Growing hops at home: planting, maintenance & hop varieties
Hops are mostly associated with beer and its production. Many gardeners do not realise, that hops can be grown as a decorative plant in the garden. We have summarised everything worth knowing about this versatile perennial for you below.
The common hop (Humulus lupulus) belongs to the hemp family (Cannabaceae). Without a doubt, most people have one clear association when it comes to hops: beer. Although the vast majority of hops grown in the world is used for brewing beer, that’s not all there is to this plant. This perennial, which originally comes from Central Europe, was not chosen as the medicinal plant of the year in 2007 just because it’s used for beer brewing. The common hop has many other valuable qualities. In the following, we will explain why beer and hops work so well together and show you how to grow this medicinal plant in the comfort of your own garden.
Growing hops in the garden
Planting hops: the right location
The common hop loves the sun. When cultivating hops in your own garden, these plants should not be denied sunlight – a location on the southern side of the house is definitely the best place for hops to grow. This is also the reason why most of the hops produced commercially in Europe is grown in the sunnier areas. For example, the Hallertau region in Germany is particularly famous for growing hops.
Not only the wild form of the common hop, which is often found in very humid areas, enjoys a nitrogen-rich supply. To grow hops at home, a well-fertilised substrate should be used, especially when cultivating hops in pots. If you intend to plant hops out in the garden, keep in mind that these plants form rhizomes. Rhizomes are subterranean shoots from which new, vigorous plants emerge to the surface every year. Therefore, once you are done with hop cultivation, every single rhizome of the plant has to be dug up and removed from the ground. Otherwise, new shoots will continue to sprout from them.
Reproducing hops: cuttings or seeds?
The most common as well as the most widely recommended method of hop reproduction is to propagate cuttings. There is a significant reason for this: only unfertilised, female inflorescences form the coveted hop cones. The structure of male panicle flowers is fundamentally different from that of the spike-shaped female flowers.
On the one hand, fertilisation of the female flowers is disadvantageous for processing in the brewery but, on the other hand, not as much as beer wort can be produced from the same mass of hop crop as from the non-fertilised flowers. If you hold a bag of hop seed in your hand, you will not be able to tell for sure whether the seeds are female or male. Later on, in mixed seed hop cultures, the female flowers can be fertilised unintentionally. To avoid this faux pas, the hop varieties are best propagated exclusively by means of cuttings. If you want to plant hops in your own garden, it is therefore advisable to buy young plants which have already been started.
Growing hops: watering and fertilising
Hops require a lot of nutrients and water to grow well. This comes as no surprise: hop vines can grow up to 10 cm a day! The soil, on which the hop plants grow, must always be kept moist. However, waterlogging has to be avoided at all costs as it would lead to an insufficient oxygen supply to the roots and consequently to the deadly root rot.
Because hop plants need a lot of nutrients, additional fertilisation is essential, especially in pot cultivation. Just like with watering, fertilising must be adapted to the rapid growth of the hops. This means that with increasing size the intervals between fertilising should be shortened. In other words, you should fertilise more often as the plants grow bigger. Thus, in early summer, hop plants should be supplied with extra nutrients up to once a week. It is important to note, though, that fertilising should be stopped completely once hops start flowering. However, even during bloom, watering remains a full-time job: especially when cultivating in pots, watering must be done daily on sunny, warm days to ensure optimum supply to the plant. We also advise using a pot that is not too small for this thirsty perennial.
Growing hops: pruning and stringing
Hops can grow to an impressive height of 4 to 8 metres, depending on the variety. Without proper support, the thin shoots of hops are not be able to grow upwards at all. Therefore, three to four climbing vines per rhizome should be tied up to a climbing aid made of wires. This should be done as soon as the individual shoots become so long that they can no longer bear their own weight. We would like to point out that hops are right winding plants, which means that in order to climb up the supporting aid, they have to be tied up clockwise. All other shoots sprouting from the same rhizome are cut out. This increases the yield of hop cones.
Pruning for winter is not necessary. All above-ground parts of this perennial plant will die off on their own. The nutrients from the vines are relocated to the rest of the plant underground. This gives the rhizome enough power to push the fresh shoots back to the surface next spring. Incidentally, the rhizome of hop plants native to regions with temperate climates are not susceptible to frost damage. Even prolonged permafrost cannot harm the robust hops.
Like most plants, hops are not completely immune to pests and diseases. Hops can be infested by aphids. What many do not realise, is that these little pests can be combatted with ordinary household items as opposed to commercial chemical products. For example, pouring some nettle liquid manure over the affected plants can help against aphids. Alternatively, you can also rinse off the plants with a mixture of some dishwashing liquid and water. You can learn about other household remedies against aphids in this article.
