The common hop, Humulus lupulus, is a perennial climbing plant known for its exceptionally rapid growth. Hops are famously used in beer, where the female flower cones provide bitterness and aroma. Each autumn, the plant dies back to a cold-hardy root structure, sending up vigorous new shoots every spring. This cycle of yearly dieback and explosive regrowth allows it to quickly achieve significant height. The speed at which hops grow changes dramatically between the plant’s first year and its mature phase.
The First Year: Focusing on Root Establishment
The initial growing season for a newly planted hop rhizome is primarily dedicated to underground development rather than vertical reach. The first year’s slow pace is an investment in future productivity, as the plant focuses its energy on establishing a strong, deep root system, or crown, which can eventually penetrate the soil to a depth of 15 feet or more.
This focus means above-ground growth remains modest compared to later years. A first-year plant may only reach a height of six to eight feet, significantly shorter than its mature potential. While it produces foliage, the yield of female cones will be minimal. Growers are advised to leave all the greenery during this stage to maximize the photosynthesis needed to fuel root development for the following season.
Measuring the Mature Growth Rate
Once the root system is established, typically in the second or third year, the hop plant enters the mature phase. The plant’s annual shoots, termed “bines,” exhibit one of the fastest growth rates in the plant kingdom. This speed is enabled by the vast energy reserves stored in the root crown.
During the peak growing season in late spring and early summer, a mature hop bine can grow between six inches and one foot per day. This astonishing rate allows the bines to quickly ascend support structures. Unlike a vine, which uses tendrils to climb, a hop bine uses stiff, hooked hairs, or trichomes, on its stem to spiral clockwise up the support structure.
Mature bines rapidly climb to their full potential height, often reaching 18 to 25 feet by the end of June, when vertical growth ceases. This height requirement means providing tall, sturdy support, such as a coir or string trellis, is essential. The process of “training” involves selecting a few of the strongest bines to guide onto the support structure early in the season, ensuring optimal growth and light exposure.
Environmental Conditions That Accelerate or Slow Growth
The growth rate of a mature hop plant is highly dependent on ideal environmental inputs. Sunlight is a primary accelerator; plants require at least six to eight hours of direct sun daily to maximize vegetative growth and cone production. Hops thrive in temperate climates that provide long daylight hours during the growing season, which triggers cone development.
Consistent and deep watering directly influences growth speed, especially during rapid vertical ascent. Hops require ample moisture but are highly sensitive to standing water, which can lead to root rot. Well-drained, deep, sandy loam soils are preferred because they balance moisture retention with necessary drainage.
Soil fertility, particularly nitrogen availability, is important for supporting the large volume of vegetative growth. Mature plants require significant nitrogen to fuel the daily growth of up to a foot. Regular soil testing and amending with nutrients ensures the plant has the resources to achieve maximum speed and yield. Additionally, the plant requires a period of cold dormancy, with temperatures below 40°F for one to two months, which resets the crown for vigorous regrowth the following spring.