What Is The Difference Between The Two?
The two get requested together constantly, yet they achieve opposite results. Thinning takes out a share of the finer branches right across the crown, letting light through while leaving the outline exactly as it was.
Reduction cuts back the longest limbs, making the tree physically smaller without opening it up at all. Describe the problem and we will say which of the two applies.
When Should A Crown Be Thinned?
Choose thinning where a yard has gone dark or the lawn beneath a tree has given up. Carried out correctly, nobody passing on the street would notice anything had been done.
Should the tree return with its interior emptied and a pom-pom of growth on every branch end, something else has happened. The weight has been pushed outward, which leaves each limb likelier to snap.
When Should A Canopy Be Reduced?
Reduction suits a tree that has outgrown where it stands, or one whose long limbs are asking too much of a shallow root plate.
Weight comes off with either treatment, though only reduction shortens the lever arm itself. Where roots have no depth to work with, that makes reduction the more valuable of the pair.
Does This Work Make A Tree Safe?
Risk falls with both, and a lighter crown really does put less demand on the roots. The money is well spent.
What neither can do is undo rot at the foot of a trunk or reseat roots that have already travelled. Faced with either of those, crown work is beside the point, and we will tell you as much.
Why Will You Not Top A Tree?
Topping is the practice of sawing main limbs back to bare stubs, ignoring where the next branch happens to sit. It is still sold locally as a safety measure, and the effect is the reverse.
What the tree throws out afterwards is a thicket of shoots rooted in nothing but wound tissue. Five years on the crown weighs more and holds together worse, sitting on stubs that are quietly rotting. No price makes this available from us.
How Much Can Safely Be Removed?
Past a certain share of the crown, an older tree simply cannot replace what has gone. Roots sitting in wet clay have less oxygen and less in reserve, which pushes that ceiling below the published figures.
For that reason the quote names a conservative maximum. Wanting a considerably smaller tree leaves two straight answers: stage the reduction across several seasons, or take it out and plant something that fits.