Gallery

How to make a girdling tool from an ordinary flatware butter knife

1) Morrion Berg, Field Staff at the UW-Arboretum with an ordinary flatware butter knife, soon to be a girdling tool for small diameter aspen stems.

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2) Morrion uses a grinder

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3) and emery wheel to make the butter knife tool. The UW Arboretum shop is the site of the creation of many different tools for accomplishing field work. As Morrion says, "You gotta have the right tool for the job."

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4) I insert the knife into a vise grip

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5) and then use a grinder to cut off the end of the butter knife

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6) in order to end up with a blade about 1.5" long. (You may want to adjust this after you have used the tool and find you like a longer or shorter cutting edge.)

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7) Once the blade is cut I use the emery wheel to flatten and sharpen both the newly cut edge

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8) and the blade edge of the butter knife so I have two cutting surfaces at right angles to each other.

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9) I am especially careful about removing the sharp corner from the outside edge, which can put a hole in your gloves (or your hand).

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10) Once I have the two edges sharpened I put the blade back in the vise (blade end down) and bend it toward myself

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11) just enough to put a curve in the blade.

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12) This curve really helps in the cutting around the young aspen trees.

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13) A critical aspect of this tool is that it won't close on you like a pocket knife. We made ourselves a larger version of this cutting tool out of an old automobile spring for girdling bigger trees. For aspen we need something small to go after all the small diameter stems coming up, although the tool will easily work on trees up to 4 inches in diameter. You need to girdle the stems when the sap is flowing and the phloem and xylem are not adhering to one another. In south-central Wisconsin this is between mid-April and mid-August. You find the lowest dormant bud otherwise the tree will just send a new sprout sideways below your cut. Insert the knife using the sharpened end blade to slice into the bark

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14) and then slide the knife into the cut.

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15) Work your way around the sapling

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16) Here's another shot.

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17) until you can peel away the bark from around the entire stem

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