Tomatoes: a primer

    Tomatoes: a primer

    Davis Enterprise 05/26/05

    What is it?

    The tomato is a fruit (a 'simple berry' in botanical parlance) which is used as a vegetable[1], in fact, it routinely tops surveys as America's favorite vegetable and is right up there with roses as our favorite garden plant. Although the plant is subtropical, and thus perennial in frost-free areas, it is grown as an annual in summer gardens far to the north[2].

     

    Where and how to grow tomatoes?

    Plant in full sun. Amend the soil if you like, but go easy on the fertilizer or you'll get lots of vine and less fruit. Water with your other vegetables until they're a couple of feet high, then water about half as often and at least twice as long--a couple of hours slow soaking is best. Stake or cage them to keep the plants contained and the fruit off the ground. There are safe remedies for the few pest and disease problems you might encounter: ask a garden professional to diagnose the symptoms.

     

    Flavor of tomatoes is somewhat inherent to the variety, but is stronger if they are watered fairly infrequently. The roots go quite deep, and allowing them to dry somewhat between waterings (once established!) will concentrate the flavor in the fruit. This means giving them a deep soaking every 7 - 10 days, and even less often is fine as the season progresses.

     

    Jargon: what are all those funny terms you read on tomato labels?

     

    Some refer to the growth habit, giving a hint as to the size of the plant:

     

    á      Indeterminate means the vine keeps growing and flowering all season. So it gets big! 8'+ is not uncommon, so they need to be staked or caged to keep them from sprawling all over the ground. Yields are very high: fruit continues to set as long as night temperatures are above about 55F, and fruit will ripen until temperatures drop below about 50F. Most tomatoes are indeterminate. Cherry tomatoes in particular are very large plants.

     

    Exceptions: 'semi-determinate' keep growing for a while after they start flowering. Example: Celebrity.  'Dwarf indeterminate' have very short internode distances, so the plants keep growing and flowering all season but stay smaller overall. Examples: Better Bush, Husky Red and Husky Gold.

     

    á      Determinate means the vine mostly stops growing once it has begun flowering. This makes for a more compact plant which will require only a short stake or cage. Yields are lower, but certainly adequate. Production tends to finish up in early fall. Ace is a well-known example. Some are very small plants suitable for growing in pots: Patio, Roma.

     

    Some of the terms refer to disease resistance which has been bred into the varieties.

     

    There are two soil fungi that attack tomato roots, and both occur in this area. Older varieties and heirloom types are not resistant. This can be a concern if you live in a subdivision that was built on old row crop land, such as Mace Ranch, Aspen, or Stonegate.

     

    Plants with a 'V' on the label are resistant to Verticillium Wilt. Plants with an 'F' on the label are resistant to Fusarium Wilt. A couple of years ago, a new strain of Fusarium appeared in tomato growing regions, including Yolo County, so some varieties carry an additional 'F2' designation as being resistant to this disease. Tomato breeders try to stay one step ahead of these new disease variants.

     

    Tomatoes which can tolerate root-knot nematodes have an 'N' designation. Keep in mind that the nematodes will continue to live on the roots and survive from season to season, so it is still important to plant them in a different location each year.

     

    Note: contrary to popular belief, simply planting marigolds with tomatoes will not deter nematodes. A particular group called Signet marigolds will suppress or kill root-knot nematodes when the bed is planted entirely in them--no tomatoes, no other nematode host plants, just Signet marigolds--for an entire season. Nor will marigolds repel or deter aphids or whiteflies, as is often stated by proponents of companion planting. But they do look pretty in the garden, and draw bees, butterflies and other beneficial insects[3]. So there's nothing wrong with planting them!

     

    Some tomatoes are resistant to Tobacco mosaic virus, a disease which can cause stunted and unproductive plants. These will have a 'T' or 'TMV' designation on the label.

     

    Heirloom or hybrid? Gourmet? Low Acid?

     

    á      Heirloom tomatoes are old varieties which have been saved by dedicated growers. Often these are very productive in one region (Nebraska Wedding, Arkansas Traveler), or have some unique characteristic of color, shape, etc., so the seed has been saved from one generation to the next.  Yields are generally lower, and most don't have built-in disease resistance, but they make up for it in character, history, and pedigree.

     

    á      Hybrid tomatoes won't 'come true' from seed because they are F1 hybrids, carefully crossed from separate parents each time; the seedlings will revert to the characteristics of one of the parents, or may otherwise differ if the flower was pollenized by another variety in the garden. If you're going to save the seed of heirloom varieties, you do need to carefully exclude the flower from being pollenized by another variety after you've done the deed: wrap the blossom with cheese cloth or a small paper bag to keep the bees away.

