Yard and Garden: Growing Tomatoes

April 11, 2018, 4:09 pm | Richard Jauron, Willy Klein

AMES, Iowa — Tomatoes, available in a variety of sizes, shapes and colors, are the most popular vegetable in the home garden. Gardeners may select bite-sized cherry tomatoes or giant beefsteak varieties ranging in color from red to yellow, orange and pink. Iowa State University Extension and Outreach horticulturists offer tips on suitable locations, good varieties and proper planting of tomatoes. 

cherry tomato plant.In regards to tomatoes, what is meant by the terms determinate and indeterminate?  

Determinate and indeterminate refer to the tomato plant’s growth habit.  

Determinate tomatoes are small, compact plants that grow to a certain height, then flower and set all their fruit within a short time frame. The harvest period for determinate tomatoes is generally four to six weeks, making them good choices for canning as well as fresh consumption.  

Indeterminate tomatoes continue to grow, flower and set fruit until killed by the first fall frost. The fruit on indeterminate cultivars usually mature later than determinate tomatoes but the harvest period often extends over two to three months. Yields are generally higher than determinate types. Indeterminate tomatoes are tall, sprawling plants that often perform best when supported by stakes or cages.  

What are some good tomato varieties for the home garden?  

Suggested tomato cultivars for Iowa include ‘Better Boy’ (indeterminate; red, round, medium-size fruit), ‘Brandywine’ (indeterminate; pinkish red, oblate, large fruit), ‘Celebrity’ (determinate; red, oblate, medium to large fruit), ‘Chef’s Choice Orange’ (indeterminate; orange, round, large fruit), ‘Cherokee Purple’ (indeterminate; rose purple, oblate, large fruit), ‘Early Girl’ (determinate; red, oblate, medium-size fruit), ‘Jet Star’ (indeterminate; red, oblate, medium to large fruit), ‘Juliet’ (indeterminate; red, elongated, small fruit), ‘Pony Express’ (determinate; red, blocky pear-shaped, medium-size fruit), ‘Red Deuce’ (determinate; red, globe-shaped, large fruit), ‘Roma VF’ (determinate; red, pear-shaped, medium-size fruit) and ‘Supersweet 100’ (indeterminate; red, round, cherry-size fruit).  

When can I plant tomatoes in Iowa?  

Transplant tomatoes into the garden after the danger of frost is past. In central Iowa, May 10 is the suggested planting date. Gardeners in southern Iowa can plant one week earlier, while those in northern counties should wait an extra week. In order to obtain good yields, the last practical planting date for tomatoes is June 20.  

What is a suitable planting site for tomatoes?  

Tomatoes perform best in deep, loamy, well-drained soils. Tomatoes prefer a slightly acidic soil with a pH of 6.0 to 6.8, but can be successfully grown in slightly alkaline soils. Tomatoes need at least six hours of direct sun per day for best yields.  

What is the proper spacing when planting tomatoes in the garden?  

Plant spacing depends on the growth habit of the cultivar and the training system used. Indeterminate cultivars that are staked can be planted 1.5 to 2 feet apart within the row. If grown in wire cages, space plants 2 to 3 feet apart. Tomatoes allowed to sprawl over the ground should be spaced 3 to 4 feet apart. Rows should be spaced 4 to 5 feet apart.  

Determinate tomatoes can be planted 1.5 to 2 feet apart in rows that are 4 feet apart. 

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