The Bishop's Palace or Castle in Llandaff, Cardiff, was the residence of the medieval clergy of Llandaff. It was shown on John Speed's plan of Llandaff published 1610, and is thought to have been dismantled later in the seventeenth century. The ruin is a grade 1 listed building.
In 1948 Cardiff Council entered negotiations with the church authorities to obtain the land adjoining Bishop's Palace. The church authorities were prepared to transfer the land to the Council for laying out as an ornamental small park.
Terms were agreed for the free conveyance to the Council in 1971. A sum of £16,500 was included in the financial estimates for 1971-72 to undertake structural repairs, provide a viewing platform and carry out landscaping work. The site was opened as a public garden in 1972. In that year it received a silver rose bowl award from the Wales in Bloom Committee, a Prince of Wales Award. and a Civic Trust Award. There was a further award in 1975, a special commendation in the British Tourist Authorities Landscape Heritage Competition of that year.
The refurbishment involved both planting and structural work such as repair or re-building of walls. The Civic Trust Award included the following description of the work:
This fortified Palace, built during the 13th and 14th centuries, went out of use in the early 15th century. It fell into ruins, and the land has until recently been used as an allotment garden. The principal value of this new public garden lies in the recovery of a previously neglected area of land for a worthwhile purpose. The ancient walls, turrets and gateway have been unobtrusively repaired and restored, and the plants selected in the landscaping are specifically in keeping with the monument as a whole (including a traditional herb border,aromatic shrubs and mulberries). The Corporation has taken these crumbling walls and overgrown ground and has created, with imagination and care a positive and valuable asset - a delightful garden surrounded by the undeniable charm of mediaeval ruins.
A small mess-room for parks staff was built into the new wall at the north east corner. In the 1990s the mess-room was destroyed in a fire.
The planting scheme included a herb border at the north end, containing among others Rosemary, Sage, Thyme, Hellebores and a variegated form of Ground elder (Aegopodium podagraria). On the north wall between the herb border and the entrance, was a Trumpet vine (Canpsis radicans). The east and south borders were mixed herbaceous and the south wall was covered with Virginia creeper (Ampelopsis quinquefolia). The west wall was covered with Climbing hydrangea (Hydrangea anomala subsp. petiolaris), which is still present. Pockets were made in the wall for further plants, thought to be Mint bush (Prostanthera). The west path was (and still is) bordered by a Box hedge.
Tree planting at the same time included the group of Mulberries on the lawn and a Common fig (Ficus carica) - a Wales champion tree - in the south east corner near the gate. Also in this corner, against the east wall, is a Winter's bark (Drimys winteri), a Glamorgan champion tree.
Sources of Information