It's exactly the opposite when he pitches at Miller Park.
"That's as good as it gets," Milwaukee manager Ned Yost said.
Bush (5-8) allowed one run and four hits over eight innings, improving to 4-2 with a 2.64 ERA at home. He retired 23 of his final 24 batters after allowing a first-inning run.
Hart connected in the seventh to make it 8-1 and was told by Yost as he walked into the Miller Park interview room with his two young children that he beat out four other players in Internet balloting for the final spot on the NL All-Star team. A couple minutes into his news conference, about a dozen of his teammates rushed into the room and sprayed Hart and his children with beer, loudly cheering the news.
Hart said it was difficult concentrating on playing during the vote.
"It was a frustrating experience, but it paid off with all the campaigning," he said. "Now, it's worth it."
Bush's strong home record and 6.94 road ERA is such a dramatic difference that Yost is considering using the right-hander as the team's fifth starter at Miller Park and right-hander Seth McClung as the fifth starter on the road when injured Jeff Suppan returns to the rotation after the All-Star break.
"I've always been better at home throughout my career, for whatever the reason," Bush said. "I wish I knew the answer. I'd take it on the road with me."
Jorge De La Rosa (3-5) allowed seven runs in just 3 2/3 innings for Colorado. The left-hander gave up nine hits and dropped to 0-4 on the road.
"He gets that one inning that unravels on him and he's not been able to stop it," Colorado manager Clint Hurdle said. "His mechanics fall out of line."
J.J. Hardy also hit a two-run homer in the eighth for Milwaukee, his 13th of the season.
Clint Barmes had an RBI single in the first but Bush quickly settled down.
The Rockies got a leadoff single from Matt Holliday in the fourth, but Bush retired 14 consecutive batters before giving up a two-out double to Jayson Nix in the eighth. Carlos Villanueva pitched the ninth for Milwaukee.
The Brewers are 21-9 when facing a left-handed starter. ... Holliday was named a starter for the NL All-Star team, replacing injured Chicago Cubs OF Alfonso Soriano. Holliday's fourth-inning single extended his hitting streak to 14 games. ... The Brewers have hit at least one home run in 10 consecutive games. ... Bush's fifth-inning strikeout of Luis Vizcaino was the 500th of his career.