Steve Taylor, who is involved in Kew Gardens' Ethnomedica project to collect old remedies, will headline the Wholly Herb event on 16-17 May.
"It's important we don't lose this knowledge," he said. "It has taken generations to build up and it's so sustainable, in fact many folk remedies are free."
West Dean Gardens supervisor Sarah Wain will show visitors around the site's walled kitchen gardens. They will be able to learn about aromatherapy plants and culinary herbs and their uses, growing, harvest details and continuity of supply.