The latitude-temperature index tends to be more accurate than heat units in predicting
succesful grape varieties in cooler districts. Here in Gambo our L-T index was 214 for 2004 despite it being a very cool
summer. Suitable grape varieties to try would be those in Class A-1, A-2, and B.
| Class |
Heat Unit Class Equivalent |
L-T Index |
Description |
Wine Type & Grape Varieties |
Varieties Predicted As Suitable |
| A-1 |
I |
Less than 190 |
Very Cool |
Light fruity wine, low alcohol wines |
Gewurztraminer, Madeleine Angevine, Reichensteiner, Perle,
Schonberger, Muller-Thurgau, Tromphe d'Alsace |
| A-2 |
I |
Less than 190 |
Cool |
Premium white wines, light red wines |
Pinot gris, Pinot blanc, Pinot noir, Pinot meunier, Chasselas, Sylvaner,
Chardonnay, Faber, Kerner, Scheurebe, Auxerrois, Aligote, Bacchus |
| B |
I |
190 to 270 |
Cool to warm |
Full premium whites, premium reds |
Reisling, Pinot noir, Chardonnay |
| C |
I |
270 to 380 |
Warm |
Premium reds |
Cabernet Sauvignon, Cabernet franc, Merlot, Malbec,
Sauvignon blanc, Semillon |
| D |
II |
Greater than 380 |
Warm to hot |
Standard and bulk wines |
Carignane, Grenache, Shiraz, Thompson Seedless,
Cinsaut, Zinfandel |
Table from Viticulture 606, University of Guelph
A HOBO (weather monitoring device) is placed in the vineyard
to monitor minimum/maximum temperatures and humidity more accurately. Soon
we will have a better picture of the meso climate here.
There is no lack of sunshine during the summer months here in Gambo. For the norm we are not foggy here at all, even when
there is fog in Gander and across the bay, we seem to be in some kind of
trough. At times, too, it may be raining in Gander but it passes us by.
Winter conditions here in Gambo surprise many people. Newfoundland usually conjures
up visions of icebergs, snow storms, wind, fog and really cold temperatures. We may experience
these elements to some extent but winters here are not that cold by Canadian standards.
St John's is ranked third of the warmest cities during Canadian winters, behind Victoria
and Vancouver. Winter comes gradually to Gambo, with fall usually being very pleasant.
February appears to be our coldest month, temperatures in some years may dip to -23°C but with the amounts
of snowfall we experience this is not a problem as snow is a very good insulator for
the vines. We are considered a USDA Zone 6, Canada Zone 5 based on our winter lows.
|
If low temperature is higher than
|
Injury hazzard is
|
Suitable varieties
|
|
-2°C
|
very low
|
almost any
|
|
-20°C
|
low
|
most northern vinifera
|
|
-23°C
|
moderate
|
hardy vinifera/moderately hardy hybrids
|
|
-26°C
|
high
|
hardy hybrids/most American
|
|
> -26°C
|
very high
|
hardy American varieties
|
MacPherson
& MacPherson in The Natural Environment of Newfoundland Past & Present,
noted that during a 30 year period
temps greater than -25°C occurred 0 times,
temps greater than -20°C occurred 3 times,
temps greater than -15°C occurred 19 times.
Winter Low Temperature and Snow Cover For Gander
| Year |
Lowest Temperature and Month Recorded |
Amount of Snow Cover When Low Occurred |
| 2003 |
-22.6°C Feb. |
66 cm |
| 2002 |
-23.1°C Feb. |
108 cm |
| 2001 |
-19.5°C Feb. |
114 cm |
| 2000 |
-17.4 Mar. |
43 cm |
| 1999 |
-18.7°C Jan. |
24 cm |
| 1998 |
-23°C Jan. |
21 cm |
| 1997 |
-22.8°C Mar. |
45 cm |
| 1996 |
-21°C Jan. |
55 cm |
| 1995 |
-22°C Feb |
127 cm |
Grape Varieties
There are many grape varieties available for cool climate growers.
Recommended varieties for Newfoundland could be the very early to early
types. It may be possible in suitable areas to grow some of the more winter
hardy vinifera. Other areas would be suited to many of the French/American
hybrids. Research is needed to determine which variety or varieties are
best suited to Newfoundland's unique and varied growing conditions.