Green Horizons

Missouri Walnut CouncilThousands of farmers in Missouri own tens of thousands of acres of woods along creeks. The vast majority of these tracts are now unmanaged and forgotten. But, there is generally something in those woods that justifies attention. Black walnut trees generally thrive on these deep alluvial soils and can become a valuable crop, especially if their growth and sales are managed.

These forgotten parcels of land have resulted from two changes in farming practices.

Decades ago, the small irregular fields along the creeks were intensely farmed because these areas had some of the most productive soils for row crops that were planted with 2, 4, and 6-row equipment. Today, the large operators use 16, 24, or 32-row planters (up to 80 feet wide) that can not physically or economically operate in these small fields. These little fields have been idled and forgotten.

Secondly, as small general farms have been consolidated into large operations, many no longer have livestock at all or the livestock have been excluded from the creek areas.

The neglected parcels have transformed into a mixture of invasive weeds and brush that insidiously becomes a tangled mess of vines growing on a mixture of hardwood species. It’s a shame because there are generally only a few nice walnut stems that develop without some help. With just a little care during the formative period of the succession, the density and quality of the walnut growing on these ideal soils can be much greater and be financially rewarding.

Several large, naturally growing walnut trees that have been ‘found’ in the lower left-hand woods today were no doubt some of the very same trees that can be seen as scattered trees growing in the pasture back in 1956.

A pocket tree identification guide and a little management can directly affect both the amount and quality of highvalue walnut, oak and cherry that might be growing in your forgotten woods. Once you have identified your high-value trees, the next step is to encourage their growth.

Like weeding your garden to promote the growth of your best vegetable plants, you will want to remove trees that are competing with your high-value crop trees. If the trees you are removing are small (less than five inches in diameter as measured at your waist) simply cut them off with a small chainsaw. To prevent sprouting, treat the outer ring of the cut surface with a labelled herbicide. No need to bend over; just cut them off at waist height. This way you won’t twist an ankle or puncture a truck tire. Within a few years the treated tree will rot off at the base.

Larger trees can be ‘girdled’ with that same small chainsaw. Your goal is to cut a continuous ring about one inch deep into the wood all the way around the tree trunk. Make sure that the ends of the cut connect or you may not kill the tree. As with the smaller trees, treat the girdle by applying a few squirts of a herbicide in the cut to prevent sprouting. The dead tree will safely come down a limb at a time, so that when the main trunk falls it will not damage any crop trees.

Lastly, kill grape vines! While they might have a place in some locations of your woods for wildlife food and cover, they have NO place growing in the canopy of your crop tree. Uncontrolled vines will kill your crop tree by shading out its leaves, create "sails" that can catch wind or, worse, ice, and once it does die prevent it from falling safely to the ground.

More than 150 people gathered to hear this topic at this year’s National Walnut Council meeting. If you are interested in learning more about managing black walnut and other fine hardwoods, visit the National Walnut Council’s Web site www.walnutcouncil.org or contact Harlan Palm with the Missouri Chapter at palmh@missouri.edu or (573) 882-1402.