What causes a tree on a dwarfing rootstock to suddenly start
growing into a full size tree? My dwarf Lapin cherry was
well-behaved for 3 years, putting out new shoots of 6" to 8"
per year, but for some reason this year the new growth is
20" and it's only June!

What causes a tree on a dwarfing rootstock to suddenly start growing into a
full size tree?

I once had a similar experience with a semi-dwarf apple. You inadvertently
allowed the ground level to rise, by mulching or some other process, or buried
the graft too deep. The full-size scion put out roots and the dwarfing stock
disappeared.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

In article ,
Keith Michaels wrote:
What causes a tree on a dwarfing rootstock to suddenly start
growing into a full size tree? My dwarf Lapin cherry was
well-behaved for 3 years, putting out new shoots of 6" to 8"
per year, but for some reason this year the new growth is
20" and it's only June!

IIRC, Lapin is a genetic dwarf -- it's dwarfed on any rootstock.

Having you been fertilizing it? Excess nitrogen can cause excess
new growth. If the tree is in a lawn, it may be getting too much
nitrogen when you fertilize the lawn. Lawn fertilizers are very
high in nitrogen.

In article ,
writes:
| In article ,
| Keith Michaels wrote:
| What causes a tree on a dwarfing rootstock to suddenly start
| growing into a full size tree? My dwarf Lapin cherry was
| well-behaved for 3 years, putting out new shoots of 6" to 8"
| per year, but for some reason this year the new growth is
| 20" and it's only June!
|
| IIRC, Lapin is a genetic dwarf -- it's dwarfed on any rootstock.
|
| Having you been fertilizing it? Excess nitrogen can cause excess
| new growth. If the tree is in a lawn, it may be getting too much
| nitrogen when you fertilize the lawn. Lawn fertilizers are very
| high in nitrogen.


I think this is the problem. It's in a lawn that was fertilized.
I know about preventing scion roots; the graft is 6" above ground..