Why not tap large limbs too?

[Galena]

Strictly fwiw....last year I did use a stepladder to tap my two huge red maples because they have burls from approx 3 ft above the ground to almost 6 ft up. So I used the stepladder to tap above the burls, using tubing (check the maple gallery link at the bottom of this post). They did produce some sap but very little compared to the usual workhorses in my lot. Overall I was disappointed, so doubt if I'll bother tapping them again :-/

[Jebediah]

A few times I've clipped off a tiny branch in the spring to see if sap is running--if it is, sap drips out of the end of that branch at a pretty good rate. Have been tempted to try to collect into buckets this way. May be far less than what you get from a regular tap, I realize.

I have a question about tapping guidelines--have these guidelines (taps per tree) been rigorously tested?

[DrTimPerkins]

I have a question about tapping guidelines--have these guidelines (taps per tree) been rigorously tested?

The UVM PMRC is in the middle of a multi-year, multi-faceted review of tapping guidelines. The majority of the work done earlier looked at tapping only from a wounding perspective. We are reexamining that, and also looking at it from a carbohydrate removal standpoint. Then there are lots of trade-offs, how deep to tap, how many taps, species differences, etc. that also need to be factored into the equation. Some of it is also very long-term, so it'll take at least 5 yrs to get a decent answer (and 10 yrs would be far better). We've presented some of this work at different maple conferences, but it'll be several more years before there is a comprehensive guide published.