If the flowers have yet to bloom, wash the earth off the roots and display the whole plant, roots and all. If the plant grows from a bulb, show off the bulb, perhaps in a wide dish of water.

Even in the coldest part of winter, when nothing seems to be growing, there is life if you know where to look. And if you can't find any kind of plant to bring into your home, pile seeds in a dish - clay will look warm - because the kernel holds energy.