  Incorporating free boundary into time-delayed reaction-diffusion equations
yields a compatible condition that guarantees the well-posedness of the initial
value problem. With the KPP type nonlinearity we then establish a
vanishing-spreading dichotomy result. Further, when the spreading happens, we
show that the spreading speed and spreading profile are nonlinearly determined
by a delay-induced nonlocal semi-wave problem. It turns out that time delay
slows down the spreading speed.
