  We calculate log corrections to the entropy of three-dimensional black holes
with "soft hairy" boundary conditions. Their thermodynamics possesses some
special features that preclude a naive direct evaluation of these corrections,
so we follow two different approaches. The first one exploits that the BTZ
black hole belongs to the spectrum of Brown-Henneaux as well as soft hairy
boundary conditions, so that the respective log corrections are related through
a suitable change of the thermodynamic ensemble. In the second approach the
analogue of modular invariance is considered for dual theories with anisotropic
scaling of Lifshitz type with dynamical exponent z at the boundary. On the
gravity side such scalings arise for KdV-type boundary conditions, which
provide a specific 1-parameter family of multi-trace deformations of the usual
AdS3/CFT2 setup, with Brown-Henneaux corresponding to z=1 and soft hairy
boundary conditions to the limiting case z=0. Both approaches agree in the case
of BTZ black holes for any non-negative z. Finally, for soft hairy boundary
conditions we show that not only the leading term, but also the log corrections
to the entropy of black flowers endowed with affine u(1) soft hair charges
exclusively depend on the zero modes and hence coincide with the ones for BTZ
black holes.
