The holm oaks of Ventnor Downs

A mature holm oak showing mostly trunk on the edge of the wood. — Holm oaks on Ventnor Downs

A level path leads across a steep slope, all under the canopy of holm oaks — The path through the holm oak wood crosses the 30-degree slope of St Boniface Down

Holm oaks on Bonchurch Down — The characteristic browse line, the height reached by the goats' nibbling

A mass of brown dry leaves under holm oaks, and nothing else grows — Holm oak leaves decay very slowly, leaving a dense covering underfoot

Areas of trees and open land on St Boniface Down above Ventnor town — The goats help to keep areas of Ventnor Downs hillside open by nibbling the holm oak

The largest holm oak wood in northern Europe can be found on Ventnor Downs on the Isle of Wight but it proved invasive.

Origins

The holm oak, Quercus ilex, is one of the few evergreen oak trees in the country but it is not a British native. It was introduced from the Mediterranean in the 1600s and brought to Ventnor in the 19th centuary by the Victorians, who returned with many exotic plants from their travels abroad.

The holm oak proved to be invasive. Its spread across Ventnor Downs is thought to have been assisted by jays collecting and burying acorns.

The tree thrives in the unusually mild climate at Ventnor and copes well with the dry chalk soils and its exposed coastal location – its glossy leaves are resistant to salt winds.

The history of the Holm oak

It was known to the Romans, who used its hard wood to make cartwheels and wine casks, and to the Ancient Greeks who honoured people with crowns made from holm oak leaves.

Today, it is one of the top three trees used in truffle orchards. The holm oak gets its name from its spiny, toothed leaves. These resemble holly leaves – 'holm' being an old word for holly.

Glossy (water retaining) holm oak leaves — The glossy leaves of the drought-resistant holm oak, ideal for Mediterranean conditions

Chalk grassland under threat

The spread of the holm oak poses a serious threat to the chalk grassland here, causing butterfly and insect populations to dwindle. We had to find a means of control.

Trees and scrub were removed in the 1980s but a longer-term solution was needed to prevent re-growth – holm oak doesn't respond well to herbicides.

A documentary on how feral goats decimated a Spanish holm oak wood provided the key. Why not use goats to control holm oaks on Ventnor Downs?

Goats vs holm oak

In 1993, seven feral goats were brought from the Valley of the Rocks in Devon to start a new life here. Today, there's a small breeding herd with a good appetite for bark stripping and browsing new growth.

Year by year, we hope to see the return of special chalk grassland plants, butterflies and insects.