Winter in The Walled Garden Winter is an important time for the Arboretum and Horticultural Team at Marks Hall Estate. Designed for the Spring and Summer season, the Walled Garden is closed during the winter period. From November, after the commencement of winter opening hours, important maintenance tasks begin in the Walled Garden. It is necessary for the Estate to close the Walled Garden so that these large tasks can be carried out. This time period is also important for the ground conditions to restore following the busy summer season. Within the first few days of closure, maintenance tasks began with the moving of our large Escallonia trees as well as a number of other shrubs.