The rocky islands are barren, except for scrubby yews and junipers and thin volcanic soil. Dwarf pines and yews grow on low and high slopes. Originally, the subterranean vault was surrounded by a stand of yews and hawthorns. Yews are widely used in landscaping and ornamental horticulture. This is the norm among certain coniferous plants, although not in pine trees and yews. The walled gardens have flower borders and an avenue of 200-year-old Irish yews. Bryant Fleming landscaped the grounds which included 600-year-old yews imported from England. Some of the yews at Packwood are taller than . Taxanes are complex terpenes produced by the plants of the genus "Taxus" (yews). Ten yews in Britain are believed to predate the 10th century. Some plants, including yews, are deadly and extremely fast-acting. John and Ethel lived in Kent for a time at The Yews in Longfield. The clipped yews are supposed to represent "The Sermon on the Mount". In the garden are large yews and a clock tower. It is related to the other yews in the genera "Taxus" and "Pseudotaxus".