“It was such a beautiful, romantic thing,” recalls the ‘It Ends With Us’ star

Blake Lively says husband Ryan Reynolds went out of his way to be romantic back when they began dating.

The actress plays a flower shop owner named Lily Bloom in the new romantic drama It Ends With Us, and in an interview for this week’s issue, Lively describes to PEOPLE the best bouquet of flowers she ever received.

“When my husband and I first got together, he would send me a bouquet of flowers every week,” she says, “but he would always send a card and it would just be a sentence of something that had happened that week. Something funny or emotional that one of us said.”

“It was just a little quote of the week,” adds Lively, 36. “It was such a beautiful, romantic thing. Now we have 4,000 children!”

Lively shares four kids with Reynolds, 47, whom she married in 2012 after meeting each other as costars on the 2011 film Green Lantern.

Her It Ends With Us costar Jenny Slate, who shares a daughter with husband Ben Shattuck, also shared with PEOPLE about a memorable bouquet she recently received.

“My husband went outside with a gigantic basket and he picked all of these hydrangeas. And I like the hydrangea, it’s fine. But it was just so massive. It was like these clouds of hydrangeas,” says Slate, 42. “And he just brought them in the house just for beauty, just to give them to me.”

Slate, who plays Allysa, and Lively also discussed their bond after playing best friends in the new film, directed by their costar Justin Baldoni.

“My friends have consistently been my actual heroes because they’ve offered stability and light in times darkness or complication,” says Slate. “I’m so happy that aspect of the film has resonated, as I think it’s one of the driving forces of this project.”

“Getting to work with Blake and build that bond on this film is something I will always be grateful for,” the comedian continues. “Allysa and Lily have a true bond, human to human, and it’s been such a gift that Blake and I developed that as well. lucked out.”

It Ends With Us is in theaters Aug. 9.