Oregon Hop Commission - Oregon Hop Farming

Oregon hop farming has a rich historical background, with many of the farms being passed down through families from generation to generation.   A majority of Oregon hop growers are third or fourth generation growers with an average farm size of 200 acres.  The growing region is extremely concentrated, experiencing little difference in growing conditions between the northern and southern-most growers, and likewise for the eastern and western-most growers.

• Hops are usually propagated from rhizome cuttings, also known as rootstock, and are planted in the spring (image). 
• Soil samples are taken from each hop yard to assess the balance of nutrients to ensure high quality and the best yields (image). 
• The twining process begins in early April with crews using tractor-drawn elevated platforms to tie the twine to overhead trellis wires and secure the lower end of the twine into the ground using metal clips (image).
• Training is the practice of wrapping hop shoots in a clockwise direction around the twine to begin their journey to the top of the trellis (image).
•  During the summer months, regular crop maintenance occurs including weed control, pest and disease management, and irrigation. (image).
• Harvest begins in August and progresses through early October.  Each variety reaches peak maturity at a different time. (image)

HOPS IN THE HOME GARDEN

The Plant

The hop plant Humulus lupulus L. is an herbaceous perennial, producing annual vines from an overwintering rootstock. In the spring and early summer, vines grow rapidly, winding around their support in a clockwise direction and clinging with strong, hooked hairs. They reach their ultimate height of 15-25 feet by the end of June when, in response to shortening daylength, vines stop growing vertically and produce sidearms which bear the flowers. The hop is dioecious, having separate male and female plants. Only the females produce the cone-shaped "hops" used in brewing. The male plant serves only as a pollenizer, but is not essential for the female plants to produce hop cones. Hops are heterogeneous and new plants coming from seed could be either male or female. The rootstock is an underground structure consisting of both rhizomes (with buds) and true roots (without buds) which may penetrate the soil to a depth of 15 feet or more. During the first year little growth and few flowers are produced because the plant is establishing its root system. A normal crop of hops should be expected the second year.

Climate

The hop plant produces best under specific climatic and soil conditions. A minimum of 120 frost free days are needed for flowering. Direct sunlight and long daylength (15 hours or more) is also needed. As a consequence of daylength and season length, hop production is limited to latitudes between 35 and 55 degrees. The hop plant requires ample moisture in the spring followed by warm summer weather. In dry climates the hop plant will produce best if supplemental irrigation is provided.

Soil and Plant Nutrition

A deep well drained, sandy loam soil is best. Soils with a pH of 6 to 7.5 is ideal for hop production. Poorly drained, strongly alkaline or saline soils should be avoided. Fertilizers rich in potassium, phosphate, and nitrogen should be applied each spring. Nitrogen is required at a rate of approximately 150 lbs per acre (3 lbs N/1000 ft2). The nitrogen may be applied in split applications 2 or 3 times between March and mid-July. If manure or compost is applied around the hop plant, fertilizer applications may be reduced accordingly.

Planting

The soil should be tilled to create a weed free area. A strong support system is needed for the plant to climb on. Look for space along fences, garage, or property lines. Plant in early spring once the threat of frost is gone but no later than May. The soil should be worked into a fine, mellow condition prior to planting. In cold climates you can plant rhizomes in pots and transplant in June. If planting is delayed, keep rhizomes refrigerated in a plastic bag to prevent them from drying. Plant two rhizomes per hill with the buds pointed up and cover with 1 inch of loose soil. Hills should be spaced at least 3 feet apart if the hills are of the same variety and 5 feet apart if they are different. The first year the hop plant requires frequent light waterings.

A hop quarantine in the state of Oregon prohibits hop plants and all plant parts, except kiln dried cones, from entry into the state directly, indirectly, diverted or reconsigned. There is an exception for the states of Washington and Idaho meeting specific conditions. This quarantine was established to prevent the introduction of diseases.

Pruning

When the young vines are about 1 foot long, two to six vigorous vines are selected for each hill and the rest are removed. One to three vines are trained clockwise on a string which has been staked to the hill. Hops mainly grow vertically, but lateral sidearms extend from the main vine and produce flowers. The main concern is to support the vines and prevent the sidearms from tangling. Most cones are produced on the upper part of the plant.

In July, the lowest four feet of foliage and lateral branches can be removed to aid in air circulation and reduce disease development. The removal of lower leaves (stripping) must be done carefully to avoid breaking or kinking the main stem. In August allow additional bottom growth to remain to promote hardiness of the crown and plant vigor for next year.

At the end of the season you can bury healthy bottom vines for propagating new plants the next spring. Simply bury the vines in a shallow trench and mark their location. In spring dig them up and cut them into pieces about 4 inches long. Make sure each new cutting has an eye or bud.

Diseases

• Downy Mildew - This disease is caused by the fungus Pseudoperonospora humuli. The fungus infects only the hop plant and will not affect other garden plants. The disease first appears in the spring as infected shoots (spikes) emerge from the overwintering rootstock. The number of infected shoots may vary from none to all in any given hill. Infected shoots are stunted, brittle, and lighter in color than healthy shoots. The leaves are often deformed and curled. Infected shoots are unable to climb. Gray or black masses of fungal spores are often present on the underside of infected leaves. Spores are dispersed by wind and rain. The disease is favored by warm (65-70°F) wet weather and the fungus requires free water on leaf and shoot surfaces for infection. Spiked shoots should be removed promptly and buried. Flowers often become infected when blooming occurs during wet weather. Young cones that are infected stop growing and turn brown. When older cones are attacked, part or all of the petals turn brown and cones fail to develop properly.

