A role that involves preserving Pennsylvania's indigenous plants and educating people world-wide about the value of native food.
"It's important to know the heritage of the food because food has identity in the eastern part of the United States we have incredible riches in our back yard," said Weaver.
His property in Chester County is home to the Keystone Center where Weaver raises heirloom vegetables, herbs and flowers - all from seeds he collects and trades while sharing his knowledge with the younger generation.
Owen Taylor is the Seed Collection Manager.
He said, "Heirlooms are huge and in a big part thanks to Dr. Weaver, is a global movement and it needs to be to keep the varieties alive."
Weaver inherited his love of heirloom plants from his grandfather who started the seed collection in the 1930s. Weaver has since grown it to more than 4000 varieties.
And there are the seeds.
He's published 17 books, lectures at Drexel University and mentors freely. After a lifetime of work, he feels his efforts are finally bearing fruit.
"The backyard garden has just exploded. They're growing their own food, they want to get into canning and preserving," said Weaver.
And chefs are increasingly recognizing the value of the heirloom varieties.
Palmer Marinelli, Food Activist and Cook says, "It allows you a lot more precision and a lot more intensity which is what we should be trying to achieve - not blandness, but excitement."
"It's like an encyclopedia of flavors, said Weaver."
And, for William Weaver, it's preserving what was almost a lost art.
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