Watch tree buds open up in the house.

Cut twigs about 12 inches long and put them in a jar of water. They will show leaves and or flowers after several days. By bringing these twigs indoors where it is warm, you are just speeding up the natural process that takes place more slowly outdoors. Sketch what you see daily in your Nature Journal.
Try: forsythia, lilac, apple, cherry, dogwood, maple.