Hops (Humulus lupulus) is a perennial climbing vine known for its ornamental beauty and the cones used to flavor beer. Successful cultivation begins with properly planting the rhizome, which is the underground stem cutting used for propagation. The timing of this initial planting significantly determines the plant’s establishment and subsequent growing seasons.
Determining the Ideal Planting Window
The most advantageous time to plant hops rhizomes is in the early spring, coinciding with the end of the deep dormancy period. This timing depends on local weather and is best determined by specific climatic indicators rather than fixed calendar dates. The primary sign to look for is “workable” soil, meaning the ground is thawed and no longer muddy or saturated from winter precipitation.
Soil temperature provides a more precise measurement for optimal planting, ideally aiming for a range of 45 to 50°F (7 to 10°C). Planting should only occur once the danger of a hard, sustained freeze has fully passed, although the rhizomes themselves are fairly hardy. Introducing the dormant rhizome to warming soil allows it to begin developing its root system without the stress of rapid shoot growth.
Rhizomes are typically shipped while dormant in late winter or early spring and must be kept cool and moist until the ground is ready. If planting must be delayed, storing them in a plastic bag with slight moisture in a refrigerator is an effective short-term method to maintain dormancy. In colder climates where the ground thaws late, some growers pot the rhizomes indoors for a few weeks to give them a head start before transplanting outside in late spring.
Preparing the Soil and Rhizomes
Proper site and soil preparation is important, as the first year of growth focuses on establishing an extensive root system. Hops thrive in deep, well-draining soil, such as a sandy or silt-loam, to prevent the rootstock from rotting due to standing water. If the native soil is heavy clay, amending it with organic material like compost or well-rotted manure will significantly improve drainage and structure.
The soil should be worked into a fine, mellow consistency and cleared of weeds before planting. Hops prefer a slightly acidic to neutral soil pH, with an ideal range between 6.0 and 7.5, which optimizes nutrient availability. Before planting, inspect the rhizomes upon arrival to ensure they are firm and free of damage.
If the rhizomes appear dry from shipping, they can be rehydrated by soaking them in water for a few hours immediately before planting. Excessive or prolonged soaking should be avoided, however, as this can lead to rot. The goal is to keep the material moist but not saturated while awaiting placement in the prepared soil.
Step-by-Step Planting Instructions
The planting location should receive a minimum of six to eight hours of direct sunlight daily, as hops require full sun exposure. The planting site must also accommodate a strong support system, since the bines can grow up to 25 feet in a single season. This support structure, such as a trellis or sturdy twine, must be ready to accommodate the rapid vertical growth.
To plant the rhizome, dig a hole or trench approximately two to four inches deep and wide enough to accommodate the cutting. The rhizome is typically about six inches long and should be planted horizontally. If discernible buds or shoots are present, they should be oriented to face upwards toward the soil surface, but horizontal planting is acceptable if the buds are indistinct.
The rhizome is then covered with loose soil and lightly packed to ensure good contact with the surrounding earth. If planting multiple rhizomes, space them at least three feet apart for the same variety and up to five feet apart for different varieties to prevent competition. Creating a small mound of soil over the planted rhizome, sometimes called a “hill,” helps protect the crown.
Initial Care After Planting
Immediately following planting, the rhizome must be thoroughly watered to settle the soil around the cutting and initiate growth. Since the first year is dedicated primarily to root development, consistent moisture is necessary for establishment. The soil should be kept moist but must never be allowed to become waterlogged, as this can cause the rhizome to rot.
Applying a layer of organic mulch, such as straw or wood chips, over the planting area helps retain soil moisture and suppresses competing weeds. This moisture management is important in the first few weeks before the plant develops an extensive root system. Frequent, light watering is recommended for first-year hops, rather than infrequent, deep saturation.
The first shoots should begin to emerge above the soil surface within a few weeks. Once the young bines reach about one foot in length, two or three of the most vigorous shoots should be selected for training onto the support structure. Remove the remaining shoots to concentrate the plant’s energy into the selected bines, which must be gently wrapped clockwise around the support to encourage their upward climb.