|Humulus lupulus subsp. var.||Common hop|
Common hop is a dioecious, perennial herbaceous climbing plant which sends up new shoots in early spring and dies back to the cold-hardy rhizome in autumn. It is native to the temperate Northern Hemisphere.
|Standard Cyclopedia of Horticulture|
Humulus lupulus, Linn. Common Hop. Perennial herb shoots often grow 25-30 ft. long in the season: rough-hairy: lvs. ovate or orbicular-ovate in general outline, deeply" 3-lobed (sometimes 5-7-lobed), or the upper ones not lobed, margins strongly and uniformly dentate, petioles long: staminate fls. in panicles 2-6 in. long: hops (mature pistillate catkins) oblong or ovoid, loose and papery, straw-yellow, often 2 in. or more long, glandular and odoriferous.—Native along rivers and in thickets in the northern states and Canada, and southward in the Alleghanies and Rockies; occurs as far south as Fla. and Ariz. Much cult, for "hops," used in brewing, and extensively run wild from cult, plants. The hop makes an excellent arbor or screen plant. Var. aureus has yellow foliage. The hop grows readily from cuttings of the shoots, which spring from the crown; also by seeds, but the latter do not reproduce the particular varieties or strains. As a field crop, the hop is not a horticultural subject, and is not discussed here. The Rocky Mt. form, common in Colo, and New Mex., has been separated as var. neo-mexicanus, Nels. & Ckll., and it is in the trade: it has more deeply divided lvs. and more sharply acuminate bracts than the ordinary hop; If .-segms. from broad- lanceolate to nearly linear, acuminate, with resin particles on the lower surface.
It is hardy to zone 5 and is not frost tender. It is in flower from July to August, and the seeds ripen from September to October. The flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required) and are pollinated by Wind. The plant is not self-fertile. It is noted for attracting wildlife.
The plant prefers light (sandy), medium (loamy) and heavy (clay) soils. The plant prefers acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It requires dry or moist soil and can tolerate drought.
Easily grown in a good garden soil in sun or semi-shade[1, 53]. Prefers a deep rich loam and a warm sheltered position. Plants can succeed in dry shade if plenty of humus is incorporated into the soil, once established they are also somewhat drought tolerant. Hops are reported to tolerate an annual precipitation of between 31 and 137cm, an annual temperature in the range of 5.6 to 21.3°C and a pH of 4.5 to 8.2. Plants are very hardy tolerating temperatures down to about -20°c when dormant. The young shoots in spring, however, can be damaged by any more than a mild frost. A climbing plant, supporting itself by twining around the branches of other plants. Hops are frequently cultivated, both commercially and on a domestic scale, in temperate zones for their seed heads which have many medicinal qualities and are also used as a flavouring and preservative in beer. There are many named varieties. They grow best between the latitudes of 35 - 51°N and 34 - 43°S, with mean summer temperatures of 16 - 18°C. Generally, for beer making, the unfertilized seed heads are preferred and so most male plants are weeded out. Hops are fairly deep rooted, but with a network of shallow feeding roots. These horizontal feeding roots spread out at depth of 20 - 30 cm in the soil and give rise to fibrous roots in upper layers of soil. The vertical roots develop downwards to a depth of about 150 cm with a spread of 183 - 244 cm and have no fibrous roots. The bruised leaves are refreshingly aromatic whilst the flowers cast a pleasing scent. A food plant for many caterpillars. Dioecious. Male and female plants must be grown if seed is required.
Seed - sow spring in a cold frame. Germination is fairly quick. Prick out the seedlings into individual pots as soon as they are large enough to handle and plant out in the summer or following spring. Division in spring as new growth begins. Very easy, you can plant the divisions straight out into their permanent positions if required[K]. Basal cuttings in March. Harvest the shoots when they are about 10 - 15cm long with plenty of underground stem. Pot them up into individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summer.
Pests and diseases
- Hop leaf aphid (Phorodon humuli)
- Red spider mite (Tetranychus urticae)
- Downy mildew (Pseudoperonospora humuli)
- Powdery mildew (Podosphaera macularis)
- List of hop diseases
There are five varieties of this species (Humulus lupulus):
- H. lupulus var. lupulus. – Europe, western Asia.
- H. lupulus var. cordifolius. – Eastern Asia.
- H. lupulus var. lupuloides (syn. H. americanus). – Eastern North America.
- H. lupulus var. neomexicanus. – Western North America.
- H. lupulus var. pubescens. – Midwest North America.
There are many cultivated varieties: see List of hop varieties
- Plants for a Future - creative commons text incorporated
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963