If I am not mistaken I believe it is true.
It was rocky soil, treed mountains.
So they couldn't really grow anything.
The Hindu Kush
The Hindu Kush (Pashto: هندوکش /kʊʃ, kuːʃ/) is an 800-kilometre-long (500 mi) mountain range in Central and South Asia to the west of the Himalayas that stretches from central Afghanistan into far northern Pakistan and far southern Tajikistan.