The reserve is owned by Oadby and Wigston Borough Council, who lease it to the Wildlife Trust. It covers 1.5 ha and has been declared a Local Nature Reserve. Grange Spinney is an area of rough grassland, which in 1991 was planted with trees including oak, ash, silver birch and hazel. The marsh itself is dominated by stands of greater willowherb and common reed, with other marshland species including blunt-flowered rush, water figwort, ragged robin and meadow sweet. A stand of large ash trees, thick mature hedges and scattered guelder-rose bushes add to the habitat diversity. To the east of the site are two large ponds surrounded by ash and willow. In the summer months blue-tailed and large red damselflies can be seen around the pounds, where moorhens and kingfishers have also bred. The range of habitats on the reserve attract a variety of birdlife including robin, wren, chiffchaff, song thrush, blackcap, willow warbler, bullfinch and great spotted woodpecker. The mature hedgerow provides food and safe roosting sites for blackbird, fieldfare and redwing. In the summer months small tortoiseshell, peacock, speckled-wood, orange-tip and ringlet butterflies visit the reserve.