From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Planet Yardrat (ヤードラット 惑星, Yādoratto Wakusei) is a planet in the North Galaxy.
Planet Yardrat was the homeworld of the Yardrats and the planet on which Son Goku landed after he had defeated Freeza on Planet Namek. Planet Yardrat was also the planet that the Ginyu Force was scheduled to invade before being ordered to Planet Namek.
Dragon Ball Z
When Goku could not start Freeza's Spaceship, he found the Ginyu Force ships nearby and entered one of them. Goku had to leave quickly and started the engines, but he could not gain control of the ship as the coordinates for Planet Yardrat had been pre-programmed into the ship's database.
A Yardrat nursed Goku back to health, and he was later taught the Instant Transmission technique by the Yardrats. Goku stayed on the planet for a year and a half until one day he sensed that Freeza was still alive. Goku left Planet Yardrat in order to get to Planet Earth before Freeza.
Planet Yardrat was mentioned in Dragon Ball Z: The Legacy of Goku II.