Growth maps for core growth by accretion of 50 km planetesimals that form at either t = 0.1 Myr (top panel) or t = 0.5 Myr (bottom panel). The planetesimal population is given 1% of the gas surface density at the evolution stage of the protoplanetary disc at the chosen formation time. The protoplanets are nevertheless still started at the full range of starting times, even before the planetesimals form. Delaying the formation of planetesimals to t = 0.1 Myr reduces the parameter space for forming hot and warm gas giants significantly, while the delay to 0.5 Myr entirely removes the capability of the protoplanetary disc to form any giant planets.