Tropical plants like lemon trees, orange trees, oleander etc. bring exotic flair to your house, all year round. For your glass house, surround yourself with plants that come to full bloom just when the vegetation outside is taking a break, and enjoy summer in the midst of winter.
See your geraniums blossom as early as March. In early spring, from February to April, profit from the first warming rays of sunshine, without heating, and in October or November, catch the last rays to strengthen you for the months of winter.