He is an absolutely ace television presenter, but I think that sometimes stands in the way a little as far as gardening is concerned."Hamilton's status as household god makes him a very valuable commodity. It is only when suddenly bereft of that doggedly natural tone of voice that you realise its magic. His recent illness necessitated an 11th hour substitution by Alan Titchmarsh. Hamilton himself cites Delia Smith as a kindred spirit and Desmond Lynam is of the same stamp.The ordinariness that he makes so much of makes it easy to take his silky expertise for granted. Ultimately the success or failure of any magazine-style programme will hinge on personality.

Ideally the gardener on the screen will talk simply and directly to the one in the armchair with a gentle authority that is foreign to most other areas of broadcasting. It's very hard to do and it's something I try and avoid."It is this keen awareness of his own strengths and limitations that has made Hamilton the grand old man of TV gardening. Don't go on Noel Edmonds' Fun House or whatever he calls it because you're not very good at that sort of thing.' "He once made the mistake of trying to inject a little humour into an item on seed-sowing, only to have the producer storm up in a fury: "Hamilton! Leave the fucking jokes to Morecambe and Wise." His protege has taken the advice to heart. It is slickly made and manned by a staff of gardeners who can talk and weed at the same time Geoff doesn't do chat and this is the secret of his success. "My first producer taught me most of what I know about presenting He said, 'If you're not good at something, leave it alone. "I had to give the flowers away, the room was completely choked with them," he says. The 60-year-old star is determined not to be spoilt by such adoration: "I'm worried about stopping being ordinary.

Someone phoned me the other day and said: 'I love what you do because you're so ordinary.' I take that as a compliment."Despite, or perhaps because of, the bland and unthreatening nature of both presenter and subject, Gardeners' World isn't out of place in its primetime slot. For men, he's the sort of bloke you'd like to have a pint with; for women, he's the man you'd like to put up your shelves."A mild heart attack last June prompted more than 2,000 cards from viewers. Recent offerings include two old dears videoing their vine-weevils.Ratings-hungry commissioning editors with the long-term memories of greenfly are convinced that they can pull a younger audience by portraying gardening as a cool, sexy thing to do Big mistake. The demographics of gardening are inescapable: it is something that older people do. Programmes such as Dig and Garden Party have tended to alienate this natural audience.