Hastie was born in Edinburgh but was brought up and educated in Berkhamsted, attending Ashlyns School. His poems were first published in the 1970s and several collections of poems followed, including Titan in the Shadows (1975) and Still Breathing (1984).
Additionally, Hastie is also a keen local historian writing books on Hemel Hempstead and Kings Langley and he completed a novel, Reunion (2003). Most recently he has published a collection of poems, titled Meditations, in 2013.