The common hop, Humulus lupulus, is a perennial plant famous for providing the bitterness, aroma, and flavor in beer. These vigorous climbers produce annual shoots that emerge from a permanent underground root structure called a rhizome. Hops are one of the fastest-growing plants in cultivation, seeking vertical support to maximize their exposure to sunlight. The plant’s rapid ascent allows it to achieve impressive heights, which is a necessary condition for a successful harvest.
The Maximum Vertical Reach
Hops are known for their exceptional vertical growth, which must be accommodated by a support structure to realize the plant’s full potential. Under ideal conditions, a healthy hop plant is capable of reaching heights between 20 and 30 feet in a single growing season. The height is entirely dependent on the availability of vertical support, as the plant will grow until it reaches the end of its structure or the summer solstice.
Commercial growers typically utilize trellis systems that are 18 to 20 feet high. This established height is what most commercial varieties are bred to fill before they transition to the lateral growth that produces the hop cones. While backyard growers may not erect structures this tall, the plant maintains the genetic potential for this substantial vertical reach. This rapid growth phase occurs in the spring and early summer before the plant shifts energy toward reproduction.
Understanding the Hops Growth Habit
The ability of Humulus lupulus to climb to such heights is due to its unique botanical structure, which is correctly termed a “bine,” not a vine. Unlike true vines, which use specialized structures like tendrils or suckers to attach themselves to surfaces, the hop bine climbs by twining its entire stem around a support. This twining is facilitated by stiff, coarse, downward-pointing hairs, known as trichomes, that line the stem and hook onto the support structure.
During the peak growing season, the speed of vertical ascent is remarkable. Hops can grow anywhere from 4 to 12 inches per day, with some varieties reportedly growing up to one foot in a 24-hour period. The bines consistently rotate in a clockwise direction as they climb, following the sun’s path across the sky. This inherent rotational pattern dictates how the plant must be trained onto its support structure for optimal growth and stability.
Cultivation Factors that Influence Height
A hop plant must receive specific environmental inputs to achieve its maximum vertical growth potential. Sunlight exposure is a major factor, as the plant requires at least six to eight hours of direct sun daily to fuel its rapid growth. This need for light is why commercial production often takes place in latitudes that offer long daylight hours during the summer.
The soil composition and nutrient availability also influence the plant’s final height. Hops perform best in deep, well-drained, sandy loam soils with a slightly acidic pH range of 6.0 to 7.0. Adequate fertilization (including nitrogen, phosphorus, and potassium) is necessary to support the vegetative growth produced annually. Consistent water is required, especially during the spring growth spurt, because the plant’s large leaf area transpires significant moisture.
Plant genetics play a role, as different cultivars have varying growth characteristics. Certain high-alpha acid varieties are vigorous and tall, while other aroma varieties may have a shorter stature. Disease or insect pressure can also stunt growth, preventing the bines from reaching the typical 20-foot ceiling.
Managing Vertical Growth
Achieving maximum vertical growth necessitates providing a strong trellis system capable of supporting the mature plant’s substantial weight. Commercial operations use high-tensile wire strung between tall poles, which provides the necessary anchors for the climbing strings. This system maximizes the yield surface area.
For each plant, growers select and “train” two to four of the most vigorous bines onto the support string early in the season, typically when the shoots are about two feet long. The remaining shoots are pruned away to concentrate the plant’s energy into the selected bines, promoting vertical growth. Backyard growers often use heavy twine, rope, or cable strung from a flagpole, arbor, or eave, mimicking the commercial system on a smaller scale.
The vertical support must be sturdy enough to bear the weight of the mature bines, which can weigh over 20 pounds per plant. Once the bines reach the top of the support, they transition to growing horizontally, producing the lateral branches where the hop cones will form. The lower two to three feet of foliage on the main stem is often stripped to promote air circulation and reduce the chance of disease near the ground.