It is best to apply the Fertilome Brush Killer and Stump Killer to a freshly cut stump to get the best results, so it would be good to cut the stump down before using.
Fertilome Brush Killer and Stump Killer can be used at any time unless the temperatures are freezing. If the product is used as intended, the tree should be cut down and applied to the stump to prevent sprouting with a paint brush or sprayer to completely cover the freshly cut surface. Do not reuse the paint brush. Wrap in several layers of newspaper and discard in the trash.
Fertilome Brush Killer and Stump Killer can be used to kill the stump of a magnolia or other tree. Apply the product at full strength to the fresh cut stump. See the product label for complete application instructions.