Archives for posts with tag: temperature distribution

Just before shutting down my computer this evening, I took one last look at the weather forecast.  Some people compulsively check the stock market and others keep close track of baseball (and other sports) scores.  I’m addicted to the weather.

I was rudely surprised to see that the National Weather Service had posted a Frost Advisory for later tonight and into tomorrow morning.  Where did this come from?  Yes, the forecast has been calling for cooler temperatures, with highs in the 70s and lows in the 40s and 50s, but frost?  Really?

And what am I supposed to do with this information, at such a late hour?  The warning was not posted until about 6:00 pm.  That gives me only an hour before the sun sets.

Not that more warning would have been particularly useful.  Although the number of plants remaining in the garden is diminishing, there are still several growing strong.  And all of them are either tall (e.g., the tomatoes and string beans) or spread out (the squashes).  It’s not like I can easily throw a tarp over the entire yard.  (Well, I suppose could do that, but it wouldn’t be easy.)

I imagine that some farmers will be firing up their smudge pots tonight.  A common sight in orchards and vineyards, these oil-burning heaters produce a high-volume of slow-rising smoke—some call it artificial smog—which I always thought enveloped the plants and slowed their cooling.

Turns out they work more like the large fans that other growers—such as an apple orchard we visited last weekend—will be switching on instead.  Both the heaters and the fans circulate the lower levels of the atmosphere, moving colder air at the surface upwards and bringing down warmer air from the overlying inversion layer.

I love the idea of having one of the monster fans in my backyard (I could connect it to my propane tank) but I suspect they are very expensive (no, I’m not seriously considering it).  So this time, we’ll take our chances and do nothing.  Despite the advisory, the forecast low is 44 degrees, well above freezing.  I’m not too worried but we’ll see how things look in the morning.

If I look at the average temperature over the last two weeks—78 degrees (high) and 57 degrees (low) since May 28—and the average rainfall during that period—1.30 inches per week—they appear to be almost ideal conditions for growing vegetables.

But if I look at the actual distribution of temperature and precipitation, the situation is less than favorable.  At the end of May and beginning of June, there were three days with temperatures at or near 90 degrees which were preceded and followed by days with highs around 70 and lows below 50.

Similarly, almost half of the total rainfall over that two-week period (1.03 inches) fell on one day; a large part of the remainder (0.44 inches) occurred the day before (as part of the same storm system).  That’s almost 1 1/2 inches of rain in a 36 hour period.

(These numbers are based on reports from the Weather Channel website; our conditions could be very different.  One of these days, I might get a high/low thermometer and rain gauge and place them in the garden.)

The extremes of temperature (at either end of the spectrum) can easily kill a plant, especially a young, recently-transplanted one.  And rainfalls of greater than half an inch (over 24 hours) are a waste of water, most of which runs off.  Heavy rains can also damage plants (due to impact) and often cause flooding or erosion.

I’m not complaining—there would be no point—but it leads me to imagine the garden of the average family from The Phantom Tollbooth, by Norton Juster.  Most likely tended by the fractional (0.58) child, the garden would probably be relatively small (being of average size) but I expect that the growing conditions would be good (even if, well, average).  On the other hand, the quality of the average family’s garden would be less than exceptional (by definition) so it would be something of a trade-off.

Always striving for the perfect tomato or stellar Sugar Snap pea, I’ll take my chances with our sometimes less-than-ideal conditions.