It is narrated from Sayyiduna Abdullah bin al-Zubayr (may Allah be pleased with him) that he said: "The Prophet (peace and blessings be upon him) ordered his uncle Abbas (may Allah be pleased with him) to order his sons to cultivate 'qadb', for it drives away poverty and hardship."
The narrator said: By qadb is meant ratbah (fresh green fodder).
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13878