The library, which conserves over 800 varieties threatened from extinction, is making seedlings available from its Warwickshire site from 5 April.
"The aim is to give people the opportunity to sample old vegetable varieties that are no longer commercially available and to get more people growing," said a representative.
Produce includes Russian Red and Whippersnapper Tomato, Bronze Arrow Lettuce, peas including Ragged Jack Kale, as well as Crimson Flowered Broad Bean.
Heritage Seed Library representative Neil Munro said: "There is a real surge in the number of people wanting to grow their own food and who are interested in older varieties.
"We hope this opportunity to buy endangered plants will appeal to experienced gardeners and beginners wanting to grow something historic and unusual."
Last year Garden Organic trials compared varieties from the library collection against their commercial standard equivalents.
In many cases older heritage varieties outperformed their newer counterparts at withstanding poor weather conditions, disease and the scrutiny of taste tests.
"One such variety, the lettuce George Richardson, came out consistently on top, proving that old varieties are in many cases still the best," Munro said.