Posted: 28/04/2016 at 09:33
Is it in the ground or in a pot?
Grevilleas like free draining sandy soil, and like most Australian natives like low phosphate so do not use bonemeal,and are drought tolerant. The roots go down deep in search of water. If it is in the ground in Cornwall, the occasional bucket of water once a week in dry periods will do. In Cornwall I suspect mother nature will provide adequately.