MANY thousands of varieties of vegetables and plants are lost due to climate change, natural disasters, war, outbreak of disease and poor agricultural management.
Which is why projects such as the Millennium Seed Bank at London's Royal Botanic Gardens in Kew and the Svalbard Global Seed Vault on the Norwegian island of Spitsbergen are vital. They are preserving the world's food supplies and native vegetation as a means of protecting biodiversity.
Built underground and opened in 2008, the Svalbard vault is the ultimate safety net for the world's seed collections, storing food staples such as maize, rice and wheat.
The staff at Kew, meanwhile, work with partners across 50 countries, including Australia, focusing on plants at risk of extinction and those most useful in the food chain.
The Victorian Conservation Seedbank is in the National Herbarium at Melbourne's Royal Botanic Gardens and targets seeds from rare or threatened species.
Seeds have also been sent into space to provide an insurance policy for our precious resources.
Clive Blazey from Diggers Seeds knows the importance of preserving heirloom fruit and vegetable seeds, and offers members of his Diggers Club 400 varieties from the American Seed Savers Exchange, which has preserved 25,000 varieties from around the world. Blazey's attitude to hybrid fruit and vegetables, especially tomatoes, is unequivocal.
''It's good for the bottom line of supermarkets [because they're grown for a long shelf life] and seed merchants, but not for gardeners who want to produce quality food,'' he says.
While home gardeners are keen to provide healthy produce for their families, so too are chefs and restaurateurs, many of whom now grow their own vegetables either on site or in allotments. Ben Shewry, from the award-winning restaurant Attica, has a large plot at Rippon Lea where he grows herbs and vegetables harvested by staff daily.
''The chef at the Royal Mail in Dunkeld is also passionate about heritage vegetables and he gets a lot of seed from us so he can grow his own,'' Blazey says. ''These people are trailblazers, so if you're passionate about the quality of food then you have to grow it yourself or go to a restaurant where the chef is equally passionate.''
Blazey says ''mainstream gardening'' is now ''picking up on heritage'', with companies such as Bunnings stocking Diggers Seeds, and Yates and Oasis Horticulture also offering heritage varieties.
According to Blazey, the ''poster child'' of heirloom seeds is a five-colour silverbeet that can be found in the Vilmorin catalogue of 1850.
But not all colours have appetite appeal, Blazey says, citing red as a turn-off even though it looks good on the plate.
''I remember Hermann Schneider from the Two Faces restaurant, who taught me about food colour. He said black wasn't a good food colour and neither was red.'' Blazey says the French and Italians have withstood the influences of American fast-food traditions and hybridisation.
''A friend who takes gourmet tours to Italy sent me some catalogues from a small region just north of Lucca. I looked up 30 different apples and none of them bear any relationship to anything I've seen in France, England, America or Australia. So that's where our focus is growing. We list three chicories, but serious Italian foodies would know 10 varieties.
''The Italians won't deal with us. They collect their own seed and haven't been overrun by hybrid varieties; instead they want regional and fresh foods.''
Blazey says the growing band of heirloom aficionados is testament to a desire for good food and flavours and a will to reduce carbon footprint. ''So this renaissance of the interest in heritage vegies is not a fad thing. It's very real.''
■The Diggers Club Garden Annual 2012-13 Seed Sowers Manual is available from diggers.com.au.