Monday, August 10, 2009

Looking at this Year

We're heading into the middle of August, the grapes are going through veraison--the coloring-- and I've been trying to figure out this growing season in order to be ready far harvest.

I think we've been a little drier than our friends to the east, enough to lower the downy pressure and increase the powdery pressure. I was getting a bit depressed a month or so ago about this season. After the last four years, I know we're due for a bad one, but I kept hoping we would be spared. I started looking at historical weather data from for York. (It's not quite Brogue, but close enough.) They even give GDD above 50F.

Here's what I gleaned from doing it. May was our second wettest ever since 1998. June was our coldest. July was drier, but not very warm. But then I noticed we were only 80GDD behind 2005 and 2007 at the end of July. 2004 had more than 250 more GDD than 2007/2005/2009 at this point. I am starting to think that our best years really come down to two things: warm and dry Septembers and dry Octobers. That's really the only pattern I could see.

So, my strategy this year has been to stay clean, open the canopy early, pull out all secondaries early, and hope for a good fall. At least I'm not as depressed as I was. Spraying every 5-6 days is a pain in the butt, though.

The wines should be at least nice, and if Mother nature cooperates at all with us this fall, look out, we could have some beauties.


  1. GDD? Never heard of it, but I have Internet access. :] indicates it stands for growing-degree days (for you other city slickers). I'd probably have known that if my livelihood hinged on Mother Nature. :]

    Does every farmer have to keep figuring it out each day, or is there some cool resource for that?

    I found this, but I'd hope there's something better:

  2. I guess I'll add this to my Christmas list. :]

  3. Okay, last post--I promise. :]

    Some decent links here...

    ...Led me here:

    ...But, I still don't see a daily running total of GDD. Maybe the next time I visit Allegro, Carl can show me how to hook the WeatherTracker I'll be getting for Christmas to my computer. :]

  4. Lee,

    Those are some really good links, and actually more involved than what I do. I cheat and go to There's a history data tab that I pull up for York. It's not quite Brogue, but close enough.

    For viticulture, we use base 50F for measuring GDD in this country. actually gives a monthly summary that I use. Basically what it is is a sum of the number of hours in which the max temperature reaches 50F or above. Winkler at UC Davis back in the 1950s (I think) came up with a scale that matched grapes to GDD. The scale is out-of-date now and a bit simplistic.

    So, I like to know what our GDDs are, just to get a sense on if we're behind our ahead of normal. Ultimately, I still think that rain and temperature in September make or break us.

    And, btw, that WeatherTracker looks pretty nice.

  5. Carl:

    Using another location as the basis for growing degree days can create some big differences by the end of the season. Depending on the location in York for the temperature recording, you could be as much as five degrees off at your vineyard. Add that up over the growing season and Allegro could be in another region based on the California system. Our vineyard in Lancaster County (about an hour from Allegro) is usually five degrees cooler than readings in Lancaster. That really adds up over the entire growing season. I would guess that you are probably cooler than the readings for York.

    Martin Keen

  6. Martin,

    Great observation. Weatherunderground actually has a location in Red Lion that I use more for daily updates, as it seems to be closer to what we experience here at Allegro.

    The York numbers are pretty close to ours. I've checked, and we're actually about 2-3 degrees warmer. What really changes is the amount of rainfall we get. A lot of storms seem to miss us. If they're coming from the west, they tend to start to break up around the south mountain area in western Adams county, and when they get to us they are in two pieces a lot of times. Half is heading along 30, and the other half is heading to Baltimore. Such was the case with the storm that took out Tucquan years ago with a tornado (according to John.) And just yesterday, I was in Columbia where it must have rained 2-3 inches in about 30 minutes, and when I got back to Allegro is was still bone dry.

    Who knows, but point well taken. Thanks!

  7. Hi Carl. I was reading this albeit a bit behind my time. I think you are right on. Forgetting all the calamity caused by wet springs and cool Junes. I think the most important is the 10 day span during flowering and fruit set and a dry cool September and October period. Also don't overlook the fact of your location. I can't place my finger on it but you have a certain microclimate that is vastly different then almost any other place in Pa. You can taste it in the wine and you said it last week when you emailed me that your harvest was a bit behind and grapes are still on the vines. Hell. Most folks are into full on vendange. Thats gotta be the reason John and Tim started there. Sounds silly and mystical however I think thats it. Plus Carl its in the glass. It tells you everything you want to know. Salute!

  8. Anthony,

    I agree with what you wrote. Flowering and fruit set are critical, especially for the start of the fruit-bud initiation process. Without Sunshine on the emerging buds around bloom, those buds will be fruitless next year. This year's bloom was really slow--over three weeks for Chardonnay!--so, I'm a little worried about 2010 yields.....

    As a side note about why my grapes are still on the vine...I'm a bit more stubborn--or foolish--than some of my colleagues. Our fruit seems to ripen a bit quicker here than in most PA places. But I also tend to let stuff hang longer than most. I think I'm the only one letting reds hang past leaf-drop....and I mean, really long past leaf drop.

    Pulling the trigger now (late September on some varieties is necessary of there's disease and/or weather pressure. So far, we don't have either. So we're still hanging...



By posting on here, you are guaranteeing that what you say here is worthwhile and worth saying. And something that you would say in the presence of your mother. If not, I will be forced to remove it.