David Nash is known for works in wood and shaping living trees. His large wood sculptures are sometimes carved or partially burned to produce blackening. His main tools for these sculptures are a chainsaw and an axe to carve the wood and a blowtorch to char the wood.

Nash also makes land art , of which the best known is Wooden Boulder, begun in 1978. This work involves the journey of a large wooden sphere from a Welsh mountainside to the Atlantic Ocean. Wooden Boulder is a large wooden sphere carved by Nash in the North Wales landscape and left there to weather. Over the years, the boulder has slipped, rolled and sometime been pushed through the landscape following the course of streams and rivers until finally it was last seen in the estuary of the river Dwyryd. It was thought to have been washed out to sea but, after being missing for over five years, the boulder reappeared in June 2009. Indications are that it had been buried in sand in the estuary. The sculptor had no idea of its location, and enjoys the notion that wood which grew out of the land will finally return to it. The boulder was last seen in 2015.

Nash also makes sculptures which stay in the landscape. For example, Ash Dome is a ring of ash trees he planted in 1977 and trained to form a domed shape. The dome is sited at a secret location somewhere in Snowdonia and whenever it is filmed, crews are taken there by a circuitous route to guard its security.