Get ready, DC Comics fans — CW is planning an epic four-show crossover event in the fall.

Now that “Supergirl” has moved into CW’s turf, the network has a four stack of DC-branded heroes on its air this fall, with Kara Zor-El’s adventures joining “The Flash,” “Arrow” and “DC’s Legends of Tomorrow.”

CW president Mark Pedowitz wouldn’t divulge any details other than to promise that planning is under way. In a conference call with reporters Thursday in advance of the network’s upfront presentation, Pedowitz expressed his confidence that producers, led by uber-exec producer Greg Berlanti, will ensure that “our annual crossover event this fall (will) be the biggest one ever.”

Pedowitz also joked about the potential for “Supergirl” to interact with her Monday night neighbor “Jane the Virgin.” “Just imagine what our superhero crossover episodes are going to look like come December,” he said.

Pedowitz said the discussions with CBS and Warner Bros. TV about moving “Supergirl” from CBS for its second season only began about a week and a half ago. He asserted that the CW is “where it should have been in the first place.” CW is projecting that “Supergirl” will be among its top three most-watched series, as it will bring some viewers along from CBS while reaching much deeper into the CW’s younger demos.

As for creative changes to the show with the move, Pedowitz said there wasn’t much of a new mandate for producers. With the show moving production to Vancouver to shave off some of the production budget, there was speculation that Calista Flockhart would not continue in her supporting role.

“I don’t think (the move) will have a major effect on how they actualize what they do,” he said. Pedowitz said discussions were in progress with Flockhart, who wants to continue with the series.

Pedowitz was also pressed on the status of “The Vampire Diaries,” which is heading into its eighth season. Pedowitz said there was no decision yet on whether the next go-round will be the last for the workhorse supernatural drama, nor has there been a decision on the number of episodes for season eight. “We’ll see how the audience reacts,” he said.

And it wouldn’t be a CW newser without Pedowitz facing the eternal question: wither a “Supernatural” spinoff? Pedowitz said there was nothing on the horizon at present but with a caveat that is sure to keep hope alive for the super-fans: “We’re open to listening,” he said.