Media Types: The gardening expert: They love to boast about their brassica

THEY HAVE a shorter flowering season than almost any other bloom in the media jungle. For 51 weeks in the year they are shade-lovers, lurking in the obscurity of the back pages of papers and magazines. Then, forthe week of the Chelsea Flower Show, writes Fred Trowel, they are allowed to blossom freely, and even spread their tentacles on to the news pages.

There are two distinct categories of gardening journalist. First the experts, the ones who know their antirrhinums from their aquilegias. These used to be rough-handed veterans, former head gardeners at stately homes, usually named Fred. Today, they are as likely to be academics, decorated with doctorates in plant biology, fluent in the habits of a hundred kinds of aphid. On programmes such as Gardeners' Question Time, and in advice columns in the press, they wear their expertise genially, although the questions (What plants give winter colour? What can I do about slugs?) and answers have stayed the same for generations.

The other kind are not experts in horticulture but in style. Their subject is gardens rather than gardening. They are given tours of the most lovingly tended acres in the land, and describe them for glossy magazines or television programmes. For that, you need no specific knowledge, just an outgoing manner and a large repertoire of superlatives. Hostile interrogation ('What on earth made you plant this purple clematis alongside that clashing scarlet rose?') is not permitted.

Although garden journalism is not regarded in the trade as glamorous, the writers comfort themselves with the knowledge that they are covering the country's most popular pastime. They could not do it if they were not passionate about it: they spend hours tending their own gardens, which are usually as immaculate as you would expect. Visitors would quickly rumble a garden writer with rampant greenfly.

Like gardening itself, writing about it is a solitary activity, and on only a few occasions do we green-fingered scribes get together. One is this week's lunch given by the president of the Royal Horticultural Society, in a marquee at Chelsea. And every January the RHS summons us to its annual press conference, just to make sure we are over-wintering nicely.

These are companionable occasions, for garden writers are the least competitive of journalists. Occasionally, there is a hint of rivalry among the television people, but for the most part we are a relaxed bunch who merely ask to plough our furrows in our own way.

We do not compete for exclusives, for there has not been a gardening scoop since Eve discovered the apple. Nor, unlike almost every other kind of journalist, do we exchange office gossip: we are hardly ever in the office, so we don't know any. Instead, we boast about the phenomenal size of our brassica.

At the end of the summer the seed merchants launch their catalogues, inviting us to places as distant as Ipswich and Torquay. Here we are allowed to stock up on free packets, but in general the gravy train for gardening journalists is not stacked with goodies. We may get the loan of the odd lawn mower, but we are not invited to Sierra Leone to test it.

The most elaborate gardening freebie I have enjoyed involved getting up impossibly early for a flight to Jersey, which, for no clear reason, had been chosen as the place to launch a wood stainer for garden fences. After the launch, we were taken on a tour of the Germans' wartime underground headquarters and then presented with walking sticks made from giant cabbage stalks. By the humble standards of gardening writers, that was a big day out.