Rootstocks & Vigor
Illustrative scenario • Not a growth forecast
Apple Tree Height Scenario Calculator
Explore a transparent apple-height scenario using a local full-size reference, a planning fraction and a vigor assumption.
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How this tool works
Midpoint = local reference height × selected fraction × vigor assumption. The displayed ±15% band is an illustrative sensitivity range, not a statistical confidence interval. Rootstock vigor is not necessarily the same percentage as tree height.
Assumptions & Physical Constraints:
No universal rootstock-to-height conversion is established here. Obtain a mature reference from comparable local trees and use actual spacing/training recommendations for the named clone.
Scenario: 25 ft × 0.38 × 1.0 = 9.5 ft midpoint; the illustrative ±15% band is 8.1–10.9 ft. It is not a promise that an M.9 tree will reach that size.
Found a questionable result?
Report the inputs and expected result. Calculator feedback is reviewed against the cited rule set.
Frequently Asked Questions
Can pruning keep an MM.111 tree under 8 feet?
While possible through aggressive summer pruning, forcing a vigorous semi-standard rootstock into a dwarf space causes excessive vegetative watersprout growth and reduced fruit yield.