Pass the Salt for Tasty Tomatoes

By Steve Reiners, Professor and Chair, Horticulture Section, Cornell University, Cornell AgriTech. This is part of a series of columns that he wrote about vegetable gardening during the pandemic that ran Spring-Summer 2020. Read more articles from 2020 | Read later articles in this series.

July 24, 2020

How can you get the best-tasting tomatoes from your garden?  Obviously, you start with a variety that we know from previous experience is good.  Then hope for lots of sun, well timed rain, and warm but not hot temperatures.  But is there anything you can do now to maximize flavor?

Does location make a difference?  I’m sure many of you have heard about the great “Jersey tomatoes” - the supposedly superior tasting fruit from our southern neighbor.  Their superior taste is attributed solely to the fact that they are grown in the Garden State.

Now I’m from New Jersey.  I lived there for almost half my life.  But I have to say, I just don’t buy it.  And I even have proof to back up my claim.

Every year, Rutgers celebrates their signature commodity with a giant field day at their research farm dubbed the “Great Tomato Tasting.”   There, they celebrate all things tomato and especially the superiority of their Jersey tomato.   In 2012, having tired of their claims, I challenged them.  I would put a New York-grown tomato up against theirs and may the best tomato win.

We didn’t have many rules other than to use the same variety, a popular variety grown in both states.  But it was up to us how we wanted to grow it in terms of soil types, fertilizers and pest management practices. I grew mine at Cornell AgriTech in Geneva and didn’t do anything special.   In late August, I picked about 20 fruit and headed south to see if we could compete with their state specialty.

We had more than 200 people taste each and we had a clear winner.  My New York tomato!  And although I love nothing better than to share this news with the tomato growing public, I do need to be fair.  There may have been a variable more important than location.

I picked my tomatoes at close to peak ripeness, kept them at room temperature for two days and by the time we had the taste test, they were just about at the perfect eating stage.  The Jersey tomatoes probably had one or two days to go before they would be at their peak.  So, it was a win for New York, but one with an asterisk next to it.  If the contest were a couple days later, their tomatoes might have caught up in the flavor department, while the ones I brought would have been past their prime.

Tips for maximizing flavor

But there are some lessons here:  Harvest tomatoes when they have vine ripened but before they soften.  Once harvested, keep them in the dark or away from bright windows.  They do not need sunlight to ripen or for their flavor to reach its peak.  And never, ever place tomatoes in the refrigerator.  Temperatures below 55F will destroy their flavor.

Can the way you fertilize your tomato plants have an impact on flavor?  My colleague at Rutgers, Joe Heckman, thinks that may be possible and he believes one nutrient may be the key – sodium.

Sodium was routinely added to soils when sodium nitrate (Chilean nitrate) was used as a source of nitrogen.  But since the 1940’s other non-sodium nitrogen sources have been used.  And that’s been a good thing as we know sodium can have detrimental effects on soils.

But research in Israel and Italy suggest that tomatoes from plants treated with small amounts of brackish, saline solutions were preferred in taste tests, possibly due to increased acids, sugars or other components.  And Heckman did some research in New Jersey with similar results.

He actually applied some ocean water, about a quart and a half, as a foliar drench to each plant.  There was some leaf burning from the salt, but the plants recovered quickly.  And in an informal test, the ocean-water tomatoes tasted better.

There is even a fertilizer called SEA-90 that is nothing more than sea salt that gardeners can use for this purpose.  Just make sure you don’t apply too much as sodium is not good for our soils or plants.  But it may give you a tastier tomato

And it might not be the sodium having a direct effect.  Salt stresses plants.  And the stress may improve flavor as it has an impact on flavor compounds.  Some growers in the southwest actually stress plants by limiting irrigation.  And we recommend this for cantaloupes and other melons to maximize their sweetness.

This week in the garden

Want a nice pungent onion for cooking?  Give the plants a little extra sulfur by sprinkling half a teaspoon of Epsom salts by each bulb.  It provides both magnesium and sulfur.

I harvested my first potatoes this week.  Just a few plants as the “new” potatoes are still only about half the size they will eventually get.  You can get this first harvest when you see the potato plants flower.  But wait until the all the vines start to yellow before making the final harvest to get the biggest spuds.