the kitchen garden, or the serfs on the farm.

Now, however, with the prices of staple foods up by 40 per cent, tackling the problem in a small, local way makes people feel momentarily empowered while the world climate’s hot flushes or flash floods signal the decline of fertility.

I must confess here that along with my allotment, I still have a tiny unproductive lawn at home, 3m x 4m of patchy, shaded, yellowing grass, covered in hummocks and holes where the dog has been digging deep for kangaroos. And my grass is so bald that only a comb-over will work. I have tried, but no veg will grow in these shady, dog-deranged conditions, except in pots.

If you have a dog-free green zone, you can turn it from a lawn into an “edible estate” – the fashionable American term, which sounds much grander than a veg plot. If you are worried by the ugliness of bare soil in winter, you can scatter a green “manure” like white mustard or clover in autumn, and dig in the plants as instant fertiliser in spring. What’s not to like?

The Americans are also very keen on “asphalt gardening” in cities – reclaiming empty lots or disused parking spaces, placing wooden raised beds on them, and growing tomatoes and pumpkins beneath sheltered walls in the hot urban sun. The earth soaks up run-off water that would otherwise overload the sewers in storms, and the green softens the hardness of the concrete landscape.

Here in Britain, the guerrilla gardening movement does a bit of that, rescuing city roundabouts from desolation, but the emphasis is more on flowers than food. You can be sure that if you planted vegetables in public places, hoodies would hit your carrots hard at night, but possibly they need the vitamins most.

My own asphalt gardening plans are progressing: I have staked out a sad, tarmac-covered site, acquired three drawers from an abandoned chest as ready-made raised beds, and now I am casually patrolling the streets in the people carrier, looking for a skip filled with soil dug from a basement conversion so I can steal some. A little compost, two packets of marigold and carrot seeds (the smell of the marigolds keeps off carrot fly), and you have a cheap and cheerful mini-public park.

So toss away your lawnmowers and pick up a spade: be the proud owner of an edible estate. And if veg are not your bag, you could get a couple of sheep as living lawnmowers for your garden. All the best estates have a few judiciously placed sheep or cows pour animer le paysage – to make the landscape more entertaining to the eye. And when you get bored of counting your sheep, you can eat them.

kate.muir@thetimes.co.uk

Times recommends

• What took place in 2010...
• Can you really cure a hangover?
• Video: How to do glamorous smoky eyes