Standard or mini-standard cable extends to the top of the tree and standard short or long points are attached to the end of the cable and nailed to tree. Larger trees with trunks measuring 3' or more in diameter should have two ground cables extending beyond spread of branches and connecting to proper ground systems.
Ground cables should be buried to a sufficient depth so as not to be misplaced or damaged. In sandy, rocky or very dry soils, an extensive ground system may be necessary. Underground sprinkler systems, water pipes and other metal objects are very good grounds. Standard Conductor No. 32S or Mini Conductor 17S is used on the trunk of the tree; one down conductor for trees with trunks up to 3' in diameter, two down conductors for larger trees.