  The spin-incoherent regime of one-dimensional electrons has recently been
explored using the Bethe ansatz and a bosonized path integral approach,
revealing that the spin incoherence dramatically influences the correlations of
charge excitations. We here introduce a bosonization scheme for strongly
interacting electrons, allowing us to generalize the description to account for
the presence of an open boundary. By calculating the single-electron Green's
function we find that the charge sector power-law scaling is highly sensitive
to the boundary. Our result allows for a detailed description of the crossover
between boundary and bulk regimes. We predict that scanning tunneling
microscopy on a spin-incoherent system will pick up oscillations in the
differential tunneling conductance as a function of the applied voltage $V$ at
"intermediate" distances $x$ from a real or a dynamically generated boundary.
The wavelength of the oscillations, $\pi v_c/x$, probes the speed $v_c$ of the
charge excitations, and therefore the strength of the electron-electron
interaction.
