Hi, this is my first time trying out tapping trees; wanted to show my kids what it was like. I did it a lot as a teenager and earlier with the family, 200+ trees a year, but that was 20 years ago, so I know I've forgotten all the important bits. Anyway, I have 5 silver maples (Western NY) that I tapped with my boys. 7/16" with metal spiles about 2" into nice yellow wood at a 15 degree upward angle on a day with a high of 45. I've gotten nothing, not even a drop. Now, my property is in an area that has a lot of clay and a high water table, so I'm assuming that isn't helping. Right now it's been below freezing for 4 days so I know that is the current reason, but I cannot figure out why it didn't start good and then taper off. If it was one bad tree I'd chalk it up to bad luck, but 5? Any thoughts would be appreciated!