Idaho is a distinguished agricultural producer, known for its potatoes. Volcanic soil, a high-altitude climate, and abundant irrigation from mountain snowmelt create an ideal environment for growing high-quality tubers. Understanding the harvest involves examining a carefully timed process that ensures maximum quality and longevity. This schedule is precisely managed to coordinate with weather patterns and the specific needs of different potato varieties.
The Primary Harvest Window
The main potato harvest in Idaho, supplying the majority of the nation’s Russet potatoes, takes place during the autumn months. This primary harvest window begins in early September and continues through most of October, racing against winter weather. The most intense activity occurs during the last two weeks of September and the first two weeks of October.
The timing is driven by the need for the potato to mature fully while avoiding freezing conditions. Growers aim to harvest before the first hard freeze, usually striking in late October. The pulp temperature is precisely monitored at digging, ideally remaining between 45 and 65 degrees Fahrenheit. Maintaining this range minimizes bruising and prevents diseases like Pythium leak or pink rot during handling.
Timing Variations by Potato Type
While the Russet is the most iconic Idaho potato, the harvest schedule varies significantly by variety and intended market. The widely grown Russet Burbank, prized for its storage capability, is a late-maturing variety harvested from mid-September to mid-October. This late timing allows the potato to develop a thick, durable skin necessary for long-term storage and distribution.
Other Russet varieties, such as the Russet Norkotah, mature earlier and are often harvested from mid-August into mid-September. This earlier window also applies to fresh market potatoes like Reds and Golds, which are sold for immediate consumption. Early crops from western Idaho can be ready for harvest as early as the last week of July, with the main supply ramping up through August. The potato’s intended use dictates its specific harvest time.
Preparing Potatoes for Storage
Once potatoes are dug, a specialized post-harvest procedure prepares the crop for storage. The first step is curing, or suberization, which allows the potato to heal minor cuts or blemishes sustained during harvest. This phase involves holding the tubers at about 55 degrees Fahrenheit and 95% relative humidity for approximately 14 days.
This controlled environment encourages the formation of a protective layer of cork cells beneath the skin, preventing moisture loss and blocking pathogens. After the two-week curing period, the temperature is gradually lowered to the final long-term holding temperature, often at a rate of no more than half a degree Fahrenheit per day. The final storage temperature depends on the potato’s end-use: fresh market varieties are kept cooler (around 42 degrees Fahrenheit), while processing potatoes are held slightly warmer to maintain a low sugar content.