How high is too high to tap a tree on lines?

[Swingpure]

Last year, my first year of tapping, I strung my lines at what I thought was a good height, but when I connected my drops, I basically had them straight up. At the time of installing the taps, I was standing in snow, and when I went to remove them after the snow had melted, it was all I could do to reach them.

Reading about the sap pressure in a tree, it is my understanding that the higher you tap on a tree, the lower the sap pressure. (I think there is a better term for it other than sap pressure). I thought perhaps part of the reason I did not get as much sap from each tree as expected, was because I tapped the trees too high up on the trunk.

This year when stringing new lines, I strung them a little lower on the tree trunks and will wrap the drops a little more around the tree to reduce their overall height from the ground.

After doing that, I came across this YouTube Video from CDL on the Precision Tapper. What I noticed watching the video was how high up the trees they were tapping. At times they were tapping even higher than I was last year. (I suspect they were doing that for slope reasons)

https://youtu.be/mJAjaxRkzoQ

This takes me to my question, when tapping with lines, how high is too high to tap on the tree trunk?

[Pdiamond]

I want to point out one thing about that video, you are correct about the slope, and they are also using vacuum to pull sap. I had my first line up last year and had taps in with the highest at about 4.5 feet. This was to create slope. Most of my taps are at waist height or just a little bit higher or lower depending on where last years tap was.

[Z/MAN]

Keep in mind that tapping too low could have your lines buried in snow, especially where you live. Ask me how I know?

[Swingpure]

Keep in mind that tapping too low could have your lines buried in snow, especially where you live. Ask me how I know?

Actually I am a little afraid of that. I will be walking all of my lines at least a couple times a week and may have to help out in a few locations. There are a couple locations where the line spans an area with a ridge, which come tapping time, I may have to remove some snow.

99%+ of my lines, I have nothing to worry about.

So how do you know? Lol

[Z/MAN]

Take it from me. When the sap is flowing the last thing you have time for or want to do is shovel your sap lines out.

[DrTimPerkins]

This takes me to my question, when tapping with lines, how high is too high to tap on the tree trunk?

The loss of head pressure from tapping high is minimal over the range normally used. If you tapped on a ladder, the head pressure might be noticeably less -- otherwise not really. That small amount of loss is probably offset by the fact that sugar content goes up as you move higher on the trunk (closer to the source of sugars -- the leaves). So overall it's mostly a wash, unless again you're tapping on a ladder. If you do that, it's presumably for a different reason than just to tap higher up.

Tapping is normally done from the height of the lateral line upwards to where it is comfortable to reach. Tapping well over your head is problematic for a couple of reasons. First, it is harder to do and far more tiring (heart has to work hard to pump blood up to your muscles when working above your head). Secondly, it is very difficult to make a good taphole when you're reaching high.
bad technique.jpg

This is because the movement of the drill in-out when tapping over your head is hard to accomplish without putting a little arc on it. That up/down movement is what creates oval tapholes or drill bit scoring along the top edge of the taphole.
scoring mark in taphole.jpg

Not such a big deal with gravity sap collection, but under vacuum, and particularly under high vacuum, that is a point where the taphole may leak.

The better approach is to examine the entire tapping band to find the appropriate place to put a taphole (another whole thread), make sure the dropline can reach that spot, take a stable stance and brace your elbow on the tree, place the drill on the chosen spot, then drill in/out in one quick motion with NO sideways or up/down movement imparted on the drill. If you still have a hard time making good tapholes, consider using an Accu-Tapper.
proper tapping technique.jpg

As already mentioned, snow height is an important factor. You do NOT want to be shoveling your lateral lines (or mainlines) out of the snow during the season.

Two other considerations on taphole height. If you're using very good sanitation practices and have very good vacuum, tapping below the lateral is a good option, particularly for trees that have been heavily tapped or are growing slowly (big, old trees). Secondly, for people tapping with buckets, they'll often place the taphole at a convenient height to hang/retrieve a bucket, which falls within a pretty narrow height band. At the same time, bucket tappers tend to approach the tree from the same side all the time (again, due to convenience in picking up the buckets when collecting). This can result in cluster tapping. So even with buckets, be sure you're spreading the taphole around, both up and down and all around the stem.

