How to Preserve a Boxwood With Glycerin

Inspect your boxwood shrub and select branches that display abundant foliage. Glycerin can be used to preserve stems of any length, so simply determine what size you'd prefer and remove any suitable branches with a pair of sharp pruning shears.

Place the cut branches on a hard, flat surface. Remove 1 inch of bark at the cut end with a sharp knife and then use a hammer to crush the base of the stem. Continue hammering, moving approximately 4 to 6 inches up the branch. This will help to speed the movement of the glycerin into the tissues of the plant.

Pour one part glycerin and two parts hot water into a bucket, and stir with a wooden spoon or bare branch until the two are well blended.

Insert the boxwood branches into the bucket, submerging the crushed ends in the solution and ensuring all portions of the damaged wood are completely covered by glycerin.

Check the level of the glycerin solution each day and add more as needed. The solution must be at least 6 inches deep at all times for successful preservation.

Inspect the branches regularly. As the glycerin moves through the stems, the leaves will change color. According to the University of Kentucky College of Agriculture, boxwood foliage generally turns golden when preserved in glycerin. When the transformation has reached the tips of the foliage at the top of the branches, the preservation process is complete and the branches may be taken out of the solution. The entire procedure may take two to three weeks, depending on the size of the branches.