Hemp is an amazing sustainable fabric! Probably one of the best sustainable textiles available.
It can be cultivated within 100 days.
First of all, hemp needs one third about the amount of water that cotton needs, and can produce two to three times more fiber than an acre of cotton. Already beating out organic cotton and most other textiles! Hemp doesn't need herbicides or pesticides to grow, and even detoxifies the soil while adding nitrogen and oxygen.
Hemp is hypoallergenic. It is also UV protected, antibacterial, breathable and absorbant.
So does it need GOTS?
In order to be GOTS Certified, a brand must meet the textile processing standard for organic fibers, including ecological and social criteria, backed up by an on-site inspection. The assessment is useful, but very expensive.
When crops are mass produced they can afford the GOTS inspectors to come out to certify their farming. However, even the large factories in China source their hemp fiber from many different small family-run farms. They don't source it all from one or two big farms. For this reason 100% hemp clothing cannot be GOTS Certified.
Hemp is always grown organically so you don't actually need to look for the GOTS certification when buying hemp clothing. This can be done so because hemp is not mass produced and is grown on many small family-run farms. GOTS certification is mainly used for cotton because cotton is such a mass-produced crop that without the certification it would be hard to know if the cotton clothing you are wearing is organic or not.