Most gardeners think of hops as an ingredient in beer rather than a vine they can cultivate in their own backyard. When you drink beer, the refreshing bitterness on your tongue and the complex aromas in your nose come from the brewer’s careful boiling or steeping of dried hop flowers. Hops also have a long history as an herbal and naturopathic cure. Hop-filled pillows are a common remedy for insomnia, and hop extracts and teas are suggested for calming anxiety and upset stomach. Hop oils are naturally antimicrobial, which is perhaps one of the reasons hops became the dominant flavoring component in beer: the stuff lasted longer and was a lot safer to drink.
However, you don’t have to be a home brewer or a naturopath to have a reason to grow these dramatic plants.
What are hops?
The hop plant, formally humulus lupulous, is a close relative of both cannabis and chamomile (think of them as the “sleepytime trio”). It is an herbaceous perennial with seasonal foliage growing up from an underground rhizome. It is hardy in USDA Zones 4–8, depending on variety. Dramatic growth is a noteworthy trait of the hop plant: sometimes it grows as much as four inches per day.
Botanically, hops are not a vine but rather a bine. The difference is that a vine climbs using small tendrils to grab support, whereas the entire stem of a bine spirals up and around whatever it can find. To support their climbing habit, hop stems are covered in tiny hooks and sticky, irritating resin. This is a good reason to avoid planting hops along high-use garden paths or patios.
As summer progresses, the hop plant produces its characteristic cones, called strobili. These only appear on female plants, which is why only female hops are cultivated. With colors ranging from pale yellow-green to dark green, the cones consist of tiny leaf bracts surrounding a visually insignificant flower. Yellow grains of the hop resins form on the bottom side of the individual bracts. When fall approaches, the cones puff up, the resin continues to develop, and the hop aroma grows more powerful. Pry one of the cones apart with your fingers and take a good sniff. If you intend to harvest, this is the time, as the cones are heavy with resin and starting to dry out.
Dry the individual cones thoroughly. A couple of days in a food dehydrator at the lowest temperature setting (or “fan only” if yours offers the option) will do the trick. Then bag in zipper-lock freezer bags, press as much air out as you can, and freeze. Frozen hops retain their bittering properties for 6–12 months (or more, albeit with declining effectiveness).
Hops in your garden
The hop plant’s stunningly fast growth is only part of the drama they can bring to a garden. They also have dramatic foliage, and these two traits make them an excellent summertime screening crop. They can be part of a passive energy conservation strategy: bines on a trellis provide summertime shade to south-facing windows and walls but let the light through again in winter, after the plants die back.
Don’t plant hops near pathways. As mentioned above, they are sticky and a bit prickly. Some folks are sensitive to the oils that a hop plant secretes. Wear gloves and a long-sleeved shirt when pruning or harvesting.
Plant hops in well-drained, well-mulched soil. They don’t like wet feet, so good drainage is crucial. You can hill up a low mound of sandy soil, as many commercial growers do. Soil pH should be between 5.5 and 8.0. Individual rhizomes should be spaced at 3 feet; further if you are growing different varieties and want to keep them separate. Plant them 4 inches deep with any visible growth or bud points facing up. After a few weeks cut back the weakest bines, leaving only two or three, to avoid crowding and overly dense growth, which promotes mildew.
Water frequently but lightly the first year, and do so early in the morning to avoid standing water overnight. An established plant shouldn’t need much supplemental water. Fertilize lightly using an organic fertilizer with nitrogen content about half that of potassium and phosphorus. Like lots of leafy plants, hops like a decent supply of boron. If you have a plant with suspiciously lax growth or faded leaf color, try sprinkling some Borax near its base.
A hop plant needs one thing above all else: something to climb. Something tall. Commercial brewers’ hop varieties can reach 20 feet or more, and it’s not unusual to see backyard plants climbing utility poles or gutter downspouts. That said, ornamental varieties (and some brewing varieties) are bred to stay within 8 to 12 feet.
