A Cook's Garden
Heirloom tomatoes: So good, so good for you
Thursday, June 10, 2010
Heirloom tomatoes, like Ol' Man River, just keep rolling along. It doesn't seem to matter that their yields are often less than those of modern varieties, or that some have less disease resistance. People continue to pay extra for them at farm stands and markets, and the enthusiasm for growing them is unabated. No one dares publish a seed catalogue without a diverse selection.
By and large, there is no contest between old and new when it comes to flavor. The oldies win and look glamorous, too, in all their shades of red, pink, yellow, green and black, many of them mottled, streaked or striped. For a gardener/cook, the work of growing them is justified by the show-stopping act of setting forth a splendid platter, assembled in minutes.
And consider this: All of them grow well in some particular part of the world where they were lovingly handed down from one generation to the next. Try a number of them and you're bound to find those that perform best in your garden.
It is now becoming more evident that old varieties are better for you as well. Much has been written lately about the "hidden hunger" produced by modern diets that are low in the essential minerals that humans need to get from their food.
A study done by Donald Davis at the University of Texas at Austin, based on Department of Agriculture data, documented the decline in the nutritional density of garden crops since 1950. The culprit: breeding that stresses higher yields and ease of transport as opposed to nutrition. You can impel a tomato plant to produce more fruits, whether by breeding or by using high-nitrogen chemical fertilizers, but its roots will take up only so much of soil minerals such as iron, calcium and zinc. In pumped-up tomatoes, flavor elements are diluted as well. No wonder modern tomatoes are less tasty.
This is not to say that the old varieties can't be improved. After all, they too are just a stage along the way, developed from varieties that came before them. A glance at today's catalogues shows that some breeders are going back to the mother lode of heirloom genetics.
The trick is to not stray too far from the old stock and continue to measure nutrient uptake, so that the fruits maintain a balance of trace elements. Far more research should go into this, but so far a lot of people are voting with their taste buds.
Damrosch is a freelance writer and the author of "The Garden Primer."