Killing a Tree Manually
Killing a tree is hard work, particularly if you avoid using chemical assistance. You have to cut off a tree's water, food and/or sunlight at a critical time in it's life cycle to do the job. Herbicides work by gumming up or shutting down a tree's working parts to deprive the plant of one or more of the above.
See: Chemical Weed-tree Control.
Using the Bark
Trees can be killed without herbicides or chemicals but extra time, patience, and understanding of tree anatomy is necessary. You most especially need to know about the function of a tree's inner bark - cambium, xylem and phloem - and how they combine forces to effect a tree's life.
The bark is a tree's most vulnerable body part above ground. Bark is made up of cork and phloem which protects the cambium and xylem. Dead xylem cells carry water and minerals from the roots to the leaves and is considered the tree's wood. Phloem, a living tissue, carries manufactured food (sugars) from the leaves to the roots. The cambium, which is a moist layer only a few cells thick, is the regenerative layer that gives birth to xylem on its inside and phloem to its outside.