With a little effort, hops can be trained to grow sideways. Coarse, heavy twine works best for this. It must be well secured and supported every 6 feet or so. Used this way, a hop is a great plant to enliven a fence.
Though hops aren’t listed as an invasive species, they can spread aggressively. The underground rhizome is always expanding: what was a lone bine one year might be three the next, and six the year after that. You can dig up an excessively vigorous plant during the dormant season and trim the rhizome. Luckily, the plant produces no seeds (since only females are grown), so you needn’t worry about volunteers showing up.
Hop pests and diseases
Newer hop varieties feature greater vigor and disease resistance than the landrace classics, but most hops are susceptible to a variety of ailments. In damp regions, mildew is most critical. Help prevent it by pruning off the bottom foot or two of leaves. A spray of copper fungicide can help, though well-planned plantings (plenty of space between plants and good drainage) are the best preventative. Black root rot, a result of overwatering, is another reason to ensure your hops don’t get too damp.
Hops are prone to a variety of viruses. Most of them (including apple mosaic virus and hop mosaic virus) affect productivity and alpha acid content (bittering potential). Select your plants from a reputable dealer: Hop rhizomes should be grown under controlled conditions from genetically pure stock.
Also watch out for aphids and spider mites, both of which can multiply quickly and severely damage a plant.
Hop Varieties to Try
Cascade is the classic, signature hop of the new generation of Northwest flavors. The Cascade aroma is of citrus and grapefruit. It has enough bittering alpha-acids to work as a dual purpose hop. It is fairly disease resistant and definitely a vigorous grower.
This is my favorite hop variety. In the garden, it is a strong grower and has good disease resistance. In a brew, it is another dual-purpose hop suitable for early bittering as well as late flavor and aroma additions. Chinook makes me think of a campsite in a pine forest after an overnight rain—spicy and piney with a little bit of smoky pungence.
Crystal is another US-bred variety with decent disease resistance and growing vigor. It is mild, herbal, spicy and a little bit floral. Traditionally an aroma and flavor hop, it can also be used for bittering if you’re not afraid to use a lot.
The most common ornamental hop these days is “Golden” (not to be confused with the Golding family of brewer’s hops). It could be thought of as semi-dwarf, offering somewhat less aggressive growth than the brewing varieties. The color, as you might guess, is on the pale and yellow side, particularly the cones.
This is a new dwarf ornamental hop bred for a more manageable habit and less aggressive climbing, even to the extent of needing a little assistance and training. It features golden foliage that slowly darkens over time.
Hops: A bit of legend, a bit of history
Hops have long been surrounded with an air of mystery. The phrase “hopping mad” is sometimes falsely attributed to the antics of seasonal workers hired to harvest the plant in the 1800. There’s no actual evidence to support this. If hop harvesters got a little crazy at the end of the day, it was probably from excess consumption of the finished product rather than exposure to the plant. Hops’ familial relationship with cannabis leads to rumors (perhaps borne of wishful thinking) that hops can induce hallucinations or lend something special to beer’s intoxicating power beyond what alcohol provides. Again, there’s no real evidence of this, and their closeness to chamomile does suggest that, if anything, a hop-laden beer is just going to make you a little more sleepy than a glass of wine or other drink.
Unbittered beer is almost undrinkably sweet and certainly not the refreshing beverage we expect today. For centuries, brewers used a variety of spices to bitter and flavor their brews. The use of hops originated in central Europe and soon spread to other regions. Hopped beers not only lasted longer but also evaded the taxes levied on brewing spices. But as quickly as brewers began to use hops, taxes followed. All through the 16th and 17th centuries, various royal edicts sought to manage hop growth, as much for economic reasons as anything else. Various organized efforts were made to stamp out the “wicked and pernicious weed,” ostensibly for moral reasons: but let’s be honest, no one likes to see a tax source dry up. In the end, the superior taste and longer storage life of hopped beers won out, though the two styles coexisted for quite some time, with the term “ale” referring to an unhopped brew and “beer” to a hopped one.