Tomatoes are already one of American’s favorite vegetables, but with the renewed interest in homegrown food, their popularity is growing through the "green" roof.

Considered a warm-season crop because plants need warm soil and frost-free nights, tomatoes are best planted outdoors after mid-May in the Chicago area. Even then you might need to cover plants, which is why many gardeners wait until after Memorial Day to plant.

Choosing the Best
The best tomato varieties to grow depend on where you live. Our midwestern growing season is pretty short, so it’s important to know how many days a particular variety needs to produce ripened fruit. A variety needing 55 days will reward your efforts sooner than one needing 85 days or more.

There are two different types of tomatoes. Determinate tomatoes produce one crop on shorter, bushier plants that typically don’t need staking. Indeterminate plants continue to grow and produce new flowers and fruits, with vines up to 20 feet long that need some kind of support unless you have space for them to sprawl.

Many cooks and gardeners appreciate heirloom tomatoes—the old-fashioned varieties our ancestors grew, which have been rediscovered for their taste and long growing season.

Keeping Them Happy
Tomatoes need full sun and organically rich soil that stays evenly moist yet drains well and is rarely soggy. Make sure plants get 1 inch of water a week, more if the weather is especially hot or windy. A 2- to 3-inch layer of organic mulch will conserve soil moisture and keep soil evenly moist, helping to prevent some common tomato problems.

Knowing how many plants to grow depends on how you will use them and how much space you have. If you preserve or oven-dry tomatoes, and your family and friends will feast on fresh tomatoes throughout the season, six plants is a pretty good number to start with.

Transplants should be spaced 1 foot apart if they will be supported, and 3 to 4 feet apart if there is room for them to sprawl. Dwarf varieties are easily grown in containers, making them a favorite crop of urban and small-space gardeners.

Tomatoes growing in organically rich soil need less supplemental fertilizer than plants growing in soil with an organic content of less than three percent, as measured by a commercial soil test. Because tomatoes are heavy feeders, they need a midsummer boost of organic fertilizer when plants begin to flower and set fruit. Give container-grown tomatoes light but frequent applications of liquid fertilizer.

Future Plantings
Along with eggplants, peppers, and potatoes, tomatoes are members of the Solanaceae family. Crops in this family must be rotated to avoid depleting soil or inviting pest and disease problems. Allow at least two, and ideally three years or more, between the times you plant them in the same place.

Not Your Mother's Tomatoes
There was a time when tomatoes came in just one color. While most gardeners still have room for the classic reds, there are delicious varieties producing tomatoes in shades of yellow, pink, black, and even striped.

Here are some varieties of tomato (Lycopersicon esculentum) that you may enjoy growing in your home garden:

• L. e. 'Beam's Yellow Pear' – Abundant 1½ inch pear tomatoes with great taste. Ideal for salads. Indeterminate. Heirloom. 70-80 days.
• L. e. 'Black Cherry' – The sweet and tasty fruits are black in color. 4 â€“ 8 inches. Indeterminate. Heirloom. 65 days.
• L. e. 'Brandywine' – Rich-flavored, succulent, deep pink fruits. Indeterminate. 85 days.
• L. e. 'Cherokee Purple' – A large heirloom with dark purple fruit, it is said to have come from Cherokee peoples. Indeterminate. 85 days.
• L. e. 'Gold Medal' – Large, yellow fruit with a hint of blush in the center. This full-sized heirloom tomato can weigh between one and two pounds. 75 days.
• L. e. 'Juliet' – Glossy red oblong fruits are produced in grapelike clusters on this All-America Selections winner. The crack-resistant fruit holds well on the vine. Indeterminate. 60 days.
• L. e. 'Mortgage Lifter' – Produces large (two pounds and more), mildly flavorful, reddish pink fruit that is very meaty and contains few seeds. Indeterminate. 80 days.
• L. e. 'Mr. Stripey' – Interesting medium-large beefsteak-style, heirloom tomato bearing red fruits with orange/yellow stripes. Fruits can weigh up to a pound and have good flavor. 70 â€“ 80 days.
• L. e. 'Opalka' – An heirloom tomato that produces numerous 6-inch-long by 3-inch-wide red tomatoes. Sweet in flavor. Grows in clusters of three to five fruits, holds well on vine, and has very few seeds. A great paste tomato. 85 days.
• L. e. 'Pineapple' – A very large heirloom with bicolored yellow and red fruit. Streaked on the inside and outside, the fruit has a wonderful, rich, sweet flavor. Strong vines bear an abundant crop. Indeterminate. 85 days.
• L. e. 'Red Robin' – A dwarf variety of cherry tomato for container growing. Ornamental, 8- to 12-inch plant bears masses of sweet, 1¼-inch fruit. 55 days.
• L. e. 'Sunsugar' – Fruits heavily with orange cherry tomatoes. They are crack resistant and very juicy. 62 days.
• L. e. 'Wapsipinicon Peach' – This heirloom produces 2-inch pinkish yellow tomatoes that are fuzzy like a peach. Very flavorful and sweet. An excellent gourmet tomato. 80 days.