Plum Pollination. 10.27.15

Among the more challenging aspects of growing Asian and Hybrid plums is pollination.  Some varieties self pollinate, many require a different plum variety.    Different websites have different information.  In different areas, rules that apply in one area might also not apply in another, due to differences in temperature or bloom time.  Sometimes, you just plant a tree or trees and hope for the best.

The nursery sites are not always accurate, or don't necessarily give the wanted information.  The source of the information is not usually given.

Raintree.com - my source for Shiro and Hollywood.  These 2 seem to pollinate each other.  Shiro is described as partially self pollinating, and Hollywood is described as self pollinating.  They bear well in my Vancouver yard, without other visible plum trees in the neighborhood.

Hybrids can indicate any species with another species, but usually refers to Asian species hybridized with native American species.  Asian species give larger size and more meaty flesh, American species add to the flavors and give much better cold compatibility.  Many of the hybrids are about 100 years old, so are nonpantented, and do not have industry or university sponsors or advocates.

University of Minnesota Ag Experiment Station workers did a detailed project regarding hybrid plum pollination  in 1950.   Among their tables, abstracted below.  I summarized only the varieties that I have seen for sale as trees or scion, various sources.

Prunus simonii

From Table 3.   Hybrid and native plums rated as good pollinizers.
Kaga.  P. americana.  12 recipient varieties tested.  Early bloom.
Toka.  P. american X P. simonii.  22 recipients tested.  Early bloom.
South Dakota.  P. americana or P. americana hybrid.  27 recipients tested.  Medium late bloom


From Table 4.  Hybrid and native plums rated as fair pollinizers.
Ember.   P. salicina hybrid X P. americana.  24 recipient varieties tested.  Bloom season, mid.
Hanska.    P. americana X P. simonii.  17 recipients tested.  Early.
Superior.  P. salicina X (P. americana X P. simonii). 18 recipients tested.  Early / mid.
Shiro.  P. salicina hybrid.  1 recipient tested.




From Table 5.  Pollinizers tested and rated as poor.

Prunus salicina "Shiro"

La Crescent.
Pembina.
Underwood,
Waneta.
Tecumsah.

Other comments from the  1950 U Minn paper -

The study began in 1932, and extended for a number of years.

It was noted that native plums had good pollen viability, while hybrids had generally poor pollen viability.   Some had 50% with aborted pollen grains.  Many of the hybrids produced pollen with empty or aborted pollen grains.  Toka was shown to have good viability but a poor pollinizer.  However, in the tables Toka is listed as a fair pollinizer.

Lack of fruit production may be defective pollen, low viability of pollen, or pollen incompatibility.

Among hybrids, more of those with female American plum parent, were good pollinizers. P. simonii may also contribute something to hybrids, in terms of being good pollinizers.

The authors also note that many of the hybrids resemble mainly their female parent.  They go on to say that  this may be due to apomixis, reproduction without sexual fertilization.

So you might think you have a hybrid, based on pollination, when reality the variety is selfed.

Rutland Plumcot.

From Table 8.  Compatibility. Recipient named first, pollen sources follow.  P=poor, F=fair, G=good.

Ember.  Hanska (G), Kaga (F), Superior (G), Toka (G), S. Dakota (G), not self.
Hanska.  Ember (G), Superior (F), Toka (G), not self
La Crescent.  Ember (P), Hanska (P), S. Dakota (G), Toka (G), self not mentioned
S. Dakota.  Ember (F), Hanska (G), Superior (F), Toka (G), not self
Superior.  Ember (P), Hanska (G), Kaga (G), Superior (G), Toka (G), does pollinize self.
Toka.  Kaga (G), Superior (G), not self.
Underwood.  Ember (P), Hanska (F), Kaga (G), Superior (F), Toka (G), self not mentioned.
Waneta.  Ember (G), Hanska (G), Kaga (G), Superior (F), Toka (G), self not mentioned.

This seems to disagree with other reports of Toka pollinizing self.

Finally, there is also an issue of bloom season.

Prunus cerasifera

From Table 8.  Varieties of plums suggested...

Early bloom season - Superior, Toka.
Mid bloom season - Ember, Underwood.
Mid to late - South Dakota.

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Info from TheFarNorthGarden.com website:
"P. salicina hybrids were developed by crossing native wild plums with plum varieties from California that were not hardy, producing hardy trees with good quality fruit. These include 'Pembina' (sometimes called 'Prairie', 'Acme' or 'Elite'), 'Patterson Pride', 'Brookred', 'Geddes' and 'Perfection' (sometimes known as 'Superb'). These hybrids will only produce fruit if they are pollinated by a wild plum, and they do not provide pollination for any type of plum, including each other. This may explain why some growers have poor fruit production with these trees."

Another lesson - plums of the same variety can have different names.

From "Plums on the Prairies" - by Rick Sawatzky, University of Saskatchewan
On terminology - " Pollinators , usually insects, are vectors of pollen movement. Pollinizers are plants which provide the appropriate pollen for other plants"

On Pollinizing - " George F. Chipman who edited the Prairie Gardener for many years and who wrote about plum pollination in 1934. He summarized a study done by Prof. W. H. Alderman at the University of Minnesota by saying, “...very few hybrid plums would accept pollen freely from other hybrids, but they would all accept pollen from native plums”. 

A precaution comes to mind -  not from a specific source, but from my observation - most of these studies and comments regard plums grown in the Midwest, and usually the North Midwest at that.  There, the climate is not friendly to most Asian plums, which is why they are interbred with American species.  Therefore, the pollen from Asian plum varieties might not be tested on the hybrids.  Both Toka and La Crescent have Shiro as a parent, so Shiro might pollinize those varieties.


