Alan Titchmarsh has said parents are doing their children a disservice by not allowing them to get dirty.
The gardener and broadcaster added that the obsession with antiseptic wipes is stopping young people from developing antibodies.
Speaking at the Plant Heritage stand at the RHS Chelsea Flower show, he said: “Don’t force them into gardening, but for God’s sake connect them with the outdoors, get them away from these (screens) for a few hours.
“It’s the way of the world but if it’s that and nothing else and if it’s no real connection with muck, getting dirty … A lady said to me ‘What do I do about my child eating soil?’ and I said ‘Make sure he gets enough’.
“Where are your antibodies if you haven’t got muck in you as a kid? Antiseptic wipes, it’s why we all get so ill, we’ve got no antibodies anymore.”
Asked if we need dirtier children, he said: “We do! And children need to have fun, a spark in their eyes. I grew up in a different age, we played out all day, came back in the evening, or for tea, at 5pm.
“Blow all this mindfulness – get out there and get mucky.”
The broadcaster, who has four grandchildren, said: “They live about 10 minutes away so I see them every day.
“I potter with them, we are outside all the time.
“We keep chickens and grow strawberries and they love collecting eggs and feeding fish in a big pond and all that kind of thing so they are outdoor kids, which is wonderful.”