Growing hops at home for brewing or ornamental purposes can be quite rewarding. However, consistently producing healthy hop plants with good cone yields is a bit of an art, but with experience, it is a process that can be mastered by following a few easy steps.
Hops (Humulus lupulus) is a perennial in the hemp family (Cannabaceae) that produces annual bines from overwintering rootstock. Hops are native to Europe, western Asia, and North America and are one of the key bittering and flavoring ingredients of beer.
Hops are described as “bines” rather than “vines” because they climb by wrapping around a supporting structure in a clockwise direction and cling to the surface using stiff downward-facing hairs.
Hop plants are dioecious; they have separate male and female plants. Only the female plant produces the cones and lupulin utilized in brewing. Lupulin is a yellow, resinous substance produced by specialized glands within the cones. Lupulin contains the oils and resins that give hops their distinct aroma. Hops are rhizomes that have underground stems that can produce additional roots and shoots.
Step 1. Selection and Propagation
Cascade, Chinook, Nugget and CTZ varieties will grow well on the Colorado Front Range. Nugget and Chinook varieties are prolific growers and are very resistant to both insect pressure and diseases. Rhizomes can be purchased from some homebrew stores, through mail order from many growers, or by propagating established plants.
In Colorado, rhizomes should be divided in late February to early March while plants are dormant. If possible, untrained bines should be coiled around the base of the plant during the growing season and covered with soil. The covered bines will convert to rhizomes, which can be removed in the winter by digging adjacent to the plant and cutting the rhizomes from the plant using a sharp, sterile knife. Ideally, cut the rhizomes into approximately 3-inch lengths with multiple buds.
Stem cuttings can be taken throughout the growing season but are more likely to root when obtained in the spring through early summer before flowering. Several cuttings can be taken from one bine. Dissect the bine so that each cutting has one node at the top, dip the stem bottom in a root toner, and place the cuttings in sand or florist’s fam. Keep the rooting media wet, and roots should develop within 2 weeks. Once roots are well formed, transplant the cutting into a pot with soil and fertilize with a basic fertilizer such as 16-16-16.
Step 2. Establishment and Care
Hop bines normally grow from 15 to 20 feet high but may grow higher depending on the climate and available climbing support. They require full sun (12 hours), good air circulation and well-drained soil with a pH between 6 and 7.5 for high productivity. A large container such as a half whiskey barrel can also be used and allows you to manage your soil conditions and help keep any unwanted spreading of the rhizomes into your yard.
Once the threat of a killing frost has passed in the spring, transplant the hops into the desired outdoor site. Dig a narrow trench 12 inches deep and slightly longer than the rhizome. Plant one rhizome per hill with the buds pointed up and over with 1 inch of loose soil. They should be spaced three feet apart. Initially, provide consistent watering while being careful to not over water because hops do not like to have “wet feet”.
After establishment, provide climbing support such as a pole or trellis at the planting site. Ideally, string a top wire about 15 to 18 feet high, then attach strings the hops will climb. As an alternative, erect a single pole, which is what most commercial yards did until well into the nineteenth century, and run strings to the top. The string needs to support plants that will weigh 20 lbs when mature. If planting two or more hop plants side by side, allow 24 to 36 inches of spacing between plants. If growing for ornamental reasons, a standard trellis or arbor can also work and keep bines pruned to keep desired form. The cones will grow on sidearms as the plant grows.
The focus in the first year of planting is root establishment and not cone production, thus it may be beneficial to limit the plant’s ability to climb during establishment by supplying only a 4-foot stake or pole. Be careful not to remove foliage during the first year because the plants require as much leaf material as possible to develop and store carbohydrates in the root system for the following year’s growth. Plants usually reach full production in their second or third growing season.
Step 3. Train the Bines
As the shoots grow to approximately 3 feet in length, choose the 2-3 most vigorous to grow and remove all remaining shoots. As the shoots elongate, train them onto the support structure by winding them in a clockwise direction, which follows their natural growth habit. Plants may be fertilized during spring and early summer, but fertilizer is not typically required after mid-July. Nitrogen is usually the limiting nutrient for adequate hop growth. You can apply nitrogen as urea (46-0-0) or in combination with other nutrients such as a 16-16-16 fertilizer.
Step 4. Irrigation
Hop plants require consistent moisture throughout the growing season. The plant roots want to be wet but not waterlogged. You may let the soil dry out slightly between waterings. Hop plants grow very rapidly during the heat of summer, so it is important to deliver consistent, even moisture to prevent drought stress. A hop plant may require several gallons of water per day during the summer. Water at the base of the plant to minimize wet foliage which can lead to disease issue.
Step 5. Common Diseases and Insects
Powdery mildew is a common disease affecting hops in our climate. It is caused by the fungus Podosphaera macularis. Although unsightly on the foliage, powdery mildew is most problematic when it attacks developing cones during the summer. Cone tissue infected with powdery mildew becomes necrotic and deformed, and chemical composition may be negatively affected. Control measures include spring pruning to remove infected tissue and fungicide application with products such as sulfur. Many varieties of hops, such as Nugget or Chinook are resistant to the disease.
Spider mites are a common insect problem. A minor infestation causes bronze leaves, while a severe one results in defoliation and white webs. Spider mites are most dangerous during warm dry weather and not usually a problem for well-watered plants.
Step 6. Harvesting and Storage
Hops typically mature between mid-August and mid-September. Hop cones harvested for beer brewing can be used fresh after picking, or dried and sealed in an airtight container in the freezer for later use. Mature cones will have a dry, papery feel, and the lupulin inside of the cone will be golden yellow and have a pleasant “hoppy” aroma. Immature cones will feel soft and vegetative, and the lupulin will be pale yellow with a mild vegetative aroma.
After harvest, cut the bines off the trellis leaving 2 feet of bine above ground. Do not cut down the last green matter until after the first frost, then prune bines to a few inches and cover with mulch.
Hieronymus, S. (2012). For the love of hops: the practical guide to aroma, bitterness and the culture of hops. Boulder (Colorado): Brewers Publications.
Growing Hops in the Home Garden: https://catalog.extension.oregonstate.edu/em9115
Powdery Mildew Fact Sheet: https://extension.colostate.edu/topic-areas/yard-garden/powdery-mildews-2-902/
Aphids on Shade Trees and Ornamentals: https://extension.colostate.edu/topic-areas/insects/aphids-on-shade-trees-and-ornamentals-5-511/
Spider Mites: https://extension.colostate.edu/topic-areas/insects/spider-mites-5-507/
Organic Hops Variety Trials and Over-wintering Study: https://specialtycrops.agsci.colostate.edu/organic-hops-variety-trials-and-over-wintering-study/
Written by Kevin Ritter, a Denver County Master Gardener as well as Crooked Stave Artisan Beer Project’s Laboratory Technician and Sensory Specialist.
Photos courtesy of Pixabay.com, a source for royalty free images