Phélan-Ségur's 66 hectares of vineyards are well-sited near the Grionde estuary and lies on well drained gravel soils. The vineyards are bordered by those of Château Montrose and Château Calon-Ségur.
Phélan-Ségur's wine is a blend of Cabernet Sauvignon (60%), Merlot (30%) and Cabernet Franc (10%). The grapes are fermented in temperature-controlled stainless steel vats and the wine is then matured in oak barriques (30% new) for 15 months.
Phélan-Ségur usually requires at least 5-7 years of bottle ageing to show at its best and the best vintages can continue improving for up to 15 years.