At the end of the summer, my father always stripped the upper leaves off his tomato plants so the fruits would mature more quickly. After all, he reasoned, exposing the leaves to the sun makes them ripen, so getting rid of the leaves shading his tomatoes ought to ensure an earlier harvest.
And he wasn’t alone in this belief: it was common practice 50 years ago and is still done by many gardeners to this day. But they’re wasting their time.
Tomatoes ripen when they are ready to mature, period. You can’t do much about it. The weather is a factor, of course: they do ripen most quickly at warm but not hot temperatures, but what can you do about that?
The Two Tomato Test
It’s easy enough to prove that exposure to sunlight doesn’t help tomatoes mature. Just harvest two tomatoes that have started to turn red but aren’t quite ripe. Place one in a brown paper bag, perhaps putting it in the pantry, and leave the other exposed, setting it on a sunny windowsill. You’ll see that both mature at the same time and yet the one kept in the paper bag received absolutely no sunlight.
Sun-scald and Insipid Taste
The worst part of this myth is that not only stripping tomato plants of their leaves doesn’t help the fruit mature, it can be downright harmful.
Fruits that were completely shaded by leaves, then suddenly exposed to full sun, may actually suffer sun-scald (the plant equivalent of sunburn) and, although they are still edible, won’t be as presentable.
Also, it is foliage, because it captures the sun’s energy and converts it into sugar, that gives tomatoes their sweet taste: if you strip the plant’s leaves, your tomatoes won’t be quite as tasty!
Of course, you can remove yellow, brown or diseased leaves (that’s another story entirely), but leave green leaves intact if you want the tastiest, prettiest tomatoes in town!