I agree with Tim’s approach if you have the mulch available (I use arborist woodchips, spreading about 14yds this week). The chopping might help in how it slight pulls at the roots, loosening the soil underneath like an herbivore can when grazing, but I think it’s not necessarily worth the effort if smothering with deep mulch.
The main benefits of chop and drop in my opinion are:
- retention of as much organic matter as possible
- a proportional amount of the root system dies back, effectively injecting compost into the soil with minimal disturbance and oxidation/nutrient loss
- protecting the soil and its ecosystem. If we think about a habitat as food-water-shelter-space, debris/mulch of chopped and dropped plants provides all these requirements for diverse organisms and the succession of the soil ecosystem
- the relatively stable habitat within the mulch (temperature and moisture are moderated greatly) allows for this ecosystem succession from bacterial Ky dominated and less diverse dirt towards fungally dominated (fungal species increase exponentially over time without disturbance, but bacteria also diversify just do so with a more linear increase over time).
- this succession is where disease and pest resistance comes from. The decomposition cycle is a little microcosm of evolution, with abundant species of pests or disease being consumed by their predators or control species. If we just leave well enough alone and have enough diversity around us in healthy ecosystems, we will inevitably see natural controls for our plant problems.
Success with succession!