A boat?

Unfortunately riddled with worm, this seed tray is almost 60 years old.  Back then D.'s dad (giga serious gardener) bought seed tray components flat pack by the gross and made up trays as needed.  At least that was so when D. and her younger sister had not swiped the handy small pieces of wood for boat building.  On another occasion D. took his change from his dressing table and, after digging up the recently planted seed potatoes, planted quite a lot of it before he noticed:  moral  may be not to ask children if they think money grows on trees.