Maximum Yield Australia/New Zealand May/June 2019 | Page 70

“ HOPS ARE relatively easy to grow as
they are extremely vigorous and heavy
feeders that benefit from the controlled
nutrition of hydroponic systems.”
As with other larger hydroponic plants, hops are best grown
in a drip-irrigated system with at least two gallons of a free
draining growing substrate, such as perlite or coarser grade
coconut fibre, as they are intolerant of wet feet, particularly in
the early stages of growth. Nutrients should initially start with
a high-quality, general purpose vegetative formulation at an
EC of 1.8–2.2 with a high ratio of nitrogen to potassium. During
the later stages of growth, this can be switched to a flower-
ing/fruiting formation with higher potassium and phosphorus
levels, as well as gradually increasing the EC during the cone
production stage to maintain high levels of essential oils and
other compounds that constitute the quality of the flowers.
Hops are a warm-season crop; during the active growth phase
the crop requires light of similar intensity to tomato, cucum-
ber, and pepper crops. Good air flow is essential, particularly
around the lower levels of the plant where high humidity can
promote disease. While vigorously growing hop bines under
ideal growing conditions are relatively problem free, they can
be prone to mite infestations in warmer, drier conditions. Early
detection and ongoing control is advisable as mites can cause
considerable crop damage. Powdery mildew may also be a
concern in some hop varieties, particularly where air flow is
insufficient around a dense canopy.
HARVEST
Young hop shoots produced by an underground rhizome system which
is used for propagation.
Under good growing conditions, cones will develop along
the bines in succession and ripen at slightly different times.
For this reason, hand-harvesting ripe cones from the bines
and leaving immature ones to develop further can be carried
out on a small scale. Determining harvest ripeness can take
some experience, but mature cones will appear plump, fully
sized, soft and dry, light weight, slightly paler or yellow in
colour, and will have developed a high level of fragrance.
Immature cones are generally greener, firmer, and compact
and can be left to ripen on the plant. For larger scale hop
crops, all the bines can be cut back and removed at harvest
for easier cone removal leaving 90-120 cm at the base of the
plant for regrowth. Once harvested, the fresh cones can be
used immediately, however, shelf life is relatively short, and
the quality can decline rapidly under warm conditions. Fresh
cones can be stored in the refrigerator for a few days if neces-
sary but are best used within 24 hours. Most fresh hops, once
removed from the vines, are rapidly dried to maintain quality.
On a small scale, this can be done by laying the cones in a
cool, dry place, out of direct light for several days until fully
dried. These can then be stored in vacuum sealed bags either
under refrigeration or in the freezer before use.
Hydroponic hops production may be a relatively new
trend and an unusual plant for protected cultivation, but
their value is in the demand for high-quality fresh cones
that are best used within a day or two of harvest. With a
wide range of cultivars to select from and several differ-
ent training system possibilities, hydroponic hops are a
crop that has a promising future.
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