Topping growth versus Natural growth (Pictures)

[sean_freeman]

Great post Guy, Scott I think you are quite right Alex would have really liked the fact that we are still working hard to understand just what the correct 'dose' is for any particular tree in its particular circumstances.

Topping does much more than just remove photosynthetic capacity as most are aware it produces massive disruption to the hormonal growth control system that had been established in the untopped tree - and for many species the resultant multiple shoots emerging from around and below those cuts (if left untouched) will continue to cause both functional and structural problems for the tree.

Retrenchment or regenerative pruning is an attempt to further refine just what we understand and expect from our pruning dose...as much about where we make the cuts what cycle of return work we are trying to impose as it is about the % of live material being removed (and yes of course it is about the % too!)

 

[guymayor]

Thanks Scott! I think the 'adaptive growth' you speak of are reiterations, new upright branches. And yes we do well to follow Nature's lead.

The 60% cut-to-upright-lateral advice is in Harris p. 364.

IME the lower and inner upright laterals are good to leave, IF they get sun. Pruning the downrights from above is often needed (and desired anyway for aesthetics aka thinning cuts).

Sean yes the % belongs later down the list of specs. The frequency of return visits needed is often quite exaggerated. Many times only 1 visit essential, 5-10 years later, to correct codoms....o and btw have you found news of that vet in oz yet?