North American Fruit Explorers mailing list at ibiblio

[John Bunker <jbunker@gwi.net>]

on 2/4/04 6:27 PM, Lisa Almarode at lisaalmarode@yahoo.com wrote:

> How far can I separate european plums (or japanese)
> and get pollinization?  Is 100' too far?
> 
> I'm considering using "Coe's Golden Drop" as a yard
> tree, outside but not far from the orchard.  It's
> about 100' from Victoria and Stanly, slightly
> further from the Japanese plums; and there's an
> apple tree and flowers between the two locations.
> 
> Lisa in Ashland Oregon
> USDA zone 7 Sunset zone 7 1800' elevation
> 
Lisa,

Plum pollination is complicated and mysterious and has never been described
with any certainty.  It is a huge subject, in part because some Prunus
species are at least partially if not wholly self-fruitful, while others are
entirely dependent on cross pollination.  Also, Prunus is a rather large
genus and while some of the its species will cross with other species, many
are not compatible. Pollination of the various interspecic hybrids is a
whole different subject.

P. domestica ('European') plums are generally considered to be
self-fruitful.  Your Coe's Golden Drop may not benefit from a second plum
tree at any distance away.  However, some authors suggest that a second P.
domestica variety (such as Stanley) planted somewhere near by could increase
pollination. A hundred feet may be close enough.

P. salicina ('Japanese') plums are generally considered NOT to be
self-fruitful.  In this case, a second variety would be required.  And, a
hundred feet would probably be too far away.  And, P.salicina and
P.domestica are NOT compatible.

Some authors (such as Hedrick, Plums of NY) suggest that plum pollination
may even be variety-dependent.  In other words, two plums of the same
species may or may not cross-pollinate even if the bloom times are
identical.

My suggestion would be to find someone near you who has fruited a Coe's.
Then plant whatever they did for pollination at that distance.  If they only
have a Coe's, then do nothing!  If you are purchasing the tree, I would
suggest that you contact the nursery for information although my guess is
that they will be as confused as everyone else.  If they tell you something
with any certainty, I'd ask them if THEY had fruited it themselves.

Regards,

John Bunker

Attempting to Understand Plums
Plum Interest Group
Palermo ME 04354