Watering your landscape is a good idea after a fire. Because of intense heat from the fire, soils may be dry and plants may be desiccated; thus, watering can be very beneficial in helping them recover. Some may have dried to the point where they are actually dead, but it may be difficult early on to determine whether they are really dead. Before removing them, check to see if they are alive and could re-sprout.
If your landscape plants have been coated with fire retardant, wash them as soon as possible as the retardant will burn foliage.