I have never noticed. as for the red maples the buds seem to always be there. I pay more attention to the weather than the trees. Although it has been a very cold winter. most of the trees you are tapping are 30-40+ years old and have seen, high waters, heavy rains, extreme cold and extreme heat and maybe a drought here and there. they are very hardy hardy. You have to remember we are are in the southern part of NH and most of the maple syrup comes out of VT and canada where their average cold Temp for winter make us look like beach weather. I wouldn't worry. but get those taps in saps coming soon!!!