     

    Heirloom varieties are neither better nor worse than hybrids! The varieties that have been saved often have special flavor, are unusually large, or are striped, yellow, orange, white, purple ('black'), or otherwise unique in appearance. Some do very well in blind taste trials, but so do many hybrids. In fact, hybrid cherry tomatoes routinely top taste tests.

    á      'Gourmet' is a term usually applied to imported types, mostly from Italy or France.

    á      'Low acid' refers to varieties with mild, sweet flavor. I've noticed a regional preference for these types from gardeners relocated from the midwest and New England.

     

    So what do you plant?

    How many? A couple of plants will provide you with a summer's worth of fresh fruit. A half dozen will give you plenty to cook and even freeze some. A dozen plants can provide enough for a year's worth of canned or frozen tomatoes.

    Which ones? With hundreds to choose from (my growers have 120+ varieties between them), think about your site, space available, and primary uses. Remember that production will vary from year to year, depending on the weather. Try some new or old varieties each year -- you may find a new family favorite.

     

    á      Limited for space: Ace, Gardener's Delight, Husky Gold, Husky Red, Juliet, Patio, Roma.

    á      Limited sunlight: cherry tomatoes, especially Gardener's Delight, Sungold, Sweet 100 (or newer versions); Yellow Pear, Red Currant are unique and very, very productive.

    á      Reliable production, excellent quality fruit: Early Girl, Celebrity are two I'm never without.  Champion and Better Boy are also reliable heavy producers.

    á      Sauce or salsa: Roma and San Marzano are the classic pear tomatoes; Principe Borghese is outstanding.   Celebrity (productive, thin skin),  Mortgage Lifter (productive, meaty).

    á      Taste test winners: SunGold, a golden cherry type with super rich, sweet flavor, tops taste tests everywhere. Early Girl, Super Sweet 100, Isis Candy, Juliet are other winners. Costoluto Genovese is one of my favorites.

    á      Colorful fruit: Cherokee Purple, Caspian Pink, Lemon Boy, Marval Striped. Yellow Stuffer has hollow fruit! Resembles a bell pepper, great for stuffing.

    á      Varieties to avoid: Beefsteak types don't set fruit above 80 - 85 degrees, which is most of our summer here. Brandywine, a very popular heirloom, isn't on my hit parade due to low yields.

     

    Tomatoes are very easy to grow in this area, with far higher yields and better flavor than in most other parts of the country. Fruit or vegetable, sauce or salsa, and however you say it -- toe-may-toe, toe-mahh-toe, tuh-may-ter -- mid-April to mid-June is a great time to plant 'love apples' in your garden.

    [1] The fruit is used as a vegetable. The Supreme Court ruled in the early 1900's that it was to be considered a vegetable for tax purposes, as at that time imported vegetables were taxed at a lower rate than imported fruits (most tomatoes were imported then). Confused? We eat lots of weird plant parts as vegetables: the artichoke is a flower bud, kohlrabi is an enlarged stem. So the term 'vegetable' really refers to how we eat something, and the narrower term 'leafy vegetable' is used for things used as greens or salads. Other fruits that are used as vegetables include summer squash such as zucchini, and the tomato cousins peppers and eggplants.

     

    [2] Varieties which set fruit under cool conditions, or which ripen quickly, are used in the northern or high elevation areas, though the yield is far less than in California. Note: special cultural practices such as pruning off side shoots ('suckers') are done to hasten the production of ripe fruits in short-season areas and are unnecessary here.

     

    [3] Tomato flowers don't need bees or any other special agents to pollinate them, although bees will certainly visit the flowers. (Technical terms: a 'pollenizer' is another plant which provides pollen. A 'pollinator' is the thing that does the job: a bee, butterfly, person, etc. Easy word trick to remember the difference: 'pollenizers doesn't buzz'). Both male and female parts are present, and the flower simply has to vibrate for them to come in contact, so movement of the plant in the wind is sufficient. Greenhouse growers may need to tickle the flowers. Weird exceptions: Currant tomatoes and their offspring have female flower parts that stick out past the male parts, so they do need pollinators. Don't worry, you'll get plenty of fruit anyway.



    top of page
    Return to Home Page




    © 2004 Don Shor, Redwood Barn Nursery, Inc., 1607 Fifth Street, Davis, Ca 95616
    www.redwoodbarn.com
    Feel free to copy and distribute this article with attribution to this author.
    Click here for Don's other Davis Enterprise articles


    Posted 04/2006 -- page URL: http://www.redwoodbarn.com/DE_tomatoprimer.htm
    Owner of this site: Don Shor (redbarn@davis.com)