Harborough District Council says it has bought a site near Market Harborough for £1.9m.
The large Victorian walled garden at Peckover House in Wisbech is proving a hit with locals.
A 300-acre (121-hectare) wetland habit experiences a 10-fold visitor boost.
Enrolment on outdoor learning courses is "through the roof" as teachers increasingly turn to nature.
Educating pupils in nature releases stress of masks and social distancing, say teachers.
