Yarb Tales - Pruning
May 16, 2016

The Heritage Herb Garden at the Ozark Folk Center graces the park with visual colors and textures, sweet and pungent aromas, and helps us to interpret the history of the human use of plants.

Now, in mid-May, plants are actively growing. Gardeners can stimulate new branching and improve the appearance of specimens through proper pruning techniques. Clean pruning shears and loppers with rubbing alcohol, sharpen the blades and let’s get started.

Imagine how plants grow and move fluid before making a cut. Plants have a vascular system, much like human blood vessels, that transport water and minerals, sugar, growth regulating hormones, and nutrients throughout the entire system. Like our vascular system, fluids move in two directions through different sets of tubes and pipes. These tubes and pipes are bundled together just under the skin or dermal tissue of the roots and stems.

Working upward from the earth, tiny root hairs absorb water and minerals from the growing medium. This fluid moves through the xylem, upwards into larger roots, the crown, into the main stem, the branches, and out into the leaves. When roots are pruned, new feeder roots grow from the tissue that remains with the plant.

Above ground, the leaves of plants are chemical factories. Plants feed themselves and the world by means of photosynthesis (putting together with light). Leaves contain the green pigment, chlorophyll, which produces sugar in the presence of light, carbon dioxide, water and dissolved minerals. These chemicals become plant sap and travel down, through the phloem and are carried to every living tissue throughout the plant to enable growth and reproduction.  

When a stem is properly pruned, the cut is made above a node. A node is the place where leaves or stems occur, which can be seen as a line, knot, bud, or collar and crotch. Potential for new growth takes place at the node, as does the fastest healing. Cuts made between nodes leave a “nub”, which has to die back to a node as it heals. This is unattractive and can allow disease to enter the vascular system of the plant.

When we cut a branch just above the collar that joins it to its parent branch, we are redirecting energy in the form of water, nutrients and hormones to the remaining branch. When we cut stem tips above a node, we are redirecting this energy to the nodes below the cut.

 We harvest herbs to use their desirable flavors and beneficial chemicals. We also prune to remove spent flowers and to control or encourage bushy growth. Deadhead spent flowers before seeds ripen to enjoy a longer period of bloom. When pruning your woody herbs, follow the “take a third” rule and leave the rest of the leaves for the plant. Mints, lemon balm and oregano are harvested by cutting individual stems back to the crown at ground level. Leaves, stems, and roots that lack a healthy color are no longer functioning as a part of the feeding system--these parts should be removed. Pruning is meditative and can be an enjoyable part of gardening.

If I don’t see you in the future—I’ll see you in the pasture.