  A seed layer-free growth of HfO$_2$ on commercially available CVD graphene
from various suppliers is investigated. It is revealed that the samples of
monolayer graphene transferred from Cu to SiO$_2$/Si substrates have different
coverage with bi- and multi-layer graphene islands. We find that the
distribution and number of such islands impact the nucleation and growth of
HfO$_2$ by CVD. In particular, we show that the edges and surface of densely
distributed bi-layer graphene islands provide good nucleation sites for
conformal CVD HfO$_2$ layers. Dielectric constant of 16 is extracted from
measurements on graphene- HfO$_2$-TiN capacitors.
