There are many myths and old wives tales concerning fruit and vegetable crops that have become part of Kentucky lore. Several myths that still exist today involve grape coloration and fall frosts.
A number of grape growers believe that it is necessary to pick the leaves off the vine to expose the grape clusters to the sun so the grapes will color. This myth probably originated from growers removing leaves to improve air-circulation and reduce fruit rot. The truth is grapes — with the exception of the seedless Reliance variety — do not need sunlight to color.
In fact, the fruit will color just fine when covered. Home grape growers can staple a bag over each cluster, which keeps off birds, insects and diseases and reduces their spray program.
Frost has a tendency to concern many producers. Some people believe greens become poisonous after a frost. Greens like mustard, kale and collards actually develop a more enhanced flavor after a frost. Cool temperatures slow the internal respiration of the greens, allowing more sugars to accumulate, making them slightly sweeter. One exception, however, is rhubarb, which becomes toxic after exposure to a hard freeze.
Myths involving frosted sweet potato roots also exist. Many producers believe that sweet potato roots become poisonous after a frost, but they actually just rot. Sweet potatoes are warm season crops and will not tolerate a vine-killing frost.
Producers should worry about frost injuring the sweet potatoes where they attach to the vine. This injury prevents healing after the sweet potato is harvested leading to decay in storage.
For more information on fruit and vegetable production, contact the Franklin County Cooperative Extension Service, 101 Lakeview Ct., 502-695-9035 or email me, firstname.lastname@example.org.
Source: John Strang, extension horticulturist