A product display merchandiser includes a tray having a product-supporting surface; a base plate situated below the tray; and a sidewall subassembly coupled to the tray and the base plate. The sidewall subassembly has a first sidewall adjacent a first lateral side of the tray and a second sidewall adjacent a second lateral side of the tray. Each of the first and second sidewalls has a vertical portion and a horizontally projecting tab. A portion of the horizontally projecting tab of the first sidewall slidably interfaces with a portion of the horizontally projecting tab of the second sidewall such that the vertical portions of the first and second sidewalls are laterally adjustable relative to one another and the base plate.