This last warm spring-like weekend turns the minds of many vegetable gardeners, and want-to-be gardeners, to spring planting. But, as experienced gardeners know, there’s still a good chance that we will experience frost or freezing temperatures into March. So, with the exception of cool-season vegetables such as Irish potatoes and greens, it’s still too risky to plant most garden vegetables because of the risk of the cold damaging young plants.

Mississippi State University’s Extension Service provides a helpful table of planting dates for common garden vegetables at http://msucares.com/lawn/garden/vegetables/planting/map.html

Note that Pearl River County falls into zones 1 and 2.

The dates recommended in the table are based on the median dates of the last spring freezes for stations in Mississippi. For example, based on statistics from the National Climatic Data Center (NCDC), the median date for the last freeze in Picayune is March 9^th. This means that in 50 percent of the years for which data for Picayune were available and analyzed, our last freeze of the winter had occurred by March 9^th.

Of course, that means that in the other 50 percent of years the last day with freezing temperatures occurred after March 9^th. Fortunately, NCDC also provides dates for 10 and 90 percent probabilities of 32 degrees occurring. Based on Picayune’s history, we know that there is a 90 percent probability that the last freeze will occur no later than March 28^th.

For some tender plants, frost can be just as damaging as a freeze. Frost can occur when winds are calm and weather station air temperatures, which are recorded a few feet above the ground, are as high as 36 degrees. The NCDC statistics show that Picayune’s median date for the last 36 degree temperatures in the spring is March 24^th, but there’s a 10 percent chance that we can get down to 36 degrees as late as April 11^th.

Complete statistics for Mississippi stations, including Poplarville and Picayune, can be found at http://www.ncdc.noaa.gov/climatenormals/clim20supp1/states/MS.pdf

Speaking of freezing temperatures, we will likely drop below freezing Thursday night in the wake of a cold frontal passage on Thursday. An even stronger cold front is predicted to move through over the weekend. That front could usher in some significant Arctic cold. As of this writing there are larger than normal differences between the predictions of the various computer models, so there’s more uncertainty than usual about the low temperatures, especially for early Sunday morning. Check the National Weather Service forecasts for updates as the week progresses by typing in your zip code at www.weather.gov.

No rain is expected through the weekend. The models are showing our next chance of showers on, you guessed it, Mardi Gras. The good news for both parade goers and parents with kids home from school is that a warming trend should be underway by Monday.

 

By Skip Ragney