The grower will supply trees and shrubs from next season for the project, which is a replacement for the existing road crossing over the Firth of the Forth.
Joint managing director Andrew Richardson said large jobs were much less common now.
"They’ve asked to start growing the plants early which is less common now," he said. "These days it’s often last minute and not thought about in advance. Before the recession we would have had five orders we knew about in advance."
He added: "The principal reason we won this one was that we have the quality systems and environmental standard, which means we score highly against our competitors."