Molecular beam epitaxy has been used to grow continuous overlayers of In0.5Ga0.5N and InN on (1 1 1)Si, via growth of an intermediate nanorod arrays. Transmission electron microscopy showed that few threading dislocations are generated during nanorod growth, and are subsequently confined to twist grain boundaries 1-2 μm apart in the overlayer. In the In0.5Ga0.5N growth, the nanorods formed core-shell hexagonal wurtzite structures with In-poor surfaces, with lateral growth leading to grains with cubic zinc blende structure. High spatial resolution cathodoluminescence imaging showed that the In0.5Ga0.5N overlayers luminesced strongly, with evidence of compositional variations on the 1-2 μm scale. The reasons for compositional variations and the growth of cubic material are discussed. © 2013 Published by ElsevierB.V.