The TV drama is coming to an end next year after eight series and the actress - who has played perfectionist Bree Van de Kamp since the beginning - admits it will be a chance for her to dedicate her time to her four-year-old twins, Eden and Savannah.
She said: "It's a heavy workload as a desperate housewife! Now the twins can speak, they want to know where I'm going and are like, 'Don't go! When are you going to be home?' I try to explain a bit about how the show is ending.
"I think the minute we wrap, I'll become a hands-on mom, because I know I won't want to do it forever. Once kindergarten starts, I know I'll be like, 'Here I am everybody!' That's when I think I'm going to get the itch to get back to work."
Marcia, 49, also says she'll be able to spend more time with her friends once the show ends.
She told Closer magazine: "But it's not time with my kids that I've given up for 'Housewives', it's time with my friends I've neglected. Thankfully they're not gone."