Most wine drinkers never think about
how the grapes that made their wine hang on the vine. Yet every
winemaker worries intensely
about the details of how to best trellis their vineyard vines
in order to get the optimum ripeness for their grapes. Grape
is, for us consumers, an unsung yet vital component of what
we finally taste in the bottle.
Wine and Sun
Hot Southern Oregon vineyards
get lots of sun
One of the world’s foremost experts on wine grape growing, Dr.
Richard Smart, has written that “wine is a product of sunlight.” It
follows, then, that to get the best wine the winegrower must make the
best use of sunlight. Trellising—how the grape vine is trained
to grow on wires or posts to expose its leaves and fruit to the sun—is
a key tool in achieving this goal.
Wine is essentially the product of
photosynthesis. The vine’s
leaves gather sunlight to fuel the process of converting carbon
dioxide in the atmosphere to sugars in the fruit. Additionally,
color, and flavor characteristics of the grape berry itself are
influenced by how much direct sunlight it receives.
It follows, then, that in order to
achieve the best possible fruit, the winegrower must manage
the way in which his grape vine’s
leaves and fruit are exposed to sunlight. This is the job that
Yet, there is no single “best” trellising
method, and diligent growers often tinker continuously with
how their vines grow
in order to learn what works best for their particular vineyard.
Over the many generations of wine history around the world, a number
of different trellis systems have been adopted as worthy methods of
capturing sunlight. These trellising variations are based on the unique
needs of different sites to manage factors such as weak or strong vine
vigor, to best capture the sunlight at different exposures and latitudes,
and even to make harvesting easier.
It is obvious to any wine drinker
that the climate of a growing region—what
is called the macroclimate—has a lot to do with the quality of
wine that can be made there. It is perhaps less obvious that each individual
vineyard site also has its own climatic variations—its mesoclimate—based
on local conditions such as slope, exposure, wind, rain, etc.
What few wine drinkers realize is that there is also a third kind
of climate that influences the quality of the wine they drink: the
microclimate that exists within the above-ground canopy of vine leaves
and fruit out in the vineyard. The quality of the climate immediately
surrounding each plant is very important in how the plant grows and
matures its fruit, and in the final character of the wine that is produced.
Trellising is also the most important tool in managing this canopy
microclimate for the best fruit quality.
The ideal in canopy management is
to find for each vineyard an arrangement of vine leaves on
the trellis that balances the many factors that influence
fruit quality—and therefore wine quality. These factors include
things such as: the number of shoots per vine and the way in
which they are placed on the trellis guide wires, the number
of leaves per
shoot and their orientation to the sun, the number of grape clusters
per shoot and their shading within the canopy, as well as many
Each different trellising system offers
growers varying opportunities to influence the fruit quality through
Trellis Systems in the Pacific Northwest
As anywhere else in the world, there
is no “best” trellis
system for the Pacific Northwest. Different climate conditions
(warmer or cooler), soil fertilities (invigorating or devigorating),
(own-rooted or rootstock), and varietals (early ripening or late
ripening) all require different approaches to trellising in
order to achieve
vine growth balance.
Even so, a number of different trellising designs have come into use
around the Pacific Northwest as ways to help improve the quality of
our grapes, and therefore our wine.
Often the highest quality wine comes from vines planted in thin,
relatively infertile soils. This means that the vines will tend to
have low vigor, which is desirable because the plant will tend to
put the majority of its energy into reproduction (creating fruit)
rather than simply expanding (growing larger).
The Guyot system, named after Dr Jules
Guyot, a 19th century French scientist, is one of the most
commonly used trellis systems in many of the world’s fine wine
regions, and is frequently used in Oregon, Washington, and
British Columbia because it is well suited
for low yield farming.
Though there are many subtle variations, the basic Guyot design is
relatively simple and easy to manage. It also has the flexibility to
allow easy modification based on local conditions, and has the important
advantage of producing small yields of high quality fruit.
From the vine’s trunk, usually
two fruiting canes are trained to grow in opposite directions
along guide wires that run just above
the trunk. Shoots that emerge from the canes are trained to grow
upwards by clinging to catch wires located above the canes.
In this system shoots can be manually placed for optimum spacing and
exposure to sunlight, and the fruit clusters can hang below the leaves,
receiving the benefits of good air circulation and controlled exposure
to direct sunlight.
Vertical Shoot Positioned Trellis
Similar to the Guyot system, the Vertical Shoot Positioned trellis
(often abbreviated as VSP) is designed to arrange shoots to grow
upwards across guide wires. Usually four fruiting canes are trained
to grow in opposite directions along two levels of wire. As in the
simpler Guyot, fruit hangs 3-4 ft. off the ground, and below the
raft of vertically growing leaves (see photo).
Scott Henry Trellis
The Scott Henry Trellis system can be considered a “native” Northwest
trellis design! Grower and winemaker Scott Henry (owner of Henry
Estates, in Umpqua, Oregon) developed this dramatic variation of the vertical
shoot positioned trellis as a way to deal with the fertile soils
Because the Henry Estate vineyards are located on productive soils
in the Umpqua River watershed, Henry had to find a way to encourage
his plants to better ripen more fruit, when all they really wanted
to do was grow more shoots and leaves.
Henry’s approach was to modify
a VSP trellis by dividing the canopy into two sections. Two
of the four fruiting canes have shoots
that are trained to grow vertically upward (as in a normal VSP
system). The remaining pair of canes have shoots trained to
grow downward, thereby
splitting the canopy into two sections (see drawing).
The Scott Henry Trellis creates additional
leaf surface area with which to feed the fruit, because the
upward and downward trained shoots
mean each cane’s leaves are more clearly open to the sun. This
also means the density of the canopy is lessened, thereby reducing
disease pressure and exposing more of the fruit.
Reproduced with permission from Henry
Estate - Thanks guys!
This system is one of the most popular ways of training grape
vines, and is more used in the warmer growing regions of Washington
(and in California) than it usually is in Oregon. This training approach
produces an arm of the vine permanently growing along a bottom guide
wire, with shoots emerging from the arm and trained vertically along
additional wires. Often, the shoots are trained to droop over the
top wire, with the grape clusters hanging roughly in the middle of
GDC Trellis at Academy of Wine
Geneva Double Curtain
This rather more complex trellis design is rarely seen in new
vineyards, though a number of older Northwest vineyards (particularly
in the warmer growing regions) sport it. In this design each plant
is made to grow two trunks, whose cordons are trained across twin
guide wires at a relatively high level from the ground. Shoots are
then allowed to grow hanging downward, curtain-like (see photo).
Like the Scott Henry system, the Geneva Double Curtain (GDC) divides
the canopy, thereby increasing overall exposure yet minimizing canopy
density. Also like the Scott Henry, the shoots are trained downward.
Lyre, or U Shaped Trellis
This approach to trellising is also uncommon in the Northwest,
but even so, some very fine wines have been produced using it. In
this design the vine is divided into two fruiting canes, each growing
in opposite directions, with shoots arranged to grow vertically upwards
across wires threaded through a U-shaped support system.
Like some of the other systems described
here, this approach results in a divided canopy—which means
(as we have seen) less density because the leaves and fruit
are spread across two curtains, increased
sun exposure, and fruit that is open to air movement, yet protected
from sunburn (see photo).
an understanding of trellis styles is hardly necessary to the
enjoyment of Northwest wine drinking, a knowledge of
how the grapes grow can help deepen your appreciation of the experience.
And, the next time you visit a winery or vineyard, take a
moment to study the vineyard. Can you identify which trellis
system is being
used? Why not ask the winery people what they know about
how they think it influences the character of the wine they