La Société Guernesiaise owns or leases some 50 separate areas of land, totalling some 320 vergées (130 acres). These nature reserves include the four major reed beds on the island, and some superb orchid fields, which are considered to be some of the best in the British Isles. In addition, La Société Guernesiaise manages large areas of land for the States of Guernsey.

This website describes the following Guernsey reserves:

• Pleinmont
• Silbe Nature Reserve
• Bridget Ozanne Orchid Fields
• Rue Rocheuse
• Colin Best
• La Claire Mare
• Gélé Road
• Rue des Bergers
• La Garenne d'Anneville
• Le Jardin de Lorette
• Vale Pond (Colin McCathie NR)
• Ozanne Nature reserve
• Le Grand Pré