From LMtreefarm -
Brookgold - Asian plum
Brookred- Asian plum
Greenville  - Asian (Burbank) by P. nigra
Patterson's Pride - P. nigra X Asian plum, 1960
La Crescent - Howard Yellow apricot X Shiro Asian plum 1923
Pembina - Native Canadian plum X Asian plum "Red June"
South Dakota - pollinator for hybrid plums, a selection of Prunus americana.  1949
Tecumseh - Shiro X "Surprise" -
Toka - Native plum X Chinese plumcot P. simonii.  1911.

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Toka plum

HardyFruitTrees states La Crescent is "Also known as 'Crescent', 'Golden La Crescent' and 'Golden Minnesota'. La Crescent is a cross between the 'Shiro' plum (Prunus simonii x Prunus salicina x Prunus cerasifera x Prunus munsoniana) and 'Howard Yellow' plum ( Prunus americana). It was introduced in 1923 by the University of Minnesota Fruit Breeding Farm"

The source has some nice things to say about La Crescent - "sweet and juicy...golden-orange color...flesh is yellow like an apricot... melting and not fibrous... freestone... taste has an hint of apricot. and they note that it is a poor bearer and must be pollinized by and American or Canadian plum.

Of Pemina, they state - "hybrid between a Japanese plum (Prunus salicina) and a Canadian plum (Prunus nigra)... self-sterile... must be pollinated by a wild plum tree, or a pure American plum tree (Prunus americana), or a pure Canadian plum (Prunus nigra)....introduced in 1923 by Niels Ebbesen Hansen from the South Dakota Experimental Station in Brookings"

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Based on all of this information -

-Of readily available varieties to pollinize Hybrid plums, Toka seems to be the best candidate.
-South Dakota seems equally good as a pollinizer, but is harder to find.
-It's not clear to me that Asian plums have been tested as pollinizers for hybrid plums.  It's worth adding them into the mix in this area.
-If a pure American or Canadian plum can be found, those are considered among the best pollinizers for hybrid plums.
-Probably, the more types in the mix, the better the chances for a good crop.  If there is not room for multiple plum trees, or ability to are for multiple plum trees, multigraft is an option.

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Images are public domain via U.S. Department of Agriculture Pomological Watercolor Collection. Rare and Special Collections, National Agricultural Library, Beltsville, MD 20705.  " The majority of the paintings were created between 1894 and 1916."

Puttering in Orchard. 10.28.15

Hollywood Plum Development, 2 years from cutting.  10.27.15

Ember Plum, Hollywood Rootstock.  10.27.15

Vandalay Cherry Flower Buds.  10.27.15

 I traded Ember Plum for Hollywood.  Ember is now in ground, Hollywood in container.  The TLC treated Ember is much larger and more sturdy.  Nice look at the roots for both. 

I still intend to grow a Hollywood Plum tree but can use this one for rootstock, and a larger one in-ground.

Three-year-old sweet cherry trees have promising flower buds.  Next Spring we should get a taste.  They got very little water this year and grew much larger anyway.  Sweet cherries are well adapted to this climate.

Vandalay Cherry Flower Buds.  10.27.15

Home Orchard Plans for 2016. 10.27.15

Raining today. 

Thinking about next year.  Replace some trees that died, and plan for a couple that might, and replace a couple of non-
performers.

Esopus Spitzenburg Apple

Deaths:  
North Star Cherry.  2 years old.  Apparently voles.  There is no bark on the roots.
Big Asian Plum.  From the size and rings, at least 10 years old.  Apparently mining insects.  There were tunnels under the bark.

Non-performers.
Honeycrisp on M27.  Karmijn on M27.  I think this rootstock is way to limiting, and the trees can't grow worth squat.  These are planted near each other, and can be replaced by one larger tree.  I can use the Honeycrisp for scion.
Indian Blood Peach.  Maybe 8 years, only 4 foot tall, no fruit set, ever.

Opportunities.
I have 3 Hollywood Plum trees in containers, and one in-ground, started 2 years ago.  The container trees are larger due to TLC.
I have 1 Ember Plum, 8 foot tall whip, grafted onto Hollywood rootstock early 2015. 
I have potential scion sources, existing Toka plum, Hanska grafted onto on unidentified plum tree, Honeycrisp and Liberty apples on M27.
I have an unidentified plum grown as accidental cutting from the tree that died.  It's a good plum, large, meaty dark purple flesh.

Concerns.
Toka Plum.  Bark on trunk is highly damaged.  I don't know, by what.  I want to preserve the variety.  Use scion from existing tree,  on Hollywood Plum rootstock.

Montmorency Cherry

Plan.  Subject to change at any whim.

1.  Make a new Toka Plum, grafting from existing tree onto Hollywood Plum rootstock. 

2.   Move the unidentified plum cutting to a better location.  Maybe were the North Star Cherry died.

3.  Remove Indian Free Peach.  Replace with Surefire Cherry, new tree.

4.  Remove small Hollywood plum.  That one needs more TLC, transfer to container.  Replace with Ember on Hollywood rootstock.  I can  do that this fall.

5.  Make a Hanska Plum on Hollywood rootstock.  Grow in container to give it TLC until it is a good size.

6.  Buy scion for another plum variety - Superior?  Graft onto the 3rd Hollywood rootstock and give it TLC.

7.  Replace the M27 trees with Nadia Cherry / Plum hybrid.

8.  Try whip / tongue grafting to top work remaining branches of Almaden Duke cherry with Ranier and Lapin sweet cherries.  The T-budding didn't work so well.  A couple might have taken.  This tree has 2 rootstock suckers.  Maybe I should graft onto those, and cut down the original