Wheat is a major global crop, and its harvest is a complex, year-round process in the United States. Determining the exact time for harvest is not a single date but rather a dynamic decision based on the specific variety planted and the local climate conditions. The timing of this harvest directly impacts the final quality, nutritional value, and overall yield of the grain. This schedule is governed by two distinct growing cycles and progresses geographically across the country’s diverse agricultural regions.
The Two Primary Wheat Cycles
The timeline for wheat harvest depends on the two major types grown in the U.S.: winter wheat and spring wheat. Winter wheat, which accounts for 70 to 80 percent of the total production, is planted in the fall, typically between September and October. This allows the plant to develop a strong root system before the cold weather sets in, entering a period of dormancy during the winter months.
It resumes growth in the spring and is harvested in the late spring and early summer of the following year. Spring wheat follows a different schedule, planted in the early spring, usually in April and May, as soon as the soil is warm enough to work.
This variety grows over the summer months and is harvested later in the year, typically in the late summer or early fall. This dual-cycle approach means that wheat is harvested almost continuously somewhere in the country from late spring through early autumn.
Geographic Harvest Timing in the US
The wheat harvest follows a northward progression across the country. This begins with the Southern Plains, where harvest of the winter wheat crop can start as early as late April to early May in Texas, moving through Oklahoma by late May.
The harvest then moves into the Central Plains, with Kansas, the nation’s largest wheat-producing state, beginning in early to mid-June and continuing through mid-July. By July, the combines are active in states like Colorado and Nebraska. This winter wheat movement concludes in the Northern Plains by late July and August.
The later summer months are dominated by the spring wheat harvest in the upper midwest and Pacific Northwest. States like North Dakota and Montana plant their spring wheat in cooler conditions and harvest it from August into September. The Pacific Northwest, including parts of Idaho and Washington, also sees its harvest occurring from July through September, depending on the specific location and class of wheat grown.
Indicators of Readiness
Farmers rely on specific physiological indicators to decide the exact day to begin harvesting. Readiness begins with physiological maturity, which occurs when the kernel ceases to accumulate dry matter, often around 30 to 35 percent moisture content. At this point, the plant’s straw begins to turn from green to a golden or yellow color.
The grain’s moisture content is the most important factor, as it must fall within a specific range for safe storage and marketability. The ideal moisture content at harvest is between 18 and 20 percent, allowing the farmer to get the crop off the field quickly to avoid weather damage. The grain then continues to dry down in the field at a rate of roughly 2 to 3 percent per day. For immediate sale or long-term storage, the grain must be dried to a target moisture level of around 13.5 percent or lower to prevent spoilage from mold and insect damage.
The Harvesting Process and Equipment
Harvesting is carried out almost entirely by the modern combine harvester. This machine performs the multiple tasks of cutting, threshing, separating, and cleaning the grain in a single pass. The combine’s header at the front cuts the wheat stalks and feeds them into the machine.
Inside the machine, the threshing drum or rotor separates the grain kernels from the heads using impact and friction. The clean grain is then moved into an onboard storage tank, while the remaining straw and chaff are expelled onto the field. Due to the requirement for low moisture content, the harvest process must be executed quickly and ideally during dry weather conditions.