Did any warship carry grass on its deck?

Was there ever a warship on which the crew planned to grow grass on the deck?

Not as a planned design feature, but grass did grow on some Dutch vessels while they were escaping Japanese forces.

No warship deliberately designed to grow grass on deck is identified. Grass did, however, end up growing on Dutch vessels during their escape from Japanese forces. The passage names no particular ship and does not claim that the vegetation was an intentional camouflage scheme, so this remains a brief pointer rather than a complete case history. Even with that limit, the example shows how wartime flight could leave a warship looking far removed from its intended peacetime condition.