Planting Early Tomatoes - April 21, 2010
Jeff Schalau, Associate Agent, Agriculture & Natural Resources
University of Arizona Cooperative Extension, Yavapai County

Tomatoes are the most popular garden vegetable crop in the United States. They grow and produce well in the Verde Valley area and can be grown using a variety of methods. The basic requirements are: six hours or more of sunlight; deep, well-drained soil; a water source; and a fence or other barrier to keep out hungry wildlife. If you want to get your tomatoes in the ground now, you will also need some sort of frost protection.

Purchasing quality tomato seedlings is not as easy as you might think. Most backyard gardeners like to grow indeterminate heirloom varieties because of their flavor and the ability to save seeds. Indeterminate varieties continue to grow through the entire growing season producing flowers until they are killed by fall frost. The harvest from indeterminate varieties often extends over 2 or 3 months. Yields are generally heavier than determinate types, but are later to mature. Determinate tomatoes grow to a certain height and then produce flowers and fruit.

If you donít grow your own tomato plants from seed, then you are often limited to the varieties available at commercial nurseries. There are hundreds if not thousands of tomato varieties. If possible, buy them at a Farmerís Market or from small local growers. The tomato transplant should not be root bound, but you should see some white roots on the outside of the root ball. Plants having three or four true leaves are ideal for planting and the biggest plant is not always the best when looking at tomato transplants.

Tomatoes are warm season vegetables. If you plant before the danger of frost is past, you must use a method of frost protection. My favorite for tomatoes is the Wall OíWater (WOW). These transparent plastic devices are about $3 each and consist of vertical sleeves that hold water and protect plant from frost damage. The water absorbs heat during the day and reradiates it at night. The WOW also protects the tomato plant from drafts.

Before working the soil, make sure that it is not wet. It should crumble between your fingers. Add a generous dose of compost (hopefully homemade) and a small amount of nitrogen fertilizer. Excessive nitrogen results in lots of foliage a limited fruit. If you have soils developed from limestone, add a small amount of soil sulfur too. Spade this in to a depth of one foot and mix it well. Then, I remove a shovel full of soil and place a small amount of triple super phosphate (0-45-0) at a depth about 3 inches below the where the root ball will be planted. Phosphorus is not mobile in the soil, so placing it below the root zone maximizes its availability. Bone meal and rock phosphate also contain phosphorus, but these products are not as readily available to the plants.

After the soil is prepared, itís time to plant. Plant the transplant slightly deeper than it had been growing in the container. Pinch off the bottom leaves of tall, spindly transplants and lay them sideways in a trench. Carefully bend the stem upward so that the upper few inches of stem are above the soil surface. Roots will develop all along the buried stem. Pack the soil loosely around the plant. Water the tomato plants slowly and deeply to get them off to a good start. Place the WOW over the plant and gently fill it with water. Some people use a five gallon bucket with the bottom cut out to support the WOW while filling it.

Once the danger of frost is past, remove the WOWs and store them so they will not get damaged. At this point, you can stake or cage your tomatoes to better utilize the vertical space in your garden. Indeterminate tomato plants should also be pruned to remove the suckers (side shoots) growing from each leaf axil. Many people leave one or two suckers depending on available space. Pruning results in healthier more productive vines.

Naming of companies or products is neither meant to imply endorsement nor criticism of similar companies or products not mentioned.

The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site:

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Arizona Cooperative Extension
Yavapai County
840 Rodeo Dr. #C
Prescott, AZ 86305
(928) 445-6590
Last Updated: June 21, 2010
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