The Pacific Northwest is an optimal location for hop production due to its unique terroir and irrigation resources. Specifically, the Willamette Valley's rich soil, mild climate, and abundant rainfall provide ideal conditions for commercial hop production. The moderate temperatures experienced during the growing season are particularly favorable for growing high quality aroma-type hops. Several alpha-type varieties also favor the Oregon climate and consistently yield higher than average harvests.
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 IN THE HOME GARDEN
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.
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.
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.
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.
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.
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.
Nichols Garden Nursery
1190 North Pacific Highway
Albany, Oregon 97321-4580
Weeks Berry Nursery
6494 Windsor Island Road N
Keizer, Oregon 97303