Next, many hop varieties are also susceptible to powdery mildew. The best alternative to chemical plant protection is to choose a less susceptible or even a mildew-resistant variety.
Hop varieties: which are the best?
There is a great diversity to varieties of hops – hundreds of different types of hops are available on the market, which means that there is something for everybody to enjoy, regardless if you want to brew beer or use hops for a different purpose. Hop varieties range significantly when it comes to their taste. While some taste sweeter and fruitier, other are known to have notes of menthol and are a little spicier.
Hop varieties can be divided into two sub-groups based on their alpha-acid content. On the one hand, the so-called bitter hop varieties have an alpha acid content of over 10 %. On the other, all varieties below 10 % are referred to as aroma hops. The low alpha acid content reduces the bitterness of the hops. However, the aroma hops contain a higher concentration of essential oils. Depending on the composition of the aroma, this can contribute to the hops’ own special flavour. Here are some of the best hop varieties you might want to grow in your garden:
Dark hop varieties:
- ‘Nugget’: strong growth and high yield; very susceptible to disease; low demands on the soil
- ‘Target’: low demands on the soil; very beautiful, closed umbels; less susceptible to powdery mildew
- ‘Hallertauer Magnum’: high bitter constituents; strong growth; grows the largest umbels and leaves
- ‘Northern Brewer’: early ripening; less productive but contains a large amount of bitter substances
Aroma hop varieties:
- ‘Hersbrucker’: traditional variety; distinct spicy note; overall good aroma
- ‘Hallertauer mittelfrüh’: old variety; still popular in cultivation thanks to its aroma; large dark green leaves; aesthetic growth
- ‘Centenniel’: popular variety in the USA; aroma reminiscent of beetroot and berries mixed with woody notes
- ‘Citra’: aroma hop variety of high value; varied fruity aroma
- ‘Amarillo’: moderate aroma; sweet fruity yet spicy notes
For the aroma and bitter hop varieties used in commercial cultivation, another breeding objective is to develop of small but high-yielding varieties. This would greatly facilitate mechanical processing of the crop.
Other than aroma and dark hop varieties, there are also some one-of-a-kind hop varieties offered on the market that can enrich a hobby gardener’s bed. They are usually characterised by a marked lack of demands in terms of location.
Unique hop varieties:
- ‘Billbo’: extremely low in bitterness; very suitable for teas; not the best variety for beer brewing
- ‘Comet’: very decorative light green to yellow foliage; very large and conspicuous umbels
- ‘Gimmli’: dwarf; shoots reach a length of 4 m when tied up; well suited for cultivation in pots or containers; resistant to powdery mildew
Harvesting and storing hops
From the end of August to mid-September, the hop cones, that are so revered by beer lovers, can be harvested. When the cones are ready for harvesting, they shed the yellow powdery hop resin. Then, the elaborate manual selection process follows. In commercial cultivation, the hops vines are cut off as a whole just above the ground and removed from the climbing aid. On smaller farms, the unfertilised female inflorescences are then separated from the shoots with the help of a specialised machine.
In principle, the harvested hops are then dried to extend their shelf life. Either the umbels can be air-dried, or the process is accelerated in the oven. Here, moisture is removed from the umbels at up to 80 °C for one or two hours. When it comes to the air-drying method, it is important to choose a dark place so that the green colour of the umbels is preserved as much as possible. If the dried inflorescences are subsequently compressed into pellets, the storage volume can be significantly reduced and, if the cap is airtight, the storage life is expanded even further and without a loss of aroma.
Hops: use and benefits
Hops make beer what it is – which is why they are used almost exclusively in the art of beer brewing. About 17 kg of hop cones are needed to brew 1000 litres of beer. It is common to use the dried inflorescences of the female hop plants for brewing. However, the brew can also be prepared with freshly picked hops. This is how the so-called green hop beer is prepared. The hop resins provide the characteristic bitter taste of beer due to the bitter substances lupulin and humulone they contain. Thanks to their antibacterial effect, the bitter substances of the hops also act as a preservative, which is why beer can be kept long. This positive property of hops has been discovered by Saint Hildegard von Bingen as early as the 12th century.
Furthermore, female hop cones are also valued in the form of tea. The infusion is said to have a calming and sleep-promoting effect.
Hops can also be made use of on the stove – young, fresh shoots of about 15 cm in length can be cut during budding and cooked as hop asparagus. It is important, however, that the shoots are still tender and young; the ideal harvest time is therefore from about mid-March to early April. Preparing hop asparagus is not different from cooking its namesake, the classic asparagus. Interestingly, the hop asparagus brings an interesting resinous note to the plate.
If you are interested in cooking with hops as opposed to brewing beer, it is definitely worth cultivating this perennial in your own garden.