We report on the growth mechanism, structure, and luminescence properties of ZnO hexagonal columns grown from Zn vapor and air plasma. Single-crystal ZnO columns grow in the [0001] direction through repeated nucleation and growth of epitaxial hexagonal pyramids on the c-planes. Homoepitaxial nucleation of three-dimensional ZnO pyramids is most likely due to the Ehrlich–Schwoebel effect. This mechanism produces columns that are a few hundred nanometers in diameter and up to 2 μm in length. Convergent beam electron diffraction shows that the columns grow with Zn polarity in the [0001] direction. Cathodoluminescence and photoluminescence measurements show near-bandedge emission (3.29 eV) with no emission associated with oxygen vacancies at 2.5 eV. © 2003 American Institute of Physics.