People from all over North America have discovered the attractions of the Jersey Shore in summer. Aside from the sand and surf, people are attracted to the sun, the moderate temperatures, and the long summer season.
These same climate conditions benefit the growth of our grapes. In the two river area, we are nearly surrounded by water. (See Geography for more info) From New York Harbor and Sandy Hook Bay on the north, to the two rivers themselves on the south, to the Atlantic Ocean on the east, these large bodies of water moderate our temperatures so that we are sheltered from the hottest heat of the summers and the coldest cold of the winters. This moderation of our climate provides for the long growing season that premium wine grapes require to reach their fullest potential. Our average growing season is between 210 and 230 days long, and our average heat summation is over 3200 growing degree days. This compares favorably to the best growing regions in the world, and it is similar to parts of the Napa valley and Bordeaux. The water also changes the weather patterns locally, breaking up summer thunderstorms before they reach our area. On average, we receive about 5" less rain per year than the rest of New Jersey, and the biggest difference is in the critical late summer months.
One of the most important features of our local climate is the moderating influence of the water on our absolute low winter temperatures. As cold North winds blow across New York Harbor and Sandy Hook Bay, they are warmed by the waters, so the air temperatures are markedly warmer before they blow across our vineyards. This is critically important for fine European varieties of grapes, many of which cannot tolerate temperatures much below 0F. Over the last 10 years, the temperature at our vineyards has never dropped below zero, even when places as close as Freehold and Newark have recorded temperatures as low as -10 to -15 degrees, temperatures that would kill most vinifera grapes back to the ground.
In the Spring and Fall, too, the water improves our climate. In Spring, grapes bud out pretty early compared to many other crops. This means that they can be sensitive to late frosts. Frosts as late as mid-May are common in many parts of the East, even south as far as the wine growing regions of Virginia and the Carolinas. The water surrounding us helps us in two ways: In early Spring, the cool waters delay budbreak for a critical week or two, until most danger of frost is passed. Later in the Spring, the (relatively) warm waters tend to warm the air enough to prevent late frost. The reverse happens in Fall, where the warm ocean and bay waters extend our growing season out as far as Thanksgiving in some years, while many other Eastern vineyards must pick before the end of September to avoid early frost damage.
Finally, there is the seabreeze. The same onshore breeze that keeps the beaches cool and comfortable all summer long blows up the slopes of our vineyards and keeps our grapes cool as well. Even more importantly, the constantly moving air suppresses mold and mildew, two of the biggest enemies of grape vines in the East. As a result, we can use less chemicals on our vines, and the grapes suffer less from mold damage.
While the politicians debate about whether or not the climate is changing, and whether people are responsible, agriculturalists are recognizing that the climate has already changed significantly over the last 100 years or so, and that the change is accelerating. Since grapevines can have lifespans of decades or even centuries, advance planning is an important part of viticulture. In short, we don't particularly care who is at fault (if anyone). We see change happening and must plan for it in our designs and crop selections.
Of course global climate change will also affect our local growing conditions. Over the last 10, 50 and 100 years, vineyards around the world have recorded noticeable increases in average temperatures, wintertime low temperatures, onset of budbreak, and length of growing season. We have noticed a similar trend and as it continues, we expect our area to become even more suited to growing the most premium of winegrapes. Winegrapes are very sensitive to climate change, because each variety is ideally suited to very specific conditions. These site-specific characteristics have developed through several millenia of careful selection by local vineyardists. Examples of the sensitivity of wine quality with climate abound. In France, the difference between 1st growth Bordeaux and 2nd or 3rd growth can be no more than 50' high hill raised from the local countryside. On the hill, the grapes are excellent. Off of it, they are still very good, but not quite as good. With temperatures rising by 3-5 degrees Fahrenheit over the next 100 years, this will have dramatic impact on the regions where grapes can be grown, and which grapes are selected for each region.
When the ideal growing conditions for each variety are overlaid with the temperatures predicted by some of the most advanced climate models, we see that most of North America will actually become too hot for winegrape production in the next century. The ideal growing regions will shift from the West Coast and Midatlantic states to the Northeast, with a thin sliver of suitable climate on the West Coast and Northwest. New Jersey may yet be the next Bordeaux! Even over the past 10-20 years, New Jersey farmers have seen less frost damage, earlier budbreak, and warmer winters. As it stands now, we have enough heat and long enough growing seasons to ripen the Bordeaux varieties and some of the other warm climate grapes. As the warming trend continues, we expect to see clear improvements in vine health and hardiness, with consequent improvements in wine quality.
In Agricultural lingo, there are three distinct climate zones that characterize the growing conditions for a particular vine: macroclimate (or simply climate), mesoclimate, and microclimate. The macroclimate is the general climate of the region, modified by large local influences such as mountain ranges, large bodies of water, etc. We discussed that above. The mesoclimate is more local, and consists of those local features of the topography such as hills and valleys, streams and ponds, treelines, slope of the site, and other features that can affect the climate in a specific vineyard, sometimes creating several distinct mesoclimates within a single vineyard. We'll discuss this one here. Microclimate is the actual weather within the grapevine canopy, and sometimes extending out a foot or so around the canopy. This is the climate that represents the actual growing conditions that the the individual grapes and leaves see on a daily basis. We discuss that one on our Grape Culture page.
Many of the vineyards in our area benefit from a nearly ideal mesoclimate. In fact, our terrain is one of the main reasons that we think the area has the potential to produce world class wine grapes.
The hills bordering the Navesink River rise over 200 feet above sea level. Hillsides create their own mesoclimates, and provide great benefits for viticulture. Some of the most famous vineyards in the world are separated from their less noble neighbors by nothing more than a low hill. Nowhere else on the East Coast is there such an ideal combination of a moderate maritime climate with tall hills to enhance the benefits of that climate.
Hills benefit grape vines primarily by providing air and water drainage. Mature grapevines do not require much water to thrive, and frankly, they get more than they need in our area. Planting grapes on a hillside allows excess water to drain away from the root zone quickly and prevents waterlogging and drowning the grapes. Quick drainage also reduces the effects of late rains that can saturate the grapes and lower the intensity of sugars and flavors. Good drainage also enhances the vines' ability to resist extremely cold winter temperatures, and improves their hardiness.
Air drainage is even more important than water drainage. The main benefit of air drainage is frost protection, both in Spring and Fall. Many early and late frosts occur overnight on calm, clear nights when heat radiates out from the soil, and very cold air settles on the ground. In some cases, the freezing air is only a few feet thick, but if a vineyard is located in a valley, the grapes are submerged in a "lake" of cold air and they freeze. Frost in late spring can freeze juvenile flower clusters and destroy an entire year's crop. Early Fall frost shuts down the vines and prevents any further ripening. Hillsides allow this layer of cold air to run downhill off of the vineyard to be replaced with warmer air above. This prevents frost on all but the coldest nights. In recent years, we have experienced spring frost in Monmouth County as late as May 26, but the temperatures at our vineyards have been above freezing during all of these late frost events. In Fall, we generally see our first killing frost no earlier than mid-November. This allows us extended "hang time" necessary to develop the best combinations of sugar, acids, and the fruit flavors that develop in cooler weather.
Hills also enhance natural wind currents. Even when the wind is calm down at water level, on top of our hills, the wind is always blowing. As explained above, this constant air movement keeps the vines dry and suppresses mold and mildew growth on the leaves and grapes.