I think I have white mold. My romaine was healthy one day and just keeled over in a dead wilt the next. First one. Then a couple of days later another. The rest of them are looking pretty sick. After some investigation, I've concluded the culprit is white mold. I'm just not seeing much help on the internet in terms of how to treat it other than crop rotation. Is there something else (in addition to crop rotation) I should do. And how long should I wait before I could plant any susceptible crops in this bed. And is there something I can do to keep this from happening in the future?

The romaine was planted in a small raised bed and I'm not using any chemicals.