Before the industrialization of agriculture a much wider variety of plant foods were grown for human consumption. In modern agriculture in the industrialised world, most food crops are now grown in large, monocultures. In order to maximize consistency, few varieties of each type of crop are grown. These varieties are often selected for their productivity, their ability to withstand mechanical picking and cross-country shipping, and their tolerance to drought, frost, or pesticides. Heirloom gardening is a reaction against this trend. In the Global South, heirloom plants are still widely grown, for example in the home gardens of South and Southeast Asia.
An heirloom plant, heirloom variety, heritage fruit (Australia and New Zealand), or (especially in the UK) heirloom vegetable is an old cultivar that is "still maintained by gardeners and farmers particularly in isolated or ethnic communities". These may have been commonly grown during earlier periods in human history, but are not used in modern large-scale agriculture. In some parts of the world, notably the European Union, it is illegal to sell seeds of cultivars that are not listed as approved for sale. The Henry Doubleday Research Association, now known as Garden Organic responded to this legislation by setting up the Heritage Seed Library to preserve seeds of as many of the older cultivars as possible. However, seed banks alone have not been able to provide sufficient insurance against catastrophic loss.
Many heirloom vegetables have kept their traits through open pollination, while fruit varieties such as apples have been propagated over the centuries through grafts and cuttings. The trend of growing heirloom plants in gardens has been increasing in popularity in North America and Europe in recent decades.
The Henry Doubleday Research Association began in 1954 as a result of the inspiration and initiative of one man, Lawrence Hills. As an horticulturalist he had a keen interest in organic growing, but he earned his living as a freelance journalist. Whilst researching a book called Russian Comfrey, he discovered that the plant grown widely in Britain today was introduced in the nineteenth century by a Quaker named Henry Doubleday. HDRA is now Europe's largest organic membership organisation. It is dedicated to researching and promoting organic gardening, farming and food, and holds a large seed library of heritage vegetables.
The Heritage Seed Library (HSL) aims to conserve and make available vegetable varieties that are not widely available. The HSL maintains a collection, mainly of European varieties. Over the decades many varieties have been dropped from popular seed catalogues. Our collection contains many of these but also some landraces and a large number of family heirloom varieties that have never been in a catalogue. We are not a gene bank and all our collection, once we have enough seed will become available to our members. This membership service is free and growers are encouraged to send back seed they harvest from their own crops to augment the stocks. The system of seed-to-seed depends on the presence of pollinators and participation in a community seed saver scheme is another community dimension of a nectar point network.