When you hit on something successful, you stick with it. Last year, local roots-rock favorites Blue Dogs celebrated their 25th anniversary with a holiday show the Sunday after Christmas, and it was a sold-out sensation.

“Everybody sort of showed up,” recalls singer/guitarist Bobby Houck. “We didn’t have enough time to rehearse. We had this great backing band, much bigger than usual, and guests just showed up and sang. So Darius Rucker sang ‘Isabel.’ He had the lyrics at his feet, and you can see in the video he looked down one time and nailed it. Edwin McCain came and sat in. That’s how it went. Everyone did a Blue Dogs song and maybe one of their songs.”

The show proved so popular they’ve decided to make it an annual affair with this year’s proceeds going to the Medical University of South Carolina’s Children’s Hospital, and they’ve enlisted more of their friends. Pat McGee, whom they toured with in the mid-’90s while supporting Train, will be making an appearance, as will Five Way Friday, Uncle Mingo, and Jupiter Coyotes’ Matthew Mayes and John Felty. There may be an unannounced guest as well.

“It’s the perfect time of year, right after Christmas but before New Year’s,” Houck says. “It’s a great time to invite a bunch of friends to show up and play, have people come from out of town to play, and fans to see the show.”

It’s also a great chance for Houck to get together with his work-wife Hank Futch, a friend since they first met in Cub Scouts when they were eight years old. They reconnected in high school when they discovered their shared love of music and fortuitously complementary instrumentation.

“We went to a small school that had like 25 people in the class,” Houck recalls. “Out of that 25, there aren’t that many musicians. The fact that you had two guys in the same class and one plays bass, the other plays guitar, and we kind of jived together. It’s really the same deal now. We just want to keep playing.”

The Blue Dogs got started in the late ’80s, released their debut Music for Dog People in 1991, and broke out with 1997’s self-titled, third studio album. But while other Southern roots artists like Shawn Mullins, Counting Crows, McCain, and Hootie were able to secure major-label deals and varying degrees of commercial success, the Blue Dogs never made that leap.

Hindsight is more powerful than X-ray-vision glasses and only a little more useful.

“You’d definitely look at us in 1996 and go, ‘Don’t try and get a rock record deal and follow the Hootie and Eddie McCain thing,'” Houck offers ruefully. “If I had it to do all over again, I’d go to Nashville, because I think we’re more like a Zac Brown.”

Sure, the Blue Dogs are Americana, but that was barely even a style at the time. And when it started to take off as a genre, the band was exhausted from 10 of years chasing the dream. It got shelved in favor of marriage, kids, and stable jobs.

“We fall in between the cracks,” says Houck, explaining the trouble with their varied approach. “People think we’re a bluegrass band, but we’re not a bluegrass band. We’re a little bit like that. We’re not bad bluegrass.

“We’re not really a country band — we don’t wear cowboy hats,” he jokes. “Other people labeled us a jam band for a while, but look at us. We’ve done jams, and I saw 15 Grateful Dead shows — we grew up in that era, but we’re not a jam band.”

The Blue Dogs have the boogie of Southern roots rockers, and even a little Big Easy rhythm and blues at times. They’re even a little folky, but the Blue Dogs are mostly just rockers who know where they came from.

“We are 100 percent Americana,” Houck says. “We like that Drive-By Truckers ethos, but we don’t sing about dying in a Motel 6 or doing methamphetamines. We’re far too happy for a lot of Americana critics.”

If there’s a band that epitomize what the Blue Dogs are going for, it’s Little Feat, whose first three albums in the early ’70s are overlooked classics, particularly 1973’s Dixie Chicken.

“There are actually a couple of songs on our debut that were as close to Little Feat as we could come,” Houck chuckles.

He knows it’s been “an insanely long period” without any new music from the Blue Dogs, though he notes with three- and five-year-olds at home, time’s been at a premium. Houck did write a couple of songs with country music singer/songwriter and producer Radney Foster last year that are going to be demoed for someone to potentially cover.

Houck’s also written new Blue Dogs music to go with some long-simmering projects. By this time next year, the band should have completed an album of Christmas songs (they recently released a cover of “Little Drummer Boy”) and a children’s record, for which they’ve already cut several tracks.

“We’re not trying to make something ‘happen.’ All that shit is long over,” Houck says. “I’d just like to get some new music out there for myself, so I can show I write just as well as I have or better.”

Beyond that, Houck’s just happy to have landed upon something that will keep him well-occupied into his golden years.

“If they’ll keep paying me, why should I stop?” Houck laughs. “I tell people it’s like having a weekend golf game, except people don’t pay you to play golf.”