Crown buds can be protected in several ways as you prepare you hop yard for winter.  First, leave the hop bines cut at 24 to 36 inches high over the winter. The old bines supply extra sugars to the crowns and act like little snow fences; slowing the wind, holding snow and field debris around the crowns.  Second,  physically cover the young crowns - protective mulches or field soil 1 to two inches deep is a typical field practice.  Third,  apply a high potassium fertilizer in the fall to winterize the hop plants.  Hop yards with low potassium levels experience higher levels of winter crown bud damage. A close placement of granular or dissolved through the drip system is necessary for it to be effective; since the fine feeder root mat formed during the growing season is breaking down and disappearing.  The potassium ion prevents ice crystals from forming in the plant tissues and allows water movement at lower temperature ranges. (Think of potassium as anti-freeze for your hops!)