Hops, along with water, malted barley and yeast, are the four main ingredients in most beers. Hops add bitterness to beer that helps balance the sweetness. They also add a floral aroma to heavily hopped beers. Not only can you brew beer with hops, these plants look great as ornamentals and can serve a very practical purpose for home beer brewers. Best of all, growing hops at home does not require a “green thumb.”
Hops are a product of the common hop plant (Humulus lupulus). The hop plant is a vining perennial that grows up to 30 feet vertically each year before dying back in the fall. Over the winter, the plant’s rhizome (an underground stem) awaits the arrival of spring, when it sends up young shoots. Grown commercially, these shoots latch onto the ropes of a trellis and grow upwards. In the wild, the plants generally climb trees. The vines of the hop plant do not send out tendrils, like many vining plants do. Instead they rely on tiny “hairs” to stick to their trellis wire or other support. This type of vining plant is called a bine, and the vines of this type of plant are also called bines.
Near the end of the growing season, female plants flower. (In a commercial hop yard, no male plants are grown, as their pollen lowers the quality of the hops.) This flower – a tiny, green spiky structure that looks nothing like your typical petalled, ornamental flower – develops into a cone. It is this cone that is used for bittering beer.
Hops are hardy plants that grow well under most reasonable circumstances. The hardest part of growing hops is installing the trellis – something you only need to do once. For the home beer brewing enthusiast, hops can be used in beer production. For non-brewers, hops are simply an attractive ornamental or a supplement to your chickens’ diet. Lastly, in light of the home brewing and craft beer craze, and the shortage of hops it’s created at times, market homegrown hops to beer brewers of all sizes. That’s a niche that will lead to supplemental income.
Hop growing regions
Commercially, most hops are grown between the 35th and 55th parallels, but hobbyists can grow them well outside this zone. I grew hops for several years in central Texas. In the United States, two of the largest hop growing regions are Washington state’s Yakima Valley and Oregon’s Willamette Valley. Idaho is the third largest producer of hops in the U.S. Historically, New York was home to many hop yards. With interest increasing in both craft beers and locally grown ingredients, commercial hop growing is once again happening in New York.
Trellising your hops
Before you start planting, the first thing you should do is install your trellis. The simplest trellis can be made by screwing some eye hooks into the roof line of your house and dropping lines of heavy twine from the hooks. Alternatively, home hop growers erect tall poles and grow several plants around the base of the pole. Your trellis should be able to hold a mature hop plant on a windy day. Extremely flimsy trellises will get knocked over by the wind.
You will want to drop three to four trellis lines for each hop plant. Some commercial farms use a heavy twine made from coconut husks, and use telephone poles as the support for their trellises. Steel cables stretch from the top of one pole to the other, and the hop twine hangs from the cable. Ideally, your hop plants – collectively called a hop yard – should get sun all day long.
Selecting your hop rhizomes
Hop rhizomes are available for sale during early spring each year. Many homebrew shops will sell rhizomes, and numerous vendors can be found online.
There are many varieties of hops available, and for first-time North American growers, many of the popular American varieties are hardy and will grow at almost any latitude. Cascade is a variety that is prized for its brewing characteristics, and it’s easy to grow. The same goes for Centennial, Columbus and Nugget. European aroma varieties – such as Hallertau, Tettnang and Saaz – are more difficult to grow, and their brewing properties differ when grown in the U.S.
When you receive your hop rhizomes, wrap them in damp newspaper (if they aren’t already), and store them in your refrigerator until it is time to plant. Don’t store them sealed in a plastic bag – although they may be shipped that way – as the rhizome is alive and requires oxygen. Any time after the soil becomes workable is fine for planting.
Planting the hops
Hops are planted by burying sections of their rhizomes. When you are ready to plant, dig a basketball-sized hole to receive the rhizome. The rhizome will likely be roughly the length and thickness of a pencil. Digging a large hole will loosen the soil so the roots that emerge can establish themselves easily. If your soil is similar to ordinary garden soil, mix it 1:1 with compost. This is richer soil than is necessary, but it will help the plant establish itself the first year.
Avoid planting hops in areas where water collects, as the rhizome can easily rot, killing the plant. Once you’ve dug the hole and the soil is prepared, refill the hole until the soil is level with the ground. Place the rhizome on top of the soil and bury it roughly 2 inches deep. Some sources recommend planting the rhizome vertically, which also works. Keep the soil evenly watered, though not drenched, until the shoots emerge. You can also grow hops in containers, although they will need to be at least the size of a wine barrel to be successful.
Every year, the rhizome will send out underground roots and aboveground shoots. In three or four seasons, it will grow from the pencil-sized “stick” you planted to a tangled mass of finger-thick stems about the size of a basketball. This is called a crown. You can harvest new rhizomes to plant from any crown. This is usually done in the early spring before the rhizome has sprouted. You can also transplant entire crowns or partial crowns. The larger the mass of rhizome you plant, the quicker the plants will establish themselves as the rhizome stores nutrients.
The first year
In the first growing season, you should train every shoot to your trellis lines, even if you have to train more than one shoot to a line. Hop production is very low the first year, and what you really want to do is just let the plant get established.
