Even after all that experience, True Blood and its swampy Louisiana setting still proved to be a special treat for Helmond.
"I was so pleased when they sent me the script," she says on the phone from her home in Los Angeles. "It's a subject I love to read about because I come from that Gulf Coast area.
"I grew up hearing about the walking undead. I had a fascination with it as a child."
Helmond is a native of Galveston, Texas. "Sometimes it would rain 15 days in a row," she says. "We'd have to move all the furniture up to the second floor in case of flooding."
(We won't be so uncouth as to reveal a lady's age. Let's just say she came into this world the same year Mickey Mouse made his screen debut in Steamboat Willie.)
The conditions on the True Blood set in Hollywood, Fla., where she shot her first episode as Portia and Andy's grandmother, Caroline Bellefleur, also brought back childhood memories.
"The humidity is beyond belief. You just cannot go outside," she says. "All the actresses are given parasols so when you went into the sun, it wouldn't affect the makeup. I think they want all the actresses to be very pale anyway."
Vampires aren't the only ones who have to worry about sun exposure. Southern belles are delicate creatures, too.
A successful stage actress, Helmond was thrown by her first TV experience in 1962, in an episode of Car 54, Where Are You?, the classic sitcom starring Joe E. Ross and Fred Gwynne.
"They shot the last scene of the piece the first day I got to the set," she says. "It was all out of sequence. I thought 'Good heavens, no wonder it's a mess.'
"I still feel that way. When I go to work and then see the piece on TV, I think, 'By gosh, they got it all put together!' It's still magic to me."
Of all her roles, Helmond says she is most associated with the loony matriarch Jessica Tate on the cult '70s parody Soap.
The part was a departure for her.
"When I first came out here [to Los Angeles]," she says, "I played weeping ladies and much put-upon women. A director recommended me for the role on Soap. They said, 'She plays heavy roles, murderesses and the like.' He said, 'On stage, she could be very very funny.' "
With Soap, her career took an unexpected Leslie Nielsen-like turn into the absurd.
"What happens in Hollywood," she says, "is that if you get a heavy part, you're stuck in that kind of role. If someone takes a chance and let's you play funny, then they say, 'But can she be serious?' It's like the last part you did is the only thing you can do."
Obviously, with a resumé as varied and deep as Helmond's, there's nothing she can't do.
She attributes her constant employment to - you guessed it - her childhood.
"I went to Catholic school. Do as you're told; don't ask questions and you will be illuminated," she says, laughing.
That discipline has stood her in good stead on countless sound stages. "I listened; I paid attention, and I sat quietly in my chair until they pointed at me. Then I got up and did what I was expected to do.
"When I got to be an old girl, I was still a good little girl."
Which explains why she has been so often illuminated.
Contact David Hiltbrand at 215-854-4552 or email@example.com. Read his pop-culture blog at www.philly.com/dod.