Which of the following is NOT typically a method for tree propagation?

Decimal division is not a recognized method for tree propagation. In contrast, seed planting, grafting, and cutting are all well-established techniques used to propagate trees.

Seed planting involves growing new trees from seeds, which can generate genetic diversity and produce offspring that are similar to the parent tree. Grafting is a method where a piece of one plant is joined with another plant so that they grow as a single organism, allowing for the combination of desirable traits. Cutting involves taking a portion of a plant, usually a stem or leaf, and encouraging it to develop roots and grow into a new plant.

In the context of tree propagation, decimal division does not apply as it does not correspond to any horticultural practice. This concept may refer to mathematical terminology rather than any horticultural technique, which further clarifies why it does not belong in this context.