Mountain gardeners lament not being able to grow home-grown tomatoes in particular. I usually recommend that people not struggle with them, but to use their precious garden space to grow things that have a greater likelihood of success (most cool season vegetables like leafy greens and root crops), and simply go buy tomatoes.
If they simply MUST grow their own, there are a couple of different suggestions.
- Gardeners at 7,500' or below might get away with planting the tomatoes right against a south facing wall to take advantage of radiant heat during the night.
- Blossom set sprays help set fruit even with cool nights, and some tomatoes are bred for cooler temperatures, such as the ones from Siberia or the ones bred in Oregon (http://extension.oregonstate.edu/gardening/osu-develops-tomatoes-especially-pnw-gardeners) In general, mountain gardeners will do well to look for determinate, early tomatoes, because even when there is reasonable fruit set, ripening can be an issue (and if you have to finish ripening green tomatoes indoors on your windowsill, the vine-ripened flavor that everyone craves doesn't develop.
- Gardeners at higher elevations may be wise to invest in a greenhouse.
- Another option is to grow what I call a "pet tomato". This is a tomato that you plant in a pot and bring in every night (to allow the fruit to set, and to have the flexibility to continue growing indoors, even when an early frost threatens).