I’ve been harvesting ripe tomatoes more-or-less continuously over the past week.
Accordingly, it’s about time I admitted that my prediction of a period of no ripe tomatoes, due to excess heat, was wrong. And it’s time to do the autopsy.
In 2020, we had a few weeks during which tomatoes did not ripen. That was attributed to the excessive heat. Below is my analysis of the temperatures in my area for summer 2020 and 2021. My conclusion is that nighttime lows in excess of 70F or so (other references say 72F) will prevent tomatoes from ripening.
We were predicted to have another stretch like that this past week or so. But, as it turns out, the prediction was wrong. Not hugely wrong — days and nights have still been warm in Northern Virginia. But wrong enough to allow tomatoes to continue to ripen.
Here are the actual observed temperatures, at the same location as the graph above, for July 2022, through yesterday. I’ve sketched in a blue line at 72F:
As you can see, we’ve only had an occasional night that met the 72F minimum temperature criterion. By and large it has remained just barely cool enough for tomatoes to continue ripening.
So I can add this non-test to my non-test of growing cucumbers and squash in an insect-proof enclosure. Last year I had a plague of insects that attacked those two plants. This year I have none. I therefore can’t tell whether or not growing them in an enclosure protected them. And add that to my non-test of citric acid and copper sprays to prevent powdery mildew on cucurbits. Last two years my plants were overrun with powdery mildew. This year, I have to look hard to find any at all. So, again, I have no clue whether or not these treatments work, because the disease appears to be absent from my garden this year.
