A trade council says an ongoing drought in South Africa will devastate the rooibos tea harvest, which may lead to a 90 percent price increase. The United States is one of the biggest importers.

The South African Rooibos Council said in a statement on Thursday that little rainfall during the July and August planting months could lead to the worst harvest in years. Drought conditions in recent years have also diminished reserves, despite farmers' efforts to adapt to a changing environment.

Council spokesman Ernest du Toit said farmers will only know the extent of their losses in 2016. Last year's rooibos harvest yielded 11,000 metric tons.

The council said rooibos tea is exported to more than 30 countries.

South Africa is the only region where the rooibos plant grows naturally.