Rex’s basic tips: How to grow great tomatoes

Photo by Rex Jensen, St.George News

SOUTHERN UTAH – “There’s only two things that money can’t buy, and that’s true love and home grown tomatoes.” So go the words to a song. There is no question home grown tomatoes taste far better than anything you can get in the store. Commercially grown tomatoes are almost all hydroponic, greenhouse grown now and usually picked green and ripened chemically, which makes for beautiful tomatoes, but poor flavor.

Tomatoes will set fruit only if the daytime temperature is below 95 degrees, and the nighttime temperature is above 55 degrees. Outside these temperatures the blossoms drop off. Plant too late, and you won’t get many tomatoes because the daytime temperatures will be 95 or above. Tomatoes can be planted as soon as the danger of frost is gone, but they must be setting fruit in April, May, or June—at the latest. When daytime temperatures soar into the 90s, tomatoes are finished setting fruit.


Tomatoes can be planted now, and as late as April, but not May and June, that is too late. Tomatoes have no frost tolerance, so the nighttime lows must be considered. Gardeners tend to want to plant tomatoes the first warm week of spring, and that’s ok if you understand there could still be some frost. But tomatoes can be covered with plastic, or buckets, or cardboard boxes, whatever you have. If frost is forecast, just cover the plants before you go to bed, coverings can be removed the next morning. The “walls of water” is a more expensive way to protect tomatoes, but they are effective.

Part of Rex's Garden, Toquerville, Utah | Photo by Rex Jensen, St. George News

Remove all blossoms when you plant your tomatoes from the nursery. Staked, or determinate, tomatoes should be planted one to two feet apart. Unstaked, or indeterminate tomatoes, should be planted three feet apart. Tomato plants should be as wide as they are tall when planted. You can accomplish this by setting the plant deep into the soil and leaving only the top portion exposed. All the buried portion of the plant will send out roots.

Consideration should be given to the planting location. In this area, it would be best to have full morning sun with some afternoon shade to mitigate the summer heat. Consider planting tomatoes in an area that can provide protection from wind and direct, late afternoon sun.


Tomatoes can be categorized by maturity class (early, midseason or late), fruit size (cherry, pear, plum or large), plant size (determinate, semi-determinate or indeterminate), fruit color (red, pink yellow or orange), or use (fresh, process or dual use).  Most varieties will grow well in Utah but not all are available.

Common and recommended determinate varieties are: Celebrity, Big Beef, and Floramerica. Excellent and proven indeterminate varieties include: Champion, Fantastic, Early Girl, and Better Boy. Cherry varieties include: Red Pear, Sweet 100s, and Currant Yellow.


Curly tomatoes (diseased) from Res'x garden, Toquerville, Utah | Photo by Rex Jensen, St. George News

Tomatoes don’t need a lot of nitrogen, so a low nitrogen fertilizer is best, I recommend the mono-ammonium phosphate fertilizer (10-50-0) which is water soluble and works well for most garden crops—and it can be distributed through the drip lines. Miracle Gro is also excellent but expensive, and it’s water soluble and can be distributed through the drip system.

Keep all weeds out. Prepare support for the vines. I don’t like cages but prefer using clothesline cord strung between 5 foot steel posts driven into each end of the tomato row. You should have a steel post about every 10 feet or it won’t support the weight of all your tomatoes.  The setup can be seen in the center of this picture. It works well, is inexpensive, and can be reused for years. A strong, healthy tomato plant will produce 8-10 pounds of tomatoes. The main purpose of caging, or support, is to keep the tomatoes off the ground where they will rot or bugs and worms will enter the tomato.

The tomato hornworm will find its way onto your tomatoes. Although pesticides can be applied that will kill these destructive plant eaters, a better way is put on a light glove and pick the worms off by hand, then destroy the worms. If left alone, these worms will strip your tomatoes of all the leaves and eat into the tomatoes too.


The main disease issue in southern Utah is curly top. This is a destructive viral disease carried by the beet leafhopper, and they’re around whether you have beets or not. There is insufficient space to adequately address this topic here, but you can read more on my gardening blog.

In a nutshell, not all gardens or all tomatoes will be infected, but many will be. An infected tomato turns yellow, the leaves curl and have purplish veins. Infected plants stop growing and although the tomatoes will mature, they will get no larger than when they are infected and they will be of poor quality. Infected plants should be pulled and discarded to the landfill.

There is no cure or treatment, so don’t waste time looking for one. Infection is 100 percent fatal, so infected plants should be pulled out of the ground roots and all, and replaced by an uninfected plant. Leafhoppers move into the garden when the growth in the surrounding hills dries up.  This picture above shows an infected tomato plant.

You can find more information on other topics as well at my garden blog.

The Utah State University Extension website is also a great resource.

Dos and don’ts:

  1. Do replenish your soil with humus, compost and manure every year.
  2. Do keep weeds out
  3. Do spend time in your garden
  4. Don’t miss the spring gardening “window”
  5. Don’t crowd plants; thin, you get more with less
  6. Don’t stop learning, as a gardener you must learn how to grow many crops, it’s not easy. When you sit down to a nice meal, thank a farmer who has learned how to grow what you eat…and has successfully battled Mother Nature, disease and insects.

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Copyright 2012 St. George News.

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1 Comment

  • kevinanderson March 21, 2012 at 6:57 am

    I really appreciate the efforts taken to compose these article, i have been growing tomatoes hydroponically for quite some time now and would like to add few points. Many tomatoes are grown hydroponically. a href=”a href=””>advanced nutrients”>Hydroponic tomatoes can taste as good as tomatoes grown in rich soil outdoors. Hydroponic vegetable gardening is fun and easy but there are some factors that influence their growth:-
    Temperature – Tomatoes do best within a range of 55-85 degrees F. Tomato plants can be severely damaged or killed by prolonged cold or even a brief exposure to frost. Tomatoes can handle high temperatures, but are damaged by prolonged temperatures over 93 degrees F.
    Nutrients – Tomatoes need properly-designed nutrients that are easily absorbed, properly balanced, and rich in nitrogen and other components.
    Light – Whether grown indoors or outdoors, tomato plants need exposure to full, strong light for at least five hours each day.
    Pollination – If tomatoes are to bear fruit, they need to be pollinated. Unless growers are going to engage in artificial pollination, the plants must be accessible to pollinators, which can include insects and wind. Obviously, it is difficult to provide pollinator access to plants grown indoors or in greenhouses.
    Overall environmental conditions – Tomato plants suffer when there are windy conditions, extreme heat or cold, polluted air or soils, or presence of insects, blight or disease. Tomatoes need adequate water, but they do not need to be drowned. Avoid overwatering as much as you guard against drought.

    Tomatoes are categorized as either determinate or indeterminate, depending on their growth habit.
    Since indeterminate tomato plants can get extremely large and will keep producing tomatoes all season, they can handle some pruning. If you leave all the suckers to grow, your plants will become heavy and out of control. On the other hand, removing all the suckers will result in a more compact plant, but it will also lessen your tomato yield.
    Determinate type tomatoes don’t really require any pruning at all. Determinate tomatoes tend to be more compact. They reach a certain height and then stop growing. They don’t usually set their fruit until the branches are pretty much fully grown and then they set their fruit all at once.

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