Kenyan flower farmer Jack Kneppers was forced on Monday to throw 6.5 tons of his exquisite roses into a compost pit after flights headed for Europe were canceled because of the ash cloud.

Kenya’s horticulture industry has already lost $12 million to the European airspace closure and it will take several weeks to recover even if flights resume now, its association of exporters said.

Kneppers’ farm by picturesque Lake Naivasha in southwest Kenya produces 11 varieties of pristine roses worth tens of thousands of dollars every day.

“We have to throw them into big pits and turn them into compost,” Kneppers said, standing in front of rows of boxes full of flowers that he fears will meet the same fate.