On Tuesday, during an appearance on The Late Show with Stephen Colbert, Davis, 56, broke down in tears while talking about her friend, who died of cancer at age 57 in September. She was joined by her And Just Like That… costar Cynthia Nixon to chat about the Sex and the City revival when Stephen Colbert asked about Garson.
Davis remembered Garson as "full of joy, and so incredibly brilliant and smart." She told Colbert, 57, that she and her And Just Like That… castmates initially did not know Garson was sick while filming the revival.
For more on And Just Like That… and other top stories, listen below to our daily podcast on PEOPLE Every Day.
"He still brought so much joy," Davis said, while Nixon, 55, explained that the cast and crew filmed with Garson "for a long time not knowing he was sick and then things got bad enough that we were informed."
"We're also very grateful that we had a few days with him knowing that he was sick, and we could talk to him about it and he could talk to us about it," Nixon continued. "And that was a really important thing for all of us."
Scott Kowalchyk/CBS Cynthia Nixon and Kristin Davis
Davis, who had been clutching Nixon's hand while discussing Garson's loss, choked up as she told Colbert, "It's hard."
"I wish he was here, you know?" she tearfully expressed.
The actress previously honored Garson shortly after his death, sharing photos of the late star on Instagram.
"I first met Willie in 1995 on the spooky nighttime set of the X-files," she began. "He immediately made me laugh. Little did I know that we would have the joy of sharing Sex and the City + And Just Like That together. Willie is beloved by our entire community. He was smarter and funnier than you ever would have imagined. We are bereft without him," Davis wrote.
Davis' emotional moment on The Late Show came not long after her costar Chris Noth opened up about his own experience working with Garson. In an interview published in The Guardian Monday, Noth, 67, also shared that most of the cast did not know about Garson's illness.
"Most of us didn't know," he said. "The last time I saw him was on set and I kick myself because I didn't really get a chance to talk to him. He was extraordinarily fun and funny and there's nothing to say but that it's heartbreaking."
Noth added, "It's sad for everyone, and for the show, because I think he was going to have a really huge storyline. But he'll be in it to the extent that he filmed."
"It's been unbearable," she began her caption. "Sometimes silence is a statement. Of the gravity. The anguish. The magnitude of the loss of a 30 + year friendship."
"Willie. I will miss everything about you. And replay our last moments together. I will re-read every text from your final days and put to pen our last calls. Your absence a crater that I will fill with blessing of these memories and all the ones that are still in recesses yet to surface," Parker added.
Garson starred as Sex and the City's Stanford Blatch — the best friend of Carrie Bradshaw (Parker) — and reprised his role in the revival, And Just Like That…. Garson died of pancreatic cancer after he had already filmed scenes for the upcoming series.
Because Garson's scenes for And Just Like That… were filmed prior to his death, his loss will not be included in the storyline, showrunner Michael Patrick King told The New York Times Friday.
"Nobody's dead," he said. "Because it wasn't charming. And I knew that the audience would know."