To train a shoot to a trellis wire, loosely wrap the wire around the shoot so that the hop bine is growing clockwise (when viewed from the top) around the wire. If you get it spiraling the wrong way, the bine will frequently fix the problem itself. Let the plant produce as much aboveground foliage as it wants (unless it gets unsightly), then cut down and compost the bine when it dies back in fall.
At the peak of growing season, when the bines are halfway or more up the trellis wire, growth is very fast. The bine can add almost 6 inches in length over 24 hours. Keep the plants evenly watered throughout the growing season to let them grow to their full potential.
Hops produce a lot of foliage each season, and they can take a lot out of the soil. You can side dress each hop plant with compost early in each growing season. If that isn’t enough, add liquid fertilizer as needed later. If the hop leaves begin to turn yellow-green or yellow, a little nitrogen will green them back up. Hop plants grow vigorously enough that there is no need to give them excess fertilizer. As long as the leaves are healthy and green, and the plant is growing steadily, it has enough nutrients.
Diseases and pests
Hops are susceptible to one type of downy mildew and a hop-specific powdery mildew. Ensuring that there is good airflow between bines will do a lot to prevent this, as will not intentionally applying water to the leaves. Otherwise, check which fungicides are approved for use in your area.
In hop growing regions, the hop aphid (Phorodon humuli) is a frequent pest. However, it is almost unheard of outside regions with commercial hop production. Some general insect pests, such as Japanese beetles (Popillia japonica), can also infest hop plants. Remember that if you are going to use the hops, you will need to check any pesticide you use carefully. If you only have a small number of plants, physically picking off insects in the morning when it’s cool and they’re moving slower can be effective if you are persistent.
Alpha acids of essential oils
The compounds in hops that make them bitter are alpha acids. The three most common alpha acids are humulone, cohumulone and adhumulone. Modern varieties of bittering hops have been bred to have high levels of alpha acids. The levels of alpha acids found in commercial hops – which ranges from around 3 percent in some European aroma hops to almost 20 percent in some of the newer high-alpha varieties – is measured and reported so that brewers can adjust their recipes to get a constant level of bitterness in their brews. The level of cohumulone is also reported (as a fraction of the total alpha acids) because low cohumulone hops are frequently described as less harsh than high cohumulone varieties.
As a home grower, you will not know the level of alpha acids in your hops unless you send them out for evaluation. As such, you will need to rely on the average level of alpha acids in the varieties you grow, or perhaps on the result of a test brew, to estimate your alpha acid levels. Some home brewers will only use homegrown hops as late-addition hops (for which the alpha level is less important) or dry hops.
The floral characteristics of hops come from the oils of the plant. As with alpha acids, the total levels of oils are reported for commercially grown hops. Likewise, four common oils – humulene, myrcene, farnesene and caryophyllene – are frequently reported separately. Humulene is often referred to as having the most pleasant aroma, whereas myrcene is often judged to have a harsh grassy character. However, when using homegrown hops, you’ll just have to trust your nose to judge the level and quality of the oils.
Both the alpha acids and the oils are produced in the plant’s lupulin glands. If you pull apart a hop cone, you will see numerous tiny yellow specks. These are the lupulin glands, and almost every reason for which hops are grown are found here. In other words, when you think about it, you grow a 30-foot hop plant in order to harvest a bit of yellow “dust” from inside the cones. If you crush a cone between your fingers, or rub several cones together in your hands, the lupulin glands will rupture and you can smell the wonderful hop aroma.
It usually takes at least three years for hops to start producing up to their full potential. From the second growing season onward, the steps you take are the same. In spring, the shoots will emerge. Once they are long enough, train the fastest growing three to four to the trellis wire, and cut all others as they emerge. One variation of this is to let the first set of shoots grow until they are about a foot tall, then cut them all back and train the next three to four best shoots. The rest of the growing season, all you need to do is keep the plants watered and clip off new shoots as they emerge.
You should yield enough hops to harvest in your second year. The amount of bitterness in these hops will likely be less than what the variety is capable of producing, but this will increase to normal levels in the third year. Hops are a light green color and are ready to harvest when the tips of the bracts – the “scales” covering the hop cone – turn brown. To harvest on a home scale, cut the bine down and pick all the cones. You’ll want to wear work gloves as you do this as hop bines are abrasive on your skin.
You can use freshly harvested hops for brewing if you’re making a so-called “wet-hopped” beer, but most hops are typically dried and stored before use. The simplest way to dry hops is to spread them out on a screen and let them sit until they feel papery and break apart easily when rubbed between your hands. You can also use a food dehydrator. Commercially produced hops are dried in a heated chamber called an oast.
Growing hops is pretty straightforward. The hardest thing is building your trellis. Hops can thrive in any moderately rich, well-drained soil, and most often require little by way of tending after the shoots have been trained. If you keep them watered, they’ll keep growing and growing. When full-sized, they look spectacular, and if you’re a brewer or look to market hops to home brewers, they might become your new favorite plant in the garden.
Chris Colby is an avid gardener who lives in Bastrop, Texas, with his wife and their cats. His academic background is in biology – a Ph.D. from Boston University – but his main interest is in brewing beer.