Aspect: East, West, (and Romeo’s)

What light through yonder window breaks? It is the east, and Juliet is the sun.

Many people will recognize these famous lines  from Shakespeare’s Romeo and Juliet (Act 2, Scene 2) . However, it would take a true-and-total wine geek to understand how hearing that line—one of the most romantic ever written—inspired me to write a blog post about east-west aspect and its effect on a vineyard (and yet it did). Something about Romeo invoking the sun rising in the east reminded me of the concept of eastern aspect—as it was used in a recent discussion of the vineyards of the Côte d’Or—and here we are.

.

Wine students are well-aware that in the Northern Hemisphere, south-facing slopes (hillsides with southern aspect) receive the benefit of more direct sunlight (solar radiation/insolation) than other areas (those that are flat or facing north). These directions are flip-flopped in the Southern Hemisphere, where hillsides with a northern aspect have the sunshine advantage. The CliffsNotes version of north-south aspect is that if a hill faces the equator, it receives the bonus insolation.

Lesser known to wine students (but very important to realtors, as I learned) are the effects of eastern and western aspects, as discussed below:

Eastern aspect: These vineyards receive sunshine in the morning, when the sun’s rays are at their gentlest, and the ambient temperature is comparatively cool. This morning glow helps to dry out the vineyards from dew and overnight rain, helping to prevent fungi, mildew, and some disease. Eastern aspect can “kick-start” photosynthesis in the morning and can also help prevent vines from over-heating in the hot afternoons. Vineyards with eastern aspect tend to have lower maximum daytime temperatures, cooler overall ambient temperatures, and may experience delayed budbreak as compared to other spots.

Western aspect: Vineyards on west-facing slopes receive a good deal of sunlight during the afternoon—typically the warmest time of the day. Vineyards with western aspect may warm earlier in the spring and be among the first vines to undergo budbreak. Western aspect can be especially beneficial in areas near the coast and other places that are susceptible to wind and marginal weather. Western aspect can be a boon to late-ripening and heat-seeking grapes that require a lot of warmth and energy in order to fully ripen. However, It can be a challenge in areas prone to humidity, as the drying-out of dew-, fog-, or rain-related moisture will occur later in the day (as compared to east-facing vines).

Does that make sense to you, Romeo?

References/for more information:

• http://www.wine-grape-growing.com/wine_grape_growing/vineyard_site_selection/vineyard_site_selection_topography.htm
• https://www.eoas.ubc.ca/courses/atsc113/snow/met_concepts/07-met_concepts/07h-aspect-effects/
• https://www.gardenersworld.com/plants/types-of-garden-shade/

The Bubbly Professor is “Miss Jane” Nickles of San Marcos, Texas… missjane@prodigy.net