[BoerBoel]

I have one section of maple trees that are in a cow pasture. In order to not have the cows grab a hold of my drop lines, some of my taps are 8'-9' up. I wish the cows weren't there but it's not my bush/trees/cows/field.

[Swingpure]

The loss of head pressure from tapping high is minimal over the range normally used. If you tapped on a ladder, the head pressure might be noticeably less -- otherwise not really. That small amount of loss is probably offset by the fact that sugar content goes up as you move higher on the trunk (closer to the source of sugars -- the leaves). So overall it's mostly a wash, unless again you're tapping on a ladder. If you do that, it's presumably for a different reason than just to tap higher up.

Tapping is normally done from the height of the lateral line upwards to where it is comfortable to reach. Tapping well over your head is problematic for a couple of reasons. First, it is harder to do and far more tiring (heart has to work hard to pump blood up to your muscles when working above your head). Secondly, it is very difficult to make a good taphole when you're reaching high.
Attachment 22662

This is because the movement of the drill in-out when tapping over your head is hard to accomplish without putting a little arc on it. That up/down movement is what creates oval tapholes or drill bit scoring along the top edge of the taphole.
Attachment 22663

Not such a big deal with gravity sap collection, but under vacuum, and particularly under high vacuum, that is a point where the taphole may leak.

The better approach is to examine the entire tapping band to find the appropriate place to put a taphole (another whole thread), make sure the dropline can reach that spot, take a stable stance and brace your elbow on the tree, place the drill on the chosen spot, then drill in/out in one quick motion with NO sideways or up/down movement imparted on the drill. If you still have a hard time making good tapholes, consider using an Accu-Tapper.
Attachment 22664

As already mentioned, snow height is an important factor. You do NOT want to be shoveling your lateral lines (or mainlines) out of the snow during the season.

Two other considerations on taphole height. If you're using very good sanitation practices and have very good vacuum, tapping below the lateral is a good option, particularly for trees that have been heavily tapped or are growing slowly (big, old trees). Secondly, for people tapping with buckets, they'll often place the taphole at a convenient height to hang/retrieve a bucket, which falls within a pretty narrow height band. At the same time, bucket tappers tend to approach the tree from the same side all the time (again, due to convenience in picking up the buckets when collecting). This can result in cluster tapping. So even with buckets, be sure you're spreading the taphole around, both up and down and all around the stem.

Thank you very much, this answers a number of questions, regarding tapping height and drilling practices. I like that you mentioned bracing your elbow, as last year in my first year of tapping, I found when I braced myself I had my best tapping results.

Thanks again for all of the expert advice and tips you give.

[maple flats]

Too high? Maybe, but some sap is better than no sap. Years ago I had one section where I had trees out beyond the end of my mainline that fell off in elevation. This was before I had vacuum on that section of my woods. I tapped high, even using an extension ladder in order to get the sap and tapping as high as 12-13' off the ground on the lowest trees.
Later I added vacuum on my lines and in that section I lowered the tap height along with changing from 5/16 laterals to 3/16 laterals. The sap flowed quite well while on 26-27" vacuum. Those lower areas were actually pulling sap from below the mainline. I was sold on 3/16 with vacuum.
My tests were not scientific by any stretch of the imagination, but I liked watching the sap flow uphill anywhere from 3' to 7' below the mainline.
I have no flow numbers and Dr Tim will point out that I lost sap potential. My way of thinking was that I was getting decent sap flow at a much lower cost in tubing and fittings than if I'd done it the best way.

[berkshires]

I could be wrong, but it seems to me that whatever pressure is lost in the tree by moving the tap up the trunk will be gained in the tube by that same amount of sap pressure there. This assumes 3/16 lines that keep the sap in them.

Gabe