A YEAR-long study by the National Trust has revealed that the UK's 27 million gardeners could go peat-free tomorrow, using other types of compost for the majority of plants - and at the same time taking the pressure off the world's threatened peat mires and bogs.

The trust and English Nature also announced a plan to harvest bracken from English Nature sites in East Anglia to be turned into compost for acid-loving plants such as rhododendrons and azaleas, which grow well in peat.

The trust conducted the trials at 14 of Britain's major gardens. Two-thirds of peat extracted in the UK for horticulture is used by amateur gardeners but, with 94% of the UK's lowland raised bogs lost to extraction since the nineteenth century, species such as sphagnum moss and Britain's largest carnivorous plant, the great sundew, are leading an increasingly fragile existence.

Only six months ago, Scottish Wildlife Trust, champions of the peat bog north of the border, began pressurising the Scottish Executive to give 17 additional peat bogs protection, claiming the 23 lowland bogs listed by the executive's own agency, Scottish Natural Heritage, was inadequate.

SWT said they were under imminent threat from English-based peat extraction companies looking north of the border as more and more English peatlands were declared special areas of conservation.

The problem is not confined to the UK. A powerful group from the universities of Stirling, Aberdeen, and Dundee, Macaulay Land Use Research Institute at Aberdeen, SWT and SNH are already in talks with former Soviet Union countries whose remaining peatlands face exploitation by UK and German extraction companies.

The 14 countries involved, from Russia to the Baltic states, are benefiting from a UK government initiative aimed at helping nations rich in biodiversity but economically straitened.

A network of about 800 people will develop education programmes and national strategies for preservation.

Stuart Brooks, a peatland expert at SWT, said the fear was that companies feeding the gardening market were looking eastwards for new resources as the UK closes to them and Ireland reaches the limits of extraction.

Mr Brooks said: ''It has become more or less impossible for them to develop new sites here. Countries such as Russia, with 20% of the world's remaining peat resource, will be tempted because they need the dollars.''

He said the problems were global. Countries such as Canada, a huge producer for their home and the American market, are facing the same dilemmas over conservation versus extraction. American companies were thought to be casting envious eyes at the vast resources in Chile, Patagonia, Tierra del Fuego, and even the Falklands which, like the near-pristine Siberian resource, is currently protected by isolation.

Use of peat among UK consumers has soared over the last decade, rising 50% between 1993 and 1997, because of the boom in gardening and the popularity of patio pots and hanging baskets.

A range of the most popular garden plants, such as begonias, geraniums, petunias, and dahlias underwent trials in a range of alternative mixes, including coir, a coconut by-product; green garden waste compost; forestry or wood industry by-products; chipboard waste; leaf mould and composted bracken.

They are the first such trial results to have been made available to the gardening public and are being published via the National Trust members' magazine.

Fiona Reynolds, director general of the National Trust, said: ''Amateur gardeners are the biggest consumers of peat supplies by the horticultural industry but many people are not aware our passion for gardening is contributing to the rapid disappearance of one of the UK's most vulnerable nature conservation habitats.''

Martin Doughty, chairman of English Nature, said: ''Peat bogs are a unique and highly precious habitat which English Nature wants to see survive for future generations to enjoy.