The long summer holidays are here. While parents are wondering how to keep the children occupied, spare a thought for grandchildren. For six whole weeks they may have to cope with an even greater challenge – grandparents with time on their hands.

Children know the signs. Grandma suddenly appears with a packet of wet wipes, asking if anyone wants to bake scones. Grandad announces that it's "a lovely day for a walk" just as the latest computer game has reached a crucial level. Before long, there are suggestions involving museums, castles, steam railways and somewhere called "a fascinating heritage centre." The poor youngsters don’t stand a chance.

Something must be done. If children are to enjoy their summer in peace, they need to find ways of keeping their grandparents fully occupied.

Fortunately, members of Soar Valley u3a are already experts at being busy. With interest groups covering everything from walking and cycling to photography, gardening, history, languages, crafts and book clubs, there are countless opportunities to disappear for a few hours. And, annual membership is not expensive so there should still be a little cash left over for treats. Grandchildren can relax, safe in the knowledge that Grandma is reading a Shakespeare Play while Grandad is trying to remember the difference between a chiffchaff and a willow warbler.

Of course, summer provides the perfect opportunity for grandparents to tackle all those jobs that have been waiting patiently since last autumn. The garage could be tidied. The shed could be organised. Family photographs could finally be labelled before everyone forgets who Uncle Fred actually was. There are books to read, vegetables to grow, bicycles to polish and holidays to plan.

Then there are all those hobbies that retirement was supposed to provide time for. Watercolours that have remained in their box. Model railways waiting for another station. Half-finished quilts. Ukuleles with only three chords mastered so far. Summer offers the ideal opportunity to make progress while the grandchildren enjoy uninterrupted freedom elsewhere.

Technology, too, provides endless distractions. Grandparents can spend hours trying to organise thousands of digital photographs, learning new computer skills or attempting to understand why the television remote now appears to control three devices instead of one. By the time everything is working again, several days of the school holiday may have passed.

Naturally, grandchildren shouldn't leave grandparents entirely unsupervised. They should check occasionally that they are keeping hydrated with regular cups of tea, that biscuit supplies remain adequate and that no one has become trapped behind an avalanche in the loft while searching for old camping equipment.

In truth, both generations know the arrangement works rather well. Children enjoy having grandparents who have time for them, who listen to endless stories, attend sports days, admire every drawing and somehow always have ice cream hidden somewhere. Grandparents, meanwhile, discover that a few hours spent with energetic youngsters is wonderfully rewarding, even if it does require a quiet sit-down afterwards.

So perhaps the real challenge this summer isn't keeping the grandchildren busy at all. It is ensuring that grandparents continue to lead the active, interesting and fulfilling lives that organisations like Soar Valley u3a make possible. After all, the busier the grandparents are, the more exciting stories they have to tell when everyone gets together again.

And if, after all that, Grandma still insists on baking scones and Grandad still suggests "just a short walk", perhaps the grandchildren should give in gracefully. One day they'll realise those were the very moments that became their favourite holiday memories.