We are on what looks like the tail end of our maple season 60 deg forcasts and 32+ degree nights. We decided for fun to tap 25 birch trees today. Most of them are Black birch with a few yellows mixed in. Maple sap ran well once everything thawed out this afternoon but the birch taps are all dry. Does any one know when they would start running and possibly a scientific explaination of what makes a birch tree give sap? This is my forcast for my bush. http://forecast.weather.gov/MapClick...2=-74.6808&e=0 Does anyone know if these are the right conditions? Red maples will bud at any moment and the birch buds look like it is still winter. Thanks.