How to Divide Hop Plants
A vigorous herbaceous vine, hops (Humulus lupulus) were introduced from Europe into North America in the 1620s. The plant grows best in a sandy loam that is moist, well-drained and rich in organic matter. Sometimes hops are referred to as a "bines" since the stems spiral around supports in a clockwise fashion.
Winter frosts kill back the stems to the ground and the large, woody rhizomes and roots overwinter to re-sprout the next spring. Grow hops in U.S. Department of Agriculture hardiness zones 4 through 8 where summers are not too hot.
Divide hops plants in early spring just before the first sprouts of growth emerge from the ground. In mild winter regions with few frosts, dig and divide hops from late fall to early spring, as long as the soil is workable and free from frost.
Pierce the soil around the hops plant with a sturdy, sharp-bladed garden shovel. The rhizomes are woody and tough, so expect to use the full force of your legs and body weight to sever radiating roots around the central clump of rhizomes. Chop into the soil around the root mass with a hatchet if you have trouble directing the shovel blade into the ground.
Remove all soil around the mass of roots and rhizomes of the hops plant. Lift the mass from the hole and examine it. Look for rhizomes that are over 6 inches in length and have at least one "eye" or growing buds. These rhizomes are worth keeping and are the focus of your clump dividing.
Slice into the root mass with the garden shovel, hatchet or hand pruners to obtain at least two healthy rhizomes with eyes. In some cases, a bisecting cut across the core of the root ball can yield a matrix of rhizomes for immediately replanting to create two new hops plants.
Replant the rhizomes immediately, orienting the roots so they sit in the planting hole just like they did when you initially dug them up. The buds are always oriented upwards according to the Oregon Hop Commission. The eyes of the rhizomes are covered with exactly 1 inch of soil.