How to Grow Tomatoes with Great Flavour

17 March 2016, written by Barbara Pleasant

Tomatoes are many gardeners’ favourite summer vegetable, and we look forward to bountiful crops of tomatoes that surprise us with their fruity notes, amaze us with their juiciness, and delight us with their varying colour and forms.

This is how it usually happens, because organically grown tomatoes of most of the popular garden varieties taste very fine indeed when grown in good sun and given reasonable care. But sometimes I hear from gardeners who say their tomatoes lack flavour, which is always the start of a good mystery. Will it be nature (poor choice of varieties), nurture (incorrect cultural practices), hideous weather, or all three?

Start With Great Tasting Tomato Varieties

The best guesses as to how many tomato varieties exist in the world today range between ten and twenty thousand, so an obvious flaw of any variety trial is that it cannot include all of them. But even when university field trials or community tomato tasting events include only a few dozen varieties, the same ones tend to come out on top, and they are all little cherry tomatoes.

For example, in the UK, tomato tasters at BallColgrave's Summer Open Days have given the highest taste ratings to ‘Sweet Aperitif’, ‘Sun Gold’ (or ‘Sungold’), and ‘Sweet Million’ year after year. In the US, ‘Sun Gold’ has long reigned supreme in blind taste tests, but lately ‘Sun Sugar’ has been gaining an edge, and some gardeners find that it is more crack-resistant than ‘Sun Gold’. Bright red ‘Sweet Aperitif’ is a recent arrival in US gardens, and it is quickly developing a following for its bright, tangy flavour.

We could discuss great tasting tomato varieties for years, but my point here is that these top-rated cherries are a logical starting place for gardeners with a tomato flavour puzzle on their hands. If your ‘Sweet Aperitif’ or ‘Sun Sugar’ tomatoes lack addictive zip, you will know that variety is not the problem.

Growing Tomatoes for Flavour

Scientists have traced the taste of homegrown tomatoes to more than 24 flavour compounds, some of which wake up our noses so we can better taste tomatoes’ sweet or fruity flavours. Plants that are large and leafy when they set fruit do the best job of socking away flavour compounds when the crop is ripening, so spoiling plants when they are young is a sound strategy. But once the fruits have set, it is best to switch gears and let the plants push themselves a little to make their crop. Some of the most remarkable flavour profiles in tomatoes are associated with slight nutritional and water stress late in the season, when the fruits are ripening.

In some solved missing-flavour mysteries in which I was involved, the problem was wrongful use of fertiliser and water. It’s true. You can take a perfectly capable tomato seedling and stress it half to death when it’s young, and then almost kill it with kindness when it reaches maturity, and go on to harvest tomatoes with hardly any flavour at all.

It should be the other way around, in that the time to pander to plants is when they are young, and it should not be only about water and nutrients. Tomatoes run on sun, so the more abundant bright sunshine they get, the better they will grow. You can support fast growth with supplemental feedings, but a strong supply of sun comes first.

Exploring the Salt Solution

Now for something weird, which might be a worthwhile experiment for gardeners who are growing tomatoes in sandy soil – using sea salt to bring a special spunkiness to tomato flavour. Coastal gardeners who use kelp in mulch or compost are already doing this, because small amounts of sea salt come with the kelp, but it may be that other gardeners should bring a jar or two of sea water home from the shore, dilute it with four parts water, and use it as a one-time drench for half-mature tomatoes.

You may see results, but don’t expect miracles. When New Jersey researchers studied the method, they found noticeable results in one field, but not in another. Then there is the problem with salt buildup in soil in general, which can only be aggravated by adding more salt. But it may be that tomatoes like their salt. Human urine contains so many salts that improper dilution can lead to injured plants, but it is quite usable as a high nitrogen fertiliser when diluted with 20 parts water. I only bring this up because of a recent Finnish study in which diluted human urine was used as the primary fertiliser for tomatoes. The plants produced just fine, with no losses in tomato flavour, perhaps due in part to the salinity of the fertiliser solution.

Barbara Pleasant