Brook Hall Estate and Gardens

The current Brook Hall Estate is a 140-acre 18th century demesne on the banks of the River Foyle, 5 km from the city of Derry/Londonderry in the northwest of Ireland. Brook Hall has been owned and maintained by six generations of the Gilliland family since 1858, who have tended and developed the garden and arboretum into one of the finest private collections on the island of Ireland. The rich, brown earth, medium loam, and mild microclimate of the area—average year round rainfall around 1200 mm, and temperatures that rarely fall below freezing or rise above 20 °C—make excellent conditions for growing big trees quickly.

Although the original estate can be traced back to the early 17th century and the Plantation of Ulster, there are few remaining specimens from that period. Through the 18th and 19th centuries, the estate was planted as a typical country estate with many parkland broadleaf trees (Quercus robur, Q. petraea, Castanea sativa, Fagus sylvatica and Tilia ×europaea) followed by choice rhododendrons and selections of conifers.

It wasn’t until the 20th century that Commander George Francis (Frank) Gilliland, R.N.V.R., created an arboretum that included one of the finest contemporary pinetums in the United Kingdom, with specimens such as Metasequoia glyptostroboides, Fitzroya cupressoides, and Sequoiadendron giganteum.

The garden’s key collections today include over 100 species of conifers and 80 species of rhododendrons, as well as fine collections of camellias and magnolias.

One of the main attractions at Brook Hall is the 3.5 acre walled garden, which is believed to be one of the oldest and largest complete walled gardens on the island of Ireland, predating the Siege of Derry in 1689. The garden was integral to feeding the people of the city and as such played an important role in the siege, both in cutting off food to the city and as the base for the generals of King James II’s armies as they laid siege to the city.

Oaks at Brook Hall

Brook Hall is located on the edge of the City of Derry, a city which is synonymous with the oak. The city’s name comes from the Old Irish word Daire, modern Irish Doire, meaning “oak grove” and referencing the vast forests of oak that lined the valley of the River Foyle where it flowed through the city. Although these forests were considered sacred in Irish culture, the Plantation of Ulster and subsequent Industrial Revolution led to the almost complete destruction of oaks in the area. Since their strength was unparalleled among domestic trees, they were prized for building. Possibly the last maiden ancient oak still alive in the area at Brook Hall is a Quercus petraea whose girth was measured at 6.2 m in 2010.

The 18th century saw much new planting of oaks that are now of a veteran age, predominantly Q. robur rather than the more locally common Q. petraea. Brook Hall is also home to a number of Q. ilex. It was common practice for estates of this era to use them as statement trees, or marker trees, to highlight areas of significance on an estate. Two such oaks sit astride the original main road through the estate as entrance markers signifying one’s arrival to Brook Hall. Both are now of substantial girth in excess of 5 m.

With the development of the arboretum various other specimens such as Q. frainetto, Q. velutina, and Q. phellos, amongst others, were introduced. Over the last 30 years new areas of native broadleaf, predominantly oak (Q. robur), have been planted across the estate in an effort to recreate the historical oak grove landscape which has since been lost. As many of the veteran parkland trees have been lost to time and the frequent Atlantic storms, the intention is to further replant mainly oaks of various species with the aim to create an oak showcase in the heart of the City of Oak.

Special mention should be given to the story of Brook Hall’s Gallipoli Oak (Q. coccifera), grown from an acorn sent home from the Battle of Gallipoli by Private Charles Frederick Ball, who was subsequently killed in action. The acorn made its way to Daisy Hill Nurseries, Newry, where it was raised under the care of Mr. George Smith before being gifted to Commander Gilliland in 1937. The Commander was a close friend and he had also lost his first cousin, Lieutenant William Millar Major Gilliland, at the Battle of Gallipoli. Unfortunately, in the 1940s and 50s, a series of harsh winters led to the loss of Brook Hall’s Gallipoli Oak, and then the passing of Commander Gilliland in 1957 almost saw the loss of its story. In 2020, the story was found again during the writing of a book on the life of Private Ball, which has led to a plan to plant three new Q. coccifera at Brook Hall to commemorate Private Ball, Lieutenant Gilliland, and all the Irish and ANZAC soldiers who lost their lives at Gallipoli.

Conservation at Brook Hall

Many of the rare specimens at Brook Hall are of significant provenance, such as Cupressus lusitanica ‘Brookhall’, a unique cultivar propagated in the arboretum. Work has begun on propagating from these specimens to ensure their lineage at Brook Hall is maintained, and new plantings of other rare and endangered species is being undertaken to help preserve specimens for future generations.

Working in partnership with various research institutes, the wider estate at Brook Hall has been a center for research into agricultural sustainability for over 20 years. Over the next 10 years, this line of research is being extended to include the horticultural aspect of the arboretum and gardens. Extensive data collection and specimen cataloguing has been conducted using technologies such as LiDAR (Light Detection and Ranging) to create a complete 3D digital map of the landscape. Data sets include soil nutrient distribution, woody biomass volumetric analysis, and carbon sequestration levels. Collection of these data sets will be repeated over each 5-year period to provide quantifiable data on aspects such as plant and tree growth rates, impact of soil fertility improvement, and environmental benefit from green landscapes through the capture and storage of carbon.

Visiting Brook Hall

Brook Hall can be visited privately by arrangement or as part of a guided tour to enjoy the extensive collection and learn more about the history and heritage of both the estate and the botanical collections. Spring visitors will enjoy a bounty of vibrant color as the collections of camellias, magnolias and rhododendrons come into flower. Summer visitors will see the great oaks and other deciduous trees in all their glory in full leaf, and autumn visitors will witness their autumnal display as they begin to shed their leaves. For those visiting in winter, the conifers are a standout, maintaining their beauty when all else is dormant.

Photos © David Gilliland