Although peppermint grows easily in Oregon it has its problems, like most crops, when cultivated on a large scale. Butler Farms wages a continuous battle with pests--everything from spider mites, cutworm, crane fly and nemotodes to symphylans, mint rust and verticillium wilt. One year, they lost 25 percent of their peppermint crop to mint rust. Mint rust, a fungus that blisters and destroys mint leaves, took Butler Farms from profitable to breakeven in one short week.
In other words, says Butler, “You don’t just throw it out there and hope for the best, because there wouldn’t be much.”
In the Willamette Valley, peppermint is perennial. It awakens from its winter dormancy in late January to early February. At that point, Tim Butler goes out into his fields with a winter herbicide spray to keep the weeds at bay.
By the first of March, the peppermint shoots are visible and growing quickly but Butler’s first fertilizer and fungicide applications don’t happen until several weeks later in mid-April. Butler then crosses his fingers, hoping that insecticide application isn’t necessary.
Throughout the year the Butlers monitor their fields with integrated pest management. An agronomy professional scouts the farm testing for nemotodes and other detrimental insects. Depending on the results, some fields get insecticide application while others don’t.
From April on, the peppermint is hungry and thirsty as it grows at breakneck speed. In the summer it’s irrigated with roughly an inch to an inch and a half of water weekly and fertilized heavily as well.
Early-to-mid-August at Butler Farms means peppermint harvest. They swath it, put it in rows, chop it, and pick it up with a harvester (similar to alfalfa, clover and corn harvest). From the field the mint goes into eight- to nine-ton mint hay tubs which are taken to the mint still by truck.
Stay tuned for the next two installments of this story.