I understand that in the commercial cultivation of Humulus lupulus, the newly sprouted bines are thinned to just one or two, which are then trained onto a support structure. However, what happens in a garden setting if the hops, growing at the base of their support, are not thinned and trained (basically in a no-maintenance context)? Will the bines indefinitely overgrow everything in their vicinity or just until they find the most direct path upwards?
Hops grow vigorously, so if you are planning to grow the twining bines untended and unpruned, you can expect them to cover a large area quite quickly (which is sometimes desirable, if you are attempting to disguise an unattractive structure in the landscape). If you want to grow them on an arch or other support, make sure it is sturdy. They will die back in the winter, and according to the American Horticultural Society’s Pruning & Training by Christopher Brickell (DK Publishing, 1996). the dead growth can be cut to the ground in early spring.
Brooklyn Botanic Garden says the following:
“Humulus lupulus, common hop: Flowers on new growth. Commercial growers cut their hop vines to the ground in late summer to harvest the cones. Hop vines grown for ornament should be cut to the ground in late winter to early spring. Root-prune to control underground runners.”
Fine Gardening has an online plant guide which describes a particular cultivar of Humulus lupulus:
Height: 15-30 feet
Growth habit: runs
Growth pace: fast (other sources say very fast)
Chicago Botanic Garden also has an informative article about Humulus. Here is an excerpt:
“Native to Europe and western Asia, Humulus lupulus is an attractive perennial vine suitable for Chicago-area gardens. During July, soft green conelike flowers known as strobiles emerge. Contrasting nicely with the foliage, these young flowers provide additional ornamental appeal. When the strobiles mature during mid- to late September, they can be collected for home brewing or other herbal uses.
Humulus japonicus, native to Japan and eastern China, is a vigorous annual vine that can easily become overgrown if not properly maintained. The strobiles of this species are useless for beer production, as well as herbal uses. The Japanese hop is best reserved for areas of the garden that simply require screening.
The vine is dioecious, meaning that male and female flowers occur on different plants. Female plants grown apart from males will still produce hops, but not seed, and the hops will weigh less.
Native to the Northern temperate region, hop vines can twine up to 25 feet in a single season, quickly filling in fences, bowers or arbors. The only physical features of the vine that may warrant consideration are the bristly spines surrounding each stem. They are only 1/8- to 1/4-inch in size and not as bothersome as one would think, but gloves should be worn for pruning or handling the vines.
With their smaller bristles, cultivated varieties of hop are favored by gardeners over the straight species. Humulus lupulus ‘Aureus’, or golden hop, is a cultivar with yellow foliage and a restrained growth habit that is suitable for smaller Landscape Gardens. As the vine begins its climb, golden, maple-like leaves emerge in spring. The light-green flowers complement the yellow foliage and add a unique bit of interest to the garden during late summer and early fall. Bright yellow foliage persists into late fall, blending attractively with fall-blooming asters and ornamental grasses that lighten as they approach dormancy.”