The issues with growing tomatoes in Colorado include a short growing season that doesn't allow many varieties to ripen fruit, and dry air and cool nights that prevent the pollination of the flowers of some varieties.

We do not have a home vegetable variety test program at Colorado State University, so we have no research-based information on the performance of new vegetable varieties, including tomatoes. Old standby varieties used in Colorado for some years include 'Early Girl,' 'Celebrity,' any of the "boys" (such as 'Big Boy', 'Better Boy'), and 'Sweet 100' and other cherry tomato types. Information on days to harvest is readily available so you can choose ones for a short growing season (80 days or less types).

Colorado is not known as "tomato country," and good crops along the Front Range are seen in only one or two years out of five. In summers that are uncomfortably warm for people (warm nights), tomatoes prosper. Tomatoes are not an outdoor crop in Colorado's mountains due to the very short growing seasons and are successful at higher altitudes only in cold frames, hot frames, greenhouses, solariums or other indoor situations.