Tomatoes grow best when the nighttime temperatures are above 60 degrees and daytime temperatures are between 70 to 90 degrees. They take between 52 and 85 days to mature. Tomatoes can be grown as far north as hardiness zone 3 (the coldest in the continental United States) if the right variety is chosen, according to the University of Montana. Choose tomatoes based on your personal preference of taste and color, and your USDA hardiness zone.
Indeterminate and Determinate
Tomatoes are a frost-tender perennial grown in most gardens as an annual. Indeterminate tomatoes have blossoms, immature fruit and ripe fruit all at the same. They produce a steady harvest all season long. The plants keep growing until frost. Staking the tomatoes or caging keeps the fruit off the ground. Weather above 90 degrees F halts fruit production. Cut back indeterminate tomatoes after that summer heat and they will most likely reward you with autumn tomatoes.
Determinate tomatoes ripen all within a short time period, usually within two to three weeks according to the Cornell University. The plant benefits from staking or being in a tomato cage when it's heavy with fruit. The plant is not as vigorous a grower as indeterminate. When the vine starts to set fruit, it stops growing.
Tomatoes vary in size from tiny raspberry size to giants over 2 lbs. heavy. The smaller sizes are clustered together. Micro Tom has 1/2-inch fruit and is the smallest variety of tomatoes according to tomatogrowers.com The size of a tomato can be increased within certain limits by removing other tomatoes so the vine focuses on the ones that are left. If a tomato is bred to be small to medium size, it's difficult to get it to be giant sized. Supersteak, Delicious and Beefmaster are all over 1 lb. each.
Tomatoes come in various shapes and sizes. The most common is round. Pear-shaped are usually small about the size of quarter. Grape is the size and shape of its namesake. Some round shapes are also deeply ridged at the top. The Roma tomato is an example of an egg shaped tomato. Tomatoes may also be somewhat flattened.
Most tomatoes are the typical "tomato red" color most people associate with the fruit. Even if the tomato is bred to be a different color, the taste is still sweet and tangy with a bit of an acid bite. Some tomatoes are sweeter than others; but that depends on the sugar content, not the color. Yellow tomatoes include Mountain Gold and Lemon Boy. White Wonder is a creamy white. Evergreen stays green even when ripe. Pink Girl and brandywine are pink tomato varieties.