How to Grow Hops

One plant, twenty years, and about six metres of string.

Hops are a herbaceous perennial climber. The top dies back to the crown every winter and comes away again in spring, and it does that for twenty years or more from a single planting. What it demands in return is height, and that is the part people underestimate.

Height first, everything else second

A hop bine will run five to seven metres in a season, and it wants to go up rather than along. Give it less and you get leaves and very few cones, because the flowers form on side arms that only develop once the bine has run its length.

The usual home setup is a length of coir or twine from a ground anchor up to a bracket on a roofline, a tall fence post, or a wire strung between two posts.
Coir rather than nylon. The bine grips rough natural twine and slides on smooth synthetic.
Full sun and shelter. They will take wind but a whole bine torn down in a summer storm costs you the season.
Do not plant against a wall that gets no air. Hops mildew readily and want airflow on both sides.

If you genuinely have no height, grow them anyway on a horizontal run and treat the first crop as a bonus. But the vertical version is the one that works.

When to plant

Plant dormant rhizomes in late winter through spring, August to November. New Zealand grows hops commercially around Nelson and Motueka for good reason: the combination of cold winters and long summer days suits them, and most of the country can manage a backyard crop.

Planting the rhizome

Hops are sold as dormant rhizomes, a knobbly piece of root with buds on it. Seed is not worth bothering with, because half of what you raise will be male and males make no cones.

Dig in plenty of compost. Hops are hungry and the crown stays put for decades, so this is the one chance to improve that ground properly.
Lay the rhizome horizontally, buds facing up, about 5 cm or two inches deep.
One plant per string, and a metre between plants if you are growing more than one variety. They tangle.
Label it. Two varieties look identical in leaf and you will not be able to tell them apart at harvest.
Mulch well but keep the mulch off the crown itself.

The first year, and why it disappoints

A first-year plant puts its effort into the root system and gives you a handful of cones at best. This is normal and it is not a sign you have done anything wrong. The second year gives a real crop and the third is the plant at full strength.

Knowing that in advance is most of the battle, because a great many first-year hop plants get dug out in disappointment about a month before they would have become useful.

Training and looking after them

Choose three or four strong bines once the shoots are about 30 cm long and cut the rest off at ground level. Left alone you get a dozen weak bines and no cones.
Wind them clockwise around the string, which is the direction they naturally take. Wound the other way they unwind themselves overnight.
Strip the bottom metre of leaves and side shoots once the bine is established. It improves airflow and cuts mildew and aphid problems considerably.
Water steadily through the growing season. Hops are thirsty and drought-stressed plants make small cones.
Feed in spring with compost or a balanced feed, then leave them to it.

Knowing when to pick

Cones ripen over a couple of weeks in late summer and the window is not enormous. Judge by feel rather than by date:

Papery, not soft. A ripe cone feels dry and springs back when you squeeze it. An unripe one feels damp and stays squashed.
Yellow lupulin. Tear a cone open. The powder at the base of the petals should be deep yellow and sticky, and it should smell strongly of the variety.
A little browning at the tips is fine. Cones going brown all over have gone too far and the aroma is already dropping.

Pick into a basket rather than a sealed bag, and expect to go over the plant twice as different cones come ready.

Drying, which decides whether they were worth growing

Fresh cones are about 80 percent water and will compost themselves inside two days. Drying is not optional and it is where most home crops are lost.

Spread the cones one layer deep on a mesh rack somewhere warm, dark and airy. A fan helps enormously.
Keep it under about 60 degrees Celsius, or 140 Fahrenheit. Hotter than that and you drive off the aromatic oils you grew them for.
They are ready when the central stem snaps rather than bends, usually one to three days.
Vacuum seal or press the air out, and freeze. Stored that way they hold their character for a year. Left in a paper bag in a cupboard they are stale by Christmas.

What goes wrong

Leaves but no cones. Nearly always not enough height, or too many bines left on.
Powdery mildew. Poor airflow. Strip the lower metre and thin the bines.
Aphids and spider mite. Both love a dry stressed plant. Water properly and hose the undersides.
Nothing in year one. Not a problem. Wait.

See also: Hops in the Plant Library for planting months tuned to your region, and Trellis and supports for building something that will hold a full-grown bine.