Williamson is planning to step back from the day-to-day management of the group in August, when he will hand over to new managing director Steve Ashworth, who is currently director of the Wyevale Transplants operation.
The move will allow Williamson to take on a more strategic role. "There are gaps in our product range," he explained. "No nursery covers everything. We don't have a nursery that does maiden trees, fruit trees or roses, for instance.
"We don't have a grafting programme but we do have a lovely nursery that could make a grafting nursery if we had the right partner." Another area of intent would be semi-mature trees, four times transplanted and above 25cm in girth. The firm currently only grows semi-mature trees on a contract grower basis at Wyevale Hawkins.
Much of Wyevale's previous expansion has been driven by joint ventures with land owners or other kinds of partners, resulting most recently in the launch of the cash and carries Wyevale East and Greenline Plants.
"The way the Wyevale philosophy is different is that we like someone to be a partner or to be managing director of an independent company unit - a share-holding unit," said Williamson.
Nursery directors are encouraged to focus on growing, while administration and sales are handled centrally.
Commenting on the handover to Ashworth, Williamson said: "The time is right. The company needs a managing director who is here all the time."