• Verticillium Wilt - This disease is uncommon in the Pacific Northwest. Symptoms include yellow veining of the leaves and wilting of leaves and vines. Early symptoms may include wilting on only one side of a leaf. A brown discoloration inside the vine may be observed by cutting diagonally into the vine. Depending on the hop variety and the strain of the fungus, disease can vary from year to year. A plant showing symptoms this year may seem entirely healthy the next year. There are no effective control measures. The fungus can persist in the soil for several years. If this disease recurs regularly, remove the infected plant and replace with a new one in a different location.

• Abiotic Wilt - Hop plants are extremely sensitive to soil residues of the pesticides heptachlor and chlordane. Chlordane was widely used in home gardens in the l960's but both were banned in 1972. Symptoms of heptachlor and chlordane poisoning may be similar to those of Verticillium wilt but there are some important differences. The lower part of the affected vine will have a rough, scaly appearance with deep cracks which may ooze sap. Vines are brittle and may easily snap when bent. In cross-section, the central sap of the vine may have a darkened, water-soaked appearance instead of a light color. Plants will likely exhibit a slow decline over a period of 2-3 years. There is no known cure. The hop varieties Cluster and Chinook seem to be somewhat more tolerant than other varieties.

• Viral Disease - Symptoms of virus infection vary with environmental conditions. The virus may cause leaf and vine tip distortions, tip die back, yellow spotting of the leaves, stunted growth, failure to climb on the trellis and flower blasting. There is no cure and severely affected plants should be removed and destroyed. Over the years many of the most severe viruses have been eradicated from commercial production. Rootstock purchased from a reliable propagator is unlikely to have severe virus problems.

Pests

Hop aphids and spider mites are the most common hop pests. Other less serious insect pests include wire-worms, leaf rollers, armyworms, hop looper, root weevils, omnivorous leaftiers, western spotted cucumber beetles, corn earworms, and several species of cutworm. These usually are not present in damaging numbers.

• Hop aphid, Phorodon humuli - The hop aphid is a small (2mm) soft bodied, pale green pest. The hop aphid overwinters on Prunus species (ie. ornamental plum trees) and in the spring return to the hop plant. Hop aphid infestations develop more rapidly during cool weather. The hop aphid does damage by sucking plant juices. Aphids should be controlled before or during flowering to keep them from entering the young cones. Once the aphids have entered the cones, they will secrete a honeydew and cause a sooty mold in the cones.

• Spider Mites, Tetranychus urticae - The adults are very small, have eight legs. They are pale green, yellowish to reddish in color, often with a dark spot on each side of their body. A hand lens is needed to see the pearly white spherical shaped eggs. The spider mite feeds by puncturing the lower leaf surfaces and withdrawing plant sap. Each puncture produces a small light colored spot. Eventually the leaves become bronzed, shrivel and die. White webs may also appear if infestation is severe. The spider mite will also feed on the petals of the cones causing them to turn brown, a condition growers call "red hops". Spider mites are a problem during prolonged periods of warm, dry weather. Mite predators include the western predator mite and the small black lady beetle. Regular washing of the plant's leaves with your garden hose may prevent an outbreak.

• Cutworms - Cutworms over-winter as larvae or pupae in the soil. The adult moths emerge in late spring and lay eggs. The larvae that emerge from the eggs feed on plant stems at night. Cutworms can generally be found just beneath the soil surface during the day.

• Prionus beetles, Prionus spp - Adult beetles may be 1.5 to 3.5 inches long and .75 inches wide. Their long sweeping antennae may appear sawlike. Larvae are white, fleshy grubs, without legs. The head is brown with forward-protruding, very strong, jaws or mandibles. Larvae may be 1.5 to 3 inches in length. They live in the soil and feed on roots.

Where to get them...

Hops are normally propagated vegetatively from rhizome cuttings (rootstock). The Spring is the best time for planting hops. The following is a list of Oregon nurseries who sell hop roots. 

As a reminder the state of Oregon is under a hop quarantine that prevents entry of hop roots from anywhere outside of the state.

Freshops
Dave Wills
36180 Kings Valley Highay
Philomath, Oregon 97370
Phone: 541-929-2736
sales@freshops.com
www.freshops.com

Nichols Garden Nursery
1190 North Pacific Highway
Albany, Oregon 97321-4580
Phone: 800-422-3985
FAX: 800-231-5306
www.nicholsgardennursery.com

Willamette Valley Hops
18704 French Prarie Rd NE 
St. Paul, OR 97137 
Phone (503) 633-4677
Toll Free: 1-855-815-HOPS
hops@wvhops.us
http://www.wvhops.us

Weeks Berry Nursery
John Weeks
6494 Windsor Island Road N
Keizer, Oregon 97303
Phone: 503-393-8112
FAX: 503-393-2241
www.weeksberry.com

The Thyme Garden
20546 Alsea Hwy
Alsea, OR 97324
herbs@thymegarden.com
http://www.thymegarden.com

Lone Oak Hop Farm
Steve: (503) 851-4695
Brandon: (503) 932-3887
loneoakhopfarms@live.com
www.loneoakhop.com 

Crosby Hop Farm
Blake Crosby
8648 Crosby Rd. NE
Woodburn, Oregon 97071
Phone: 503-982-5166
FAX: 503-981-2141
hops@crosbyhops.com
www.crosbyhops.com