Sunday, November 22, 2020

[nafex] The heartbreak of grafted pawpaws

I planted my first pawpaws in 2009, I ordered the superior Peterson
pawpaw varieties directly from Neil himself. One of four survived - a
Shenandoah that was vigorous until 2015, then visibly declined. I
removed the dead tree this summer. My working hypothesis was that the
tree suffered a pruning injury back in 2013 or 2014 that became infected
with fungus. That Shenandoah was an outlier, but it is the only grafted
tree that has ever successfully matured fruit for me. It showed me how
delicious selected pawpaws can be.

Every other grafted pawpaw I have planted (about 16 of them) has died
but for two five-year-old (at site) trees that are still less than 16
inches high.

The typical scenario is that the plant will sit for a few years in my
artificially shaded site as it becomes established. Then in its third or
fourth year at site it starts rapid growth. Within a year to three years
of putting on height, it flowers, maybe begins to set fruit (they do not
always get this old) then midsummer, the leaves suddenly wilt and the
tree dies within a few months. Post mortems reveal seemingly healthy
roots, no trunk lesions, no discoloration of cambium.  No clue.

The kicker is that I have healthy seedlings all over the place. Some
seedlings are seven years old, volunteers in the woods where I tossed
overripe fruit. Some were planted intentionally. The rootstock sprouts
well if I leave it and seems healthy. Rootstock has started producing
fruit (not very good fruit). I have divided rootstock from dead grafted
trees to start new patches with the hope of later grafting. I have not
seen remaining rootstock, divided rootstock or seedlings die like the
grafted varieties.

How I care for them:

I water attentively for a couple years after planting, then only when
weather is unusually dry. I shade the young grafted trees for two -
three years at site. I only plant trees in spring. I have tried planting
at ground level and recently higher in mounds to discourage root rot (no
indication of root rot, just varying procedures).

I plant with no amendments in soil, but top with compost around the
site. The trunks are not smothered.

This year, I transferred soil from a native pawpaw patch in the woods to
the struggling small grafted trees in the hope they would get something
they needed. They still are struggling. I will see next year.

Any ideas? Has anyone else dealt with this?

Pawpawless in central NC zone 7a

Elizabeth

--
Elizabeth Hilborn, DVM
Bee Well Mobile Veterinary Services, PLLC
beewellvet.com

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