What is the focus of 'heading back' in pruning practices?

The focus of 'heading back' in pruning practices involves trimming twigs or branches back to an axillary bud or node. This technique encourages the plant to produce new growth from the remaining buds, which can lead to a denser and more bushy appearance. By cutting back to these specific points, the plant is stimulated to create new shoots that grow outwards, rather than elongating the existing branches.

This practice is particularly beneficial in shaping plants and controlling their size, as it helps maintain a desirable form while promoting healthy growth. It can also enhance flowering in some species by encouraging more lateral growth, which can lead to an increase in the number of flowering sites.

The other options do not align with the concept of 'heading back.' Eliminating entire plants does not address the selective nature of pruning, while removing foliage to enhance photosynthesis pertains more to maintaining leaf health rather than branch heights or structure. Cutting roots to improve soil aeration falls outside of the scope of pruning entirely, focusing instead on root management and soil health.