The bush we tap has been tapped sense before 1900, and tapped every year to the present except for a 15 year (+ or - ) period when it wasn't tapped. There is plenty of new growth that has come along over the years but we still tap several older trees. We hardly ever see darkened wood when we tap and not sure if i could put a number on what is acceptible. We certanly don't want any, but take what we get. I would rather vote on the least amount as the percentage of darkened wood that we get is a lower than 5%. We plan on producing syrup for many years to come and hope to pass the tradition on to the next generation so we have committed to 1 tap per tree, small taps and a shallow whole deepth. I did not vote on your poll, but would have if it had a less than 5% option.
3rd generation maple producer
3x10 Lightning Small Brothers (on natural gas)with piggyback
Still need more taps, 1100 on vacuum
A 24' x24' sugarhouse (2011)too small(2012)
Homemade Finishing and Bottling Equipment (on natural gas)
Brother to Brother operation with plenty
of family and friends support
Still expanding, new sugar house being planned for 2018