Harvesting Hemp Grain
You will know it is the right time to collect the seed if you can clap your hand a few times with a seed head removing around 40% of the total seed. Another indication for us has been the amount of Mourning Doves that inhabit the field and powerlines. You can use a regular bean head combine to target the upper 2-3 feet of seed head leaving behind the residual stalks. Recently we have changed our head from an auger to a drape for a steadier flow entering the feeder house. Also, we have found that swapping your concaves to have larger openings allows the seed heads to enter without wrapping up. The seed is harvested while it's still 20-25% moisture, which means you will want to get the grain on air immediately. Be sure not to use heat when drying your seed or you will cook out the seed oil. Keep your crop in your bin on air until it reaches 10% moisture. This process could take up to two weeks and could require re-elevation. Basically, just empty your bin into a couple of grain carts and refill it again with the air still on to help clean out some remaining debris.
Harvesting Hemp Fiber
This a 100-day crop planted in early May and harvested in September. During the vegetative state the stalks will grow tall and fast, making jumps in height weekly. Once the sunlight gets to a certain number of hours per day your plants will change to a reproductive mode. At that point your field may only get another 1-2 feet taller. You will want to harvest before the seed has reached full maturity. The best way to monitor your field is by looking at your fiber development. Cut a stalk into 18-inch sections paying attention to the air space in the center. As the plant matures the center will fill out with hurd resulting in greater tonnage. You can harvest with a sickle bar or swather (With Crimpers Spread) to cut down the stalks. Be sure to leave 6 inches of stalk to protect your tires and for creating a bed of air for the stalks to rest on. The stalks will need to remain in the field for 2 weeks to begin a process called retting. During this retting process the stalks will get wet at night and dry during the day naturally removing lignin in the outer fiber. After two weeks you can come through with a rake to move the stalks into rows. After Raking you will need to leave the rows in place for another two weeks. Now that the retting process has completed, you can come through with a round or square baler.