Tapping height

[afretired]

The way I need to run my mainline is down through a draw, then make a 90 degree turn heading down through the hollow. But where the turn or 90 is, also is kind of a low swag. In that area the taps will need to be fairly high on the trees to maintain a constant slope on the mainline from the beginning to the end. How high is too high to tap a tree? Is 8-10 ft on a 12 inch tree to high?

Dave

[Thompson's Tree Farm]

How long are your legs?:lol: Height will only have a minimal effect on sap flow but the convenience of tapping and pulling spouts may be a factor. You mentioned "maintain a constant slope". As long as a slope is maintained, perhaps you could alter the slope somewhat to alleviate the problem. Just don't go from extremely steep to extremely flat as the turbulence caused will be a problem.

[afretired]

The legs would be a maximum of 100 ft with most falling in under 50ft. I guess I used the wrong term, "constant", Like you said it is actually just slope. If I had vacuum a sap ladder would be great, maybe next year.

Dave

[WESTVIRGINIAMAPLER]

I have quite a few taps I tap off of a ladder and some are at least 10' off of the ground or maybe a little more to ensure proper slope on my lines.

[collinsmapleman2012]

its not too high but at that height you wont get much sap until later in the season. we tried an experiment at our school this year with 5 trees. 2 buckets on each tree one is almost on the ground the other was 10 feet off the ground. the higher one didnt give sap until mid march, and it was tapped mid february

[DrTimPerkins]

How high is too high to tap a tree? Is 8-10 ft on a 12 inch tree to high?

Beyond the convenience factor already mentioned, the answer is....it depends upon whether you're using gravity or vacuum. The design constraints of a tubing system may dictate that you tap this high at some points. Snow depth is another factor that may cause you to tap high some years.

The flow regimes under gravity and vacuum are somewhat different. Think of a tree as a big pipe with the inside full of a sponge saturated with water (sap). If you stand the pipe up, and drill a taphole, the sap will come out (gravity pulls it down). If you put in another slightly lower down, you'll get a little more sap. Of course this all presumes that you're using a wide enough tapping band that you haven't reduced sap flow through the tree base through too much internal staining caused by overtapping over several years.

On vacuum it is less important to tap low because vacuum will move sap a considerable distance up (or down) and also somewhat side-to-side (also meaning you need somewhat fewer taps per tree with vacuum). 1" vacuum Hg = ~ 1 ft water. So with vacuum, you're "tapping" into a somewhat larger reservoir of the stem than you do with gravity alone.

Despite this, it is not good practice to tap so low that your drop lines or lateral lines run uphill. This creates a pocket of stagnant sap that will be a breeding ground for microrganisms. And anticipating the question that some will ask....will a check-valve spout prevent this....yes, to some degree it will, but because the pressure differential is so small at times under these circumstances, it will not always work well, so there may be (at times) some low amount of very slow seepage back into the tree.

[maple flats]

I have one latteral near the end of one mailine where the last tap is at about 13' off the ground. That line has 7 taps ranging from 7' to 13' high and the line shows decent flow. I however, never measured it. The problem is if you need snowshoes during tapping. When that happens, I need to remove the snowshoes to climb the ext. ladder, not very fast tapping that way. However, that is always my last section being tapped. When doing that latteral I take both a 6' step ladder and 16' ext ladder. The last 2 trees need the longer ladder. I have several other latteralson that mainline tht only need the step ladder. This certainly is not ideal but you do what you have to if the addiction is too great to stop.
This section will be gravity for another 2-3 seasons. My better woods start getting vac this year. After this section gets vac you can bet there will be no ext ladders but rather sap ladders. As Dr Tim says, I am sure the flow is less doing it this way but I do get good flow on good days based on watching the flow in the latteral where it dumps into the mainline.