What season are tomatoes?
Hereof, do tomato plants survive winter?
Tomatoes are referred to as tender perennials, as they will generally succumb once temperatures drop, especially once frost hits. Other tender perennials include bell peppers and sweet potatoes, which will also die back once frost is in the forecast.
In respect to this, when can I put tomatoes outside?
You don't want to be starting your tomato seeds more than six weeks before nighttime temperatures (either outdoors or in your greenhouse) are reliably above 57 °F (14 °C) although most varieties will tolerate temperatures a little cooler—note emphasis on 'tolerate!'
Yes, you can cut dead leaves off a tomato plant, and this can be especially helpful if you are worried that the leaves might be diseased. Removing dead leaves may help increase the fruit production.