Walnut trees are a problem tree for landscaping in a yard. The roots, leaves and nuts of a walnut tree exude a toxin known as juglone. Juglone is poisonous to many plants. Because of this, a number of landscaping plants will not grow well beneath a walnut tree. After you remove a walnut tree, juglone will disappear from the surrounding soil within a year.
Stand at least 500 yards from the walnut tree and observe the tree's shape and size. Walnut trees may as tall as 70 feet and as wide as 70 feet in diameter. If the tree grows with a slanted or forked trunk or has an uneven canopy, the tree may topple onto its heavier side. This will help you determine how to best cut the tree down.
Explore the area around the base of the tree as well as the tree's drop zone. Remove any obstacles that could be crushed by the tree when it falls. Clear a path away from the tree so you can retreat as it falls. This will help you to avoid being struck by falling debris or the tree's trunk if it falls or bounces unexpectedly.
Make a cut, known as an undercut, at the base of the tree. Because walnut is a hardwood, you will find it easier to fell the tree with a chain saw than with an axe. The undercut should be in the shape of a wedge or a triangle with a 45- to 90-degree angle and should open in the direction where you want the tree to fall. The undercut should only extend one-third of the way into the trunk of the tree.
Produce a second cut on the opposite side of the undercut. This second cut is known as a back cut. The back cut should be a thin cut located at a point 1 inch higher on the trunk than the tip of the undercut. It should extend two-thirds of the way thorough the trunk of the tree. The tree will begin to tilt in the direction of the undercut. Back away from the tree as it begins to fall. Do not return to the tree's trunk until all debris has settled.
Remove the limbs of a walnut tree by cutting them flush with the trunk of the tree using your chain saw. Stand on the opposite side of the trunk while cutting the limb to avoid having the limb fall on you after it is cut free of the trunk.
Cut the trunk into sections by cutting through it from the top to the bottom if the trunk sits on level ground. If the trunk is tilted into the air, make a cut from the bottom of the wood upward through one-third of the log. Then slice downward from the top side of the wood through two-thirds of the trunk to meet your first cut. This will help prevent trapping the blade with the weight of the log.
Spray the exposed trunk with a liquid systemic herbicide that contains glyphosate. The tree's trunk will pull the glyphosate into the roots of the tree and kill them, which will prevent the roots from producing new tree shoots and will stop the production of juglone. Cut grooves into the remaining trunk with the chain saw to encourage the stump to decay