Gardner, 30, has enjoyed a prolific career with Saints, scoring 173 tries in 286 appearances during the past 13 years.
“With David, Omari, Sean and Craig all missing at the moment, we are very thin in the outside backs,” explained head coach Craig Sandercock.
“That being the case, we’ve had no real option but to go into the loan market and Ade Gardner fits the bill perfectly for us.
“His record speaks for itself and he’ll bring plenty of quality and experience to the side over the next month.”
Meanwhile, it has been confirmed that 26-year-old Hall did not rupture a testicle in Rovers’ defeat at St Helens last week, with Sandercock adding:
“The scans showed that there was no rupture which is good news for Craig. However, he is very sore at the moment and we’re not sure exactly how long he’ll be missing for.”