Guest post from Brenda Lynn who is a freelance writer, Master Gardener and beekeeper living in northern Virginia. Read more in the March/April 2017 issue of Horticulture
As the craft beer and locally grown food movements sweep the landscape, gardeners and home brewers alike are growing their own hops, generating ever more flavors and stretching the boundaries of back-yard gardens. The common hop (Humulus lupulus) has more to offer than meets the taste buds, though. Cultivars are grown for ornamental color, privacy screens, livestock feed and even medicinal purposes.
Hops are ripe in late summer. Mature cones will feel papery and may leave pleasantly aromatic golden lupin stuck to your fingers.
HISTORY OF HOPS Malt beverages are as old as civilization, yet the alliance between hops and beer is fairly recent. The ancient Romans gathered wild hops for salad greens, and hops-filled pillows were once a common folk remedy for insomnia. French Benedictine abbots were the first to recognize hops’ antimicrobial properties. In 822 AD, they recorded its use in brewing, and the formula for modern-day beer began to take shape.
Today, Germany is the world’s largest hops producer, but German brews didn’t include hops until around 1079. Ale was traditionally flavored with a combination of bitter herbs and berries known as gruit. Hops’ introduction sparked uproar, and the ingredients of malt beverages were soon embroiled in taxes, religion and politics. In 1516, Germany passed the infamous Reinheitsgebot (German beer purity law), which mandated that beer include only water, barley and hops. Demand for hops grew, and it became a major agricultural crop across Europe.
English and Dutch pioneers brought hops to the United States in the 1600s. Finding native hops in the new world, they crossbred plants to create climate-specific cultivars. American-grown hops gained popularity abroad, particularly when war devastated European agriculture. By the mid-20th century, mass-marketed (albeit bland) beer dominated the market. The 1980s ushered in a new era of culinary acuity, including renewed interest in hops’ multifaceted flavors. Microbreweries now abound from coast to coast, and consumers clamor for local ingredients. The time is nigh for growing hops.
Hops require a strong support and early training to keep their quick-growing stems, or bines, from becoming a wild tangle; they can be assigned to individual posts to help avoid tangling.
GROWING REQUIREMENTS Hops are hardy perennials that generally need 120 frost-free days and full days of direct summer sun. They thrive in USDA Hardiness Zones 3 through 8. Internationally, commercial hops production falls between 35 and 55 degrees of latitude, but local demand is disrupting traditional notions about what grows where. Innovative growers are manipulating microclimates and introducing ever more disease- and weather-resistant cultivars.
In cooler climates, plant hops along a south- or west-facing wall to take advantage of its radiating heat. In hot, dry climates, select a location that receives partial afternoon shade. Sandy loam with a soil pH of 6.0 to 7.0 is ideal, but hops grow in a range of soils. Good drainage is key. After the danger of frost is passed, plant rhizomes 2 inches below the soil surface with buds facing upward, or space cuttings 24 to 36 inches apart. Apply a balanced fertilizer (16-16-16) to encourage initial growth.
Once days are consistently warm, shoots emerge and rapidly climb skyward. Early pruning will prevent your yard from becoming a hops jungle. Select three strong bines and train them in a clockwise direction around a post or trellised twine. Snip weaker shoots at ground level. Once the bines are trained, remove foliage growing up to one foot from the ground to prevent disease and allow air circulation.
During the first year, focus on root development, rather than harvest, to ensure healthy revival the following spring. A five-foot support structure will encourage dense foliage, but fewer hops. The energy saved by foregoing fruit allows the root system to store carbohydrates for future growth. (Hops die back to the crown at fall’s first frost, but the underground root system remains hardy.) The following year, provide a 15-foot support, and look forward to a bountiful harvest.
Newly established plants benefit from frequent watering. Drip irrigation helps ensure consistent moisture, and mulching with compost or straw will conserve water. Excess moisture on foliage contributes to mildew, so its best to avoid overhead sprinkling. In wetter climates, such as the Pacific Northwest, disease-resistant cultivars ‘Cascade’ and ‘Crystal’ are more successful.
Spider mites, Japanese beetles and aphids can attack foliage in summer, particularly in warmer climates. Check frequently for pests, and use miticides or insecticidal soap to cut down on insect damage. ‘Zeus,’ ‘Cascade’ and ‘Nugget’ have shown success in the humid Mid-Atlantic.
HARVESTING HOPS Hops usually mature in late summer, depending on the cultivar and climate. Determine if hops are ready for harvest by picking a few from the upper canopy. Mature cones will feel dry and papery. Golden lupulin may stick to your fingers, leaving a pleasant aroma. If hops are too high to reach, cut bines down to three feet and lay them on the ground to pick. The tiny hairs may irritate skin, so wear gloves.
Back-yard gardeners have the good fortune to choose how they wish to use their hops. Traditionally, brewers preferred dried hops, which have a longer shelf life. In the 1990s, microbreweries with access to locally grown hops experimented with freshly picked cones. These so-called wet hops impart a sweeter, vegetal flavor, but they must be used within 24 hours of harvest.
To dry hops, lay them on large screens in a well-ventilated location for several days, or dry them in a 125˚F oven for two hours. Once they’re dry, store cones in airtight containers or freeze them. Regardless of their intended use, hops remain firmly rooted in our culture. Growing some will undoubtedly spice up neighborhood conversation.