Where do you want your children to spend August? Alone at home? Under your feet? Or would you consider sending them away to live with a convalescent military historian, a jobbing journalist and a fluctuating number of untrained assistants?

Back in the l950s, when country air and frequent roast beef dinners were seen as the simple key to holiday happiness, that is just what many parents did. I know, because mine was one of the households the young visitors invaded. At the end of each school term I braced myself for the arrival of up to 30 temporary siblings. I already had three sisters and a brother. Our convalescent father was an invalid. Our big-hearted mother, Verily, was writing her first book. As a way of paying the rent and supporting us five (aged from two to 13), they opened a holiday home, not for the offspring of the poor, but of the wealthy.

They rented a huge farmhouse in East Sussex. Their brochure proposed “the freedom of Old Farm Place”. There were to be no rules about bath-times or bed-times, and no locks on cupboards or doors. Guests would have unrestricted access to the larder to seek out ingredients for cakebiscuittoastfudgeginger beer-making. Carpentry tools lay on an open shelf for anyone who felt the urge to hammer, saw or chisel. Garden implements were similarly available.

The house, which opened 50 years ago this month, was timber-framed with open fires. It had no extinguishers, ladders or self-closing, heat-resistant doors. Instead, our mother held a competition to see which child could climb out of the most upstairs windows via wisteria, ivy, or down-pipes, and safely reach the ground. There were no prizes. Just survival in the event of fire.

During a pre-opening inspection by the local council, the building was criticised for the absence of low-level lavatory pans for the use of infants, although they overlooked the 30ft deep, uncovered drinking-well a few paces from the garden door. I was aware of the well’s dangers as my kitten had drowned in it. To overcome the lavatory problem, my parents explained that they’d be receiving no guests under five.

Fees were to be the same for any age: 71Z2 guineas (pound;7.871Z2) a week with all extras - outings, ice-creams on the beach, birthday cakes - included. Certain families were always offered a reduction, particularly if the parents were struggling writers or out-of-work actors (our father had worked in films between the two world wars). The children of clergy came free, for my mother was a parson’s daughter.

Neither parent had any official childcare qualifications, but, between them, they had much experience with Sunday school, Brownie packs and being an officer in the Indian Army. They got references testifying to their reliability from any lords, judges, magistrates and celebrated poets they happened to know. Staff were easily recruited from nearby cottages and the family doctor occasionally referred patients, who could become unpaid helpers on the grounds that the happy atmosphere might be good for them.

Such a relaxed attitude to minding other people’s children has, of course, long since been outlawed. Holiday centres today must conform to British Activity Holiday Association standards and the l989 Children Act. Staff must be qualified and checked by the police. They must stick to approved staff-to-child ratios. For this, parents pay between pound;300 and pound;400 a week. (A few organisations offer funding for children in special need.) My parents genuinely enjoyed the company of young people, whether fee-paying clients or 15-year-old school-leavers in green uniforms hired as staff. They ran their business in an atmosphere of extreme liberality, closer to Summerhill school founder A S Neill’s ideal of educational autonomy than to codes of army discipline.

Inevitably, there were accidents. The five-year-old daughter of a West End actress, also destined for a stage career, fell off a metal garden toy, seriously lacerating her forehead. The friendly GP, called in to assess the damage, said: “Well she can always grow a fringe, can’t she?” A Hollywood movie-star’s son dived off a breakwater at Bexhill-on-sea into shallow water, concussed himself and didn’t come up. Luckily, my youngest sister noticed and we pulled him out before he drowned. The son of a BP oil executive based in Borneo had the prongs of a pitchfork stuck in the back of his head during a garden battle. He survived, and proudly showed off his stitches.

The lack of close adult supervision allowed us to develop alternative entertainment: ambushing hikers in the lane and pelting them with rotten apples and staging multiple bicycle accidents to frighten passing motorists were favourites. The opportunity to use carpentry or garden tools as playthings encouraged strenuous activities such as diverting the stream in the meadow and digging a network of underground tunnels for a re-enactment of The Colditz Story. Tools of all types were most frequently deployed as weaponry.

Amazingly, nobody died until Christmas holidays in the second year of business. On New Year’s Eve, my mother organised a young people’s dance, to which the children of the gentry who’d provided the character references were also invited. That night, my father died, but the party, with its foxtrots and pass-the-matchbox-on-the nose, had to carry on. Towards the end of that holiday, house-guests had an extra choice of activity: attending Captain Anderson’s funeral.

My mother hired more staff. For three seasons, a real cook, wearing proper kitchen whites, came, plus her small daughter, from a nearby preparatory school. They were on harder times than my mother, living out of a suitcase.

Their only home base was in the freedom of Old Farm Place, or at the boys’ prep school. This sad rootlessness echoed that of many of the guests whose parents worked overseas, and saw them only once every two years.

Business boomed, yet never made a profit. My mother raised the fees to 91Z2 guineas (pound;9.971Z2) a week. My elder sister proposed a swimming pool.

Thus, the novelty entertainment for Easter 1958 was digging a hole, 20ft long and 6ft deep, excavated entirely by child labour. Successfully completed by mid-August, it had no water pump or filtering system and was wriggly with water-worms. Potassium permanganate crystals, kept in a nearby jar, were sprinkled in as a crude disinfectant. The pool remained unfenced and, of course, none of us had a valid safety certificate.

During term-times, Verily wrote frantically. In one of her books, a cheery account of running the children’s home, she included the accidents, near-misses, catastrophes and corrupt or inefficient staff. Far from being a deterrent, it encouraged more parents than ever to send their darlings to experience risk and disorder in the countryside.

But her book-keeping, like her childcare, remained creatively unconventional. Even raising the fees was not enough to cover running costs. She gave up the lease on the house and moved us into a cramped flat.

Another family (also five children, also ex-services father) took over the business. Change was already in the air. Freedom and juicy roasts were no longer enough. The new proprietors had a speciality to offer their clients: holidays with ponies. Forty years on, organised activity is the key to success - pony-trekking, falconry, multi-sports, aqua-sports, adventure action, chess camp, foreign languages, vegetarian cookery, themed witches and wizards.

Holiday camps now offer ever more varied programmes. One has an A-Z menu of more than 40 activities simultaneously available, from abseiling to zipwire and, in the Easter holidays this year, launched its latest high productivity offensive - “exam busters”, with “accelerated learning techniques, guidance to better performance, top 10 examination tips, mind mapping, how to study text faster, seven best strategies to never forgetting, four secrets to overcoming mental blocks”. Wistfully, I recall how, back in the 1950s, Easter, when the stream was swollen, was the best time for mud-fights.It was also the best time for lying in the grass, before the pollen-count was high, doing nothing.

Was the undisciplined, achievement-free, apparently directionless, way of allowing a large crowd of children entertain themselves an idealistic fancy on my parents’ part, or were they in fact offering an elusive and invaluable service? Is a period of total respite from all pressures to succeed, to perform, to achieve, an essential part of development that 21st-century children need now as much as ever?

The Rattletrap Trip, Rachel Anderson’s latest novel for children, is published this month by Oxford University Press, pound;4.99. It draws on life at Old Farm Place, as does her Moving Times trilogy, published by Hodder Children’s Books