Episode Details

If you’re reading this as May turns into June, and you live in the West, you know you’re going through a heat wave, including triple digit temperatures in parts of California. A more widespread - and longer - heat wave is expected in mid-June. And, long range forecasts are calling for a much hotter summer (July through September) than usual throughout most of North America.

This is not good news for your south and west facing backyard tomatoes, especially.

Give a listen to today’s newsletter podcast clip (a short one) from Episode 383 of last March, the 2025 Tomato Preview Show. Don Shor of Redwood Barn Nursery in Davis offers tips on protecting your young, west-facing tomatoes (as well as bell peppers) from developing sunscald or sunburn during an extended heatwave.

It’s a technique that allows commercial tomatoes to be picked early in their life, stored, possibly treated with ethylene gas, and then shipped to grocery stores after they’ve reddened up and gotten a bit soft…with parts of their stem still attached. These tomatoes receive a premium price, because they are labeled as “vine-ripened”.

Processors and grocery stores insist this fits the definition of “vine-ripened”. Actually, there is no legal definition of “vine-ripened”, according to the USDA. The closest they come is in their “standards” for a mature tomato, which might come as a shock to you who grow backyard tomatoes.

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From the USDA’s “United States Standards for Grades of Tomatoes on the Vine”:

§51.2172 Mature.''Mature'' means that the contents of two or more seed cavities have developed a jellylike consistency and the seeds are well developed. External color shows at least a definite break from green to tannish-yellow, pink or red color on not less than 10 percent of the surface.

You may have assumed that those grocery store “vine-ripened” tomatoes were picked red and shipped immediately. You may have noticed that the tomatoes had a “tomato aroma”. Actually, if they still have a piece of the vine attached to them, that is the part that is emitting the aroma, according to “America’s Test Kitchen”. They also quickly point out, however, that “…in blind side-by-side tastings, my colleagues and I have never been able to consistently find a difference in flavor” between on-the-vine and ethylene-ripened tomatoes.

They quote a study that reaffirms their findings. That study was published in “The Journal of Food Science - a Publication of the Institute of Food Technologists”. It was conducted primarily by the staff of Rutgers University Food Science and Plant Science Departments, with support from the New Jersey-NASA Specialized Center of Research and Training. Do any of these firms have ties to the commercial tomato industry? I’ll let a newspaper or magazine with a team of researchers try to track down that answer.

The title of the study was: “Quality Comparison of Hydroponic Tomatoes (Lycopersicon esculentum) Ripened On and Off Vine”.

Before moving on, a clarification for you real tomato heads from NeetPrep.com (which bills itself as “India’s #1 Classroom Test Series”) regarding the question of the correct biological name for the tomato:

“In 1753, Linnaeus placed the tomato in the genus Solanum (alongside the potato) as Solanum lycopersicu