How Is Wednesday Morning Shaping Up at This Point? And, Some Strategy Points for Row Cover Use (2:50pm, Sun, 4/3/16)
Dear Agents, Agronomists and Growers,
I know everyone is trying to “root out” what may be happening in their area this Wednesday morning as far as a potential damaging frost.
Since March 31st we have been “examining” this event on a daily basis. Here is the very latest minimum temperature map issued today (Sunday) for Wed, April 6th:
Fig. 2. The minimum temperature map issued on April 1st for April 6. When this was issued on April 1st, things looked quite a bit more threatening … if you compare this map to the one above, you will note that areas like FAY (Fayetteville) are no longer under threat of sub-freezing temps on Wed morning. However, this region may still see a frost on Wed morning!
Let’s now check AWIS Detailed forecast (below) to see what Fayetteville may actually experience on Wed (Table 1).
Table 1. From the 10-Day Detailed Hourly Weather Forecast (just below), I clicked on Fayetteville and then took a screen shot on my computer of Wednesay’s forecast. It is important to note that even though it will not be going below the freezing point, the air temperature will still be 33 F, and we all know that with an air temp at weather shelter of 33 F, you can easily see frost on ground! And, sure enough, AWIS is forecasting a Frost at 5 am this Wed morning. If you are now harvesting, sprinkler irrigation is not an option. You should rely on row covers.
Row cover strategy this week
What I really like about the 10-Day Detailed Hourly Weather Forecast is how it also provides a lot of “context” about the kinds of weather conditions you will be experiencing before and after a cold event. One of things that growers constantly struggle with is how to time a row cover application for a frost that may be 2-3 days out? This is where it really helps a lot to have a reliable forecast, such as provided by AWIS, for so many locations across MD, VA, NC, SC and GA.
Art and Science:
Now, this is where the “art and science” of strawberry growing comes in! And, I would probably argue that cold protection in strawberry is at least 50% the art of knowing “when to act.” So, let’s take the information in the Fayetteville AWIS report for Sun-Tue and really look at some of the issues that will confront growers in this area in this early week:
Table 2. Please note that winds are going to be very high most of the day Monday, and will continue to increase in speed on Tuesday! This is not a good thing! The grower would ideally like to apply the row cover to protect his/her crop the afternoon prior to the evening/morning cold event. In this location winds will still be at 15 mph at 5 pm on Tue. I know that some of our more experienced growers have worked out excellent techniques for unfurling covers in these kinds of winds (they fasten the covers down on the windward side of the beds, and let the wind sort of “float the cover out” over the rows), but I also know of newer growers who don’t like to experiment with trying this technique. For the let’s play it safe crowd, it looks to me like your best option for applying row covers in Fayetteville area for a Wed morning frost might be to apply them on Monday morning by 9 am (winds will still be below 10 mph).
So, please carefully study the detailed forecasts below for city/town near your farm, and perhaps you also subscribed to Skybit this season, and with both of these instruments, you can make a very well informed, practical decision on how best to manage your row covers in the coming week! Good luck!