Because field-grown vegetables at the seedling stage are highly vulnerable to weed competition, weeds must be removed early in the crop cycle to prevent yield losses. But weed control proves challenging for many growers because farm labor is often in short supply and effective vegetable herbicides sometimes aren’t available. These challenges have sparked interest in intelligent weeders — autonomous machines that remove weeds while leaving crops unharmed. But intelligent weeders often struggle to differentiate weeds from vegetable crops. This challenge might be overcome through crop signaling, a technique that allows target crops to be identified rapidly and accurately.