The forward has started the season in fantastic form with six goals in his first seven league games.
Berbatov arrived in the summer of 2008 from Tottenham, but struggled to live up to expectations prior to the current campaign.
Now he is starting to deliver Ferguson insists that he had little doubt that Berbatov just needed time to find his confidence.
"I just had a word with him at the start of the campaign," said Ferguson.
"I told him: 'Look, only you can solve this conundrum. You're the one in control here. You've got fantastic ability and you need to realise that ability and make the most of it. We'll be here to support you'.
"And he's started the season in terrific form for us. Dimitar has been, without doubt, our star forward."
Ferguson feels any player signed by United generally needs time to adapt to the club.
"When you bring a player to Manchester United, not everybody takes to the situation straight away.
"Not all signings become hits overnight.
"Valencia did, of course, but he's almost an exception. Others take time, and Dimitar was a bit like that. It's just a fact.
"Nobody's ever doubted the ability of the lad, but what we're seeing now is a striker who's playing with belief and confidence.
"All strikers are massively reliant on those two factors - belief and confidence.
"And at the moment Berbatov has both."