The Sand Banks are a south-facing slope at between 80 and 95 m AOD with acidic, very sandy soil. This is reflected in the heathy grassland vegetation characterised by wavy hair-grass (Deschampsia flexuosa), creeping soft-grass (Holcus mollis), common bent (Agrostis capillahs), tormentil (Potentilla erecta) and heath bedstraw (Galium saxatile). Wood sage (Teucrium scordium), sheep's sorrel (Rumex acetosella), common birdsfoot trefoil (Lotus corniculatus), catsear (Hypochaeris radicata) and heath speedwell (Veronica officinalis) occur more locally with occasional bitter vetch (Lathyrus montanus), pill sedge (Carex pilulifera) and heath wood rush (Luzula multi flora).
The parched, sparsely-vegetated ground of the old sand pit supports catsear, mouse-ear hawkweed (Pilosella officinarum), early hair-grass (Aira praecox) and various mosses. This is also habitat for an interesting assemblage of 'heathland' insects including the Green Tiger Beetle (Cicindela campestris), mining bees, spider-hunting wasps and ruby-tailed wasps.
Small areas of species-rich dry grassland on banks near Ganthorpe Lane support birdsfoot trefoil, common knapweed (Centaurea nigra), cowslip (Primula veris) and common spotted orchid with salad burnet (Sanguisorba minor) and upright brome (Bromopsis erecta) indicating the influence of the underlying limestone.
Another area near Ganthorpe Gate supports species typical of moderately acidic grassland, including a colourful mixture of betony (Stachys officinalis), devilsbit scabious (Succisa pratensis), barren strawberry (Potentilla sterilis) and tormentil. There are also other patches of grassland within the Arboretum supporting species such as common spotted orchid and cowslip.