Being outside does a few things for them. For one thing it toughens them up. The biggest thing is that direct sunlight gives them the unfiltered spectrum of light for growth and nourishment. As Tamlin says, even a thin piece of Saran Wrap filters things. Window sills are nice, but a pane of glass takes away even more. It is less ath the best situation and puts that much more stress on the plant. A marginal plant flowering, combines with less than the best growing condition can and has many a plant over the edge - toward death. Basically, indoor conditions put a negative spin on their health.Originally Posted by [b
Keep it outside for as long as possible. Even if you don't live in North Carolina and it gets too cold, people (Wild Bill, for instance) have been successful with mulching their plants to survive the winter. Not that it is necessary to do that, but it is possible.