In hop-producing countries outside the United States, it is common for farmers to run sheep through their hopyards for weed control, to control sucker regrowth, and for the small addition of manure for soil fertility benefits. In New Zealand, for example, hops are an integral part of both certified organic and conventional hop production.

While sheep are commonly used in other countries, many hop growers have wondered if there are certain rules that must be followed for sheep to be included in Michigan hopyard management. For conventional hop growers, there are no rules preventing sheep from being included in a hopyard management plan. However, the rules differ for organic production. Current USDA Organic regulations require a 90-day period between manure application and crop harvest if the crop does not come in contact with the soil, and 120 days if the crop does come in contact with the soil. 

However, certified organic hop growers are encouraged to speak with their organic certifier, since there are cases in Michigan where organic growers have been allowed to use sheep in hopyards. If sheep are used, hop growers are advised to be cautious using copper-based disease control products because they are toxic to sheep.

While sheep are currently allowed, in 2015 the FDA is expected to release its second version of the Food Safety Modernization Act (FSMA) proposed rule. Indications are that sheep will still be allowed, but it remains a matter of interpretation. According to an Emerging Issues Specialist at the Michigan Department of Agriculture and Rural Development, hops are not specifically called out as being exempt in the proposed rule, but there are two exemptions they could fall under. The first is, “produce that is rarely consumed raw.” While hops are not on this list, it is conceivable that they may fall into this designation. The second is, “produce that receives commercial processing that adequately reduces the presence of microorganisms of public health significance.” Hops may fall under this classification as well.

If hops are determined not to be exempt, hop farmers may still be able to include sheep throughout the growing season since the proposed rule states that if manure application is done in a manner that does not contact covered produce during or after application, then there is not a required time interval.

Since weed control is one of the major challenges in hop production, and sheep offer a natural solution to this issue, we will keep farmers up to date on the next release of the FSMA proposed rule. Please continue to visit Michigan State University Extension’s hop webpage or the MSU Hops News Facebook site for up-to-date information.