He lost 600 avocado trees to the frost that invaded Southern California in January. He's down to two sheep, and the rabbit died. But actor Tom Selleck still has six dogs, two cats, nine horses, a 63-acre ranch and one burly ranch hand — himself.

"Yeah, I could pay somebody to do it, but I'm cheaper and I don't like going to the gym," he says.

Most people know Selleck as the star of TV's classic "Magnum, P.I.," guest on "Friends" and "Boston Legal," and as the small-town police chief who's carrying a big torch on the CBS series of "Jesse Stone" movies. (And next season, he takes the new lead in the NBC series "Las Vegas," in the wake of a departing James Caan.)

Selleck will return to the Stone persona tonight in "Sea Change." It's the fourth movie based on Robert B. Parker's world-weary character, and it fits Selleck like a pair of old jeans.

Just as "Magnum, P.I." displayed Selleck's antic, sweet nature, "Jesse Stone" captures something deeper — his sense of loss and loyalty. Stone is a tragically flawed character, just the kind the actor thrives on.

It was the hang-loose Thomas Magnum of "Magnum, P.I." that settled Selleck into the public consciousness. And though he was an unknown actor with six failed pilots behind him, he at first refused to play the part.

"I didn't like that first script. He was perfect. He had a woman on both arms. He never failed. He owned the Ferrari. ... But I knew that's not what I should do and I said I won't do it. They said, 'Who the hell do you think you are, you've never been on the air?' I said, 'Nobody, but I know what I should do.' And it was working with people like (Jim) Garner that taught me. I said, 'I want to play a more flawed character. I want to play a guy more like Rockford.' "

It was a risky thing to do because he was under contract to Universal, the production studio.

He was playing a small part on "The Rockford Files" and sought Garner's advice. "I said, 'I'm not sure what to do. Universal's assigning this show to me.' He said, 'Do you like it?' I said, 'No.' He said, 'I don't know how much power you have, but I can tell you this: you're never going to have more power than you do now — until the show's a huge hit, if it is. Once you say yes, you're nowhere.' So he said, 'You have the most power right now, and it's all going to go away. So if you're going to make a stand, do it while you have some position of power.' "

If Garner was a mentor, Selleck's dad was his chief adviser all through his career. Though his father died in 2001, Selleck recalls a pivotal piece of advice.

"I remember being at USC and studying business and playing basketball. I'm in the management training program with United Airlines. Every vacation I'd work at the airport or in reservations. That would've put me ahead of the game if I went to work for them when I got out of school and I had to work to help support my education," says Selleck.

"I had an obligation to them. And lo and behold out of the blue I get offered — because I grew up in L.A. — a contract to the new talent program at 20th Century Fox. How can I quit my job? I went to my dad. He said, 'I think it's like your brother.' My brother, Bob, played with the Dodger organization. He said, 'There are certain things that are considered kind of special and a rare opportunity, and if you don't try them you don't want to be 35 having played it safe. I would look at it like your brother signing with the Dodgers, even though he had a college degree. It's an opportunity you might regret if you don't give it a try.' Then I knew how hard it was for him to give me this advice by what he said next, 'Just don't let them change you.' "

It never did. Married to his second wife for 20 years, Selleck has an 18-year old daughter and a grown stepson from his first marriage that he helped rear. Though he works consistently, he says he still worries about the mortgage. And he lives on a working ranch in the Thousand Oaks area of Southern California where you're likely to catch him clearing brush, mucking out the stalls or planting trees.

Sighing, he says, "I make 'Jesse Stone,' and people will argue whether it's any good. Reviewers will like it or they won't or they'll like the show but not me in it, and that'll make you nuts because we're really talking about an abstraction and other people's opinions. I plant a tree in a hole or build a chair I can sit in, or I can watch that tree grow. It's very good for your sanity 'cause you can get a little nuts in this business."