A collection of heritage lettuce varieties has outperformed its commercial counterparts in new findings by the UK’s leading organic growing charity.

In research trials carried out by Garden Organic, funded by the EU, the charity found that 12 heirloom accessions from its Heritage Seed Library collection performed better than the next best commercial standard by showing greater ability at withstanding poor weather conditions and downy mildew, as well as the scrutiny of taste tests.

Garden Organic’s Heritage Seed Library, which has been protecting endangered vegetables under threat from extinction since the 1970s, has a collection of more than 800 vegetable varieties of which seeds can no longer be bought.

The research took Garden Organic’s lettuces and compared them with several commercially available standard varieties, to see which would show most promise against a range of criteria.

Despite the commercial lettuces being bred to withstand certain types of disease and weather conditions, a recurring top contender proved to be an heirloom Cos lettuce variety known as George Richardson.

During the trials, in which infection levels of downy mildew (the most damaging disease to lettuce) were recorded, George Richardson was given a rating of 7.5 on a 1-9 scale with nine being the least infected.

Only one other commercial variety, Kitare, beat this. George Richardson also withstood frosts well, showing almost no damage to its leaves after a significantly cold frost.

Phil Sumption, research officer at Garden Organic, said: “The research results were surprising and clearly showed the potential of heritage or landrace varieties. With climate change we need varieties that are robust and those from our Heritage Seed Library performed well under severe weather and disease pressure. Garden Organic is confident that there is potential for re-introducing some of the varieties or using them in breeding programmes in the future.”

Topics