Yarb Tales - Tree Leaves
October 24, 2016

The Heritage Herb Garden at the Ozark Folk Center graces the park with colors, textures and sweet and pungent aromas. With their natural display, the herbs help us to interpret the history of the human use of plants.

Autumn leaves are falling. We rake and blow them from gutters, lawns and pathways for safety and neat appearances. Leaves are considered refuse by many people. These folks burn them or buy supersized plastic bags in which to send the nuisance waste away. The plastic bags are used once for this purpose and are not  useful to another living organism. Leaves, on the other hand, play important roles in the biological life processes of our home, the Eastern Deciduous Forest.

Leaves are composed of elements, especially carbon, calcium and the major nutrients needed for plant growth known as NPK. According to The Rodale Guide to Composting, oak leaves contain 0.8 % N (nitrogen), 0.35% P (phosphorus) and 0.2 % K (potash).  
After decomposition, leaves release these elements back to the soil which then become available for new plant growth. To break down, leaves need time, moisture, oxygen, nitrogen, soil microorganisms and decomposers such as earthworms, slugs and pill bugs.

Most of the leaves that fall on lawns and thoroughfares at the Ozark Folk Center are gathered and transported to large bins. Sometimes other plant refuse is added, though for the most part, the heaps are built with tree leaves. Every now and then the piles are  turned with a tractor. Eventually the leaves break down into organic matter which is then incorporated into garden soils. This is a slow process.

There is a wire leaf pen near the gardens in the Craft Village that we use for the faster, intensive compost operation. As we fill the pen this time of year, the leaf layers are amended with coffee cans of feather meal, soy bean meal and/or alfalfa meal and sprinkled with finished compost. The meals contain nitrogen that will combine with the carbon in the leaves to speed the decay process. The finished compost  is added in small amounts to inoculate  the leaves with friendly bacteria. These leaves are placed in the bottom of the compost barrel that we use to collect vegetable matter and egg shells from the Skillet Restaurant. In this way the leaves are incorporated into the mix that becomes superb compost the following growing season.

In woodland and other natural areas, autumn leaves are left in place to decompose naturally. Leaves can also be left under large shrubs as mulch and slow release fertilizer.

Perennial Mediterranean natives such as sage, lavender and thyme do not benefit from a covering of tree leaves. The leaves hold moisture and block light and air, creating favorable habitats for fungus that can kill the herbs.

Acorns, hickory nuts and many other seed bearing fruits are falling from trees. After decades of gardening in the Ozarks I have come to the conclusion that it is much easier to pick up these reproductive bodies as they fall into the garden than to uproot the seedlings and saplings in later years.

The future garden will benefit from the natural processes that we utilize to clean up tree refuse during the fall and early winter. If I don’t see you in the future—I’ll see you in the pasture.