Tuesday, September 2, 2008

All About Tomatoes

This week's newsletter essay, by Farmer Richard:

Tomatoes are a bit of a challenge in our normally moist valley. The moisture favors the leaf diseases that cause leaves to spot, brown and die before they can put full flavor into the fruit. After some years of tomato failures, we have developed a dependable production system and we search for varieties that are suitable for our region, with great flavor and disease resistance. Many conventional and commercial tomato varieties bred for consistent size and shape are suitable for mechanical picking and long distance shipping, but to the detriment of flavor.

We plant two crops of tomatoes in our greenhouses on March 20 and April 20. In mid-May, we transplant the first crop into a green plastic covered raised bed, which helps to trap heat and promote growth. We put down mulch between the beds for weed control and for a dry picking path. The tomatoes are planted only 12 inches apart. We put a wooden stake between every three plants and every sixth stake is a stronger steel post with steel at the ends. There are steel “gates” every 150’ for picking access. Three weeks after planting, we prune all suckers except the one below the first flower cluster. That gives us two main stems per plant. When the plants are about 12 inches high we weave the first string between the stakes to hold the rapidly growing tomato plants upright.

Rapid growth is somewhat dependent on hot days, but also on good moisture. Every raised plastic covered bed has a drip irrigation line under it. Every week we give the tomatoes’ root zone a good drink of water with liquid fish and kelp nutrients added. This produces rapid growth and many large tomatoes. Every week we add a string to both sides of the vines, looped tightly around each stake. This process includes a ball of twine on the string-tiers waist, with the twine threaded through a small oak stake to give the person tying a longer reach over and around the stakes. Fast tying involves great skill and results in a beautiful wall of tomatoes off the ground, high and dry for minimizing disease. Picking is much easier and faster with this system as well.

Tomatoes are categorized as either determinate (one crop all at once, topping off at a specific height) or indeterminate (plants that produce vines that don’t top off and will continue to produce until the first frost). When indeterminate tomatoes continue to grow above the 5’ stakes, we cut the tops off as a way of staying “stop & ripen” to the many tomatoes already set on the plant.

Good, rich, fertile soil and lots of water are essential, but so is the genetics of the seed. There are thousands of tomato varieties, but they vary greatly in resistance to disease, color, flavor, sugars, and acid balance. High acid is required for canning. A nice balance of flavor, sugars and acid may be the best for fresh eating, but does it also have resistance to disease and cracking?

Our all around favorite tomato is the “Japanese Pink.” The Japanese value great tasting food, but have added disease resistance and crack resistance to a very great tasting tomato. It appears pink because it has a thin clear skin, unlike American bred tomatoes with their thick orange-red skin. We also like color, so we’ve thrown in some yellow-red striped German, a gold tomato, a few green and red striped zebra, and a black for a beautiful tomato plate. Tomatoes are self-pollinating, so it is fairly easy to save seed. Family and regional heirloom varieties abound the world over. Although good seed saving involves fermenting the pulp and the seeds to kill seed borne diseases, we also hot water treat seeds to kill disease just before we plant.
The optimal storage temperature for tomatoes is about 50-55°F. If stored in a cold environment (34-38°F), they will get soft and lose flavor if stored for longer than a couple of days. We often pick tomatoes a little on the green side so you have a longer window of opportunity to enjoy them, before they over ripen. Tomatoes will ripen on your counter, but when they are ripe, either eat them or store them in a cool pantry or the warmest part of your refrigerator.

Sadly, our early crop of tomatoes was flooded after mulching, pruning and staking. Only a few survived. Our friends at Driftless Organics are supplementing our tomato harvest until our beautiful late crop ripens – or will it? Where is global warming when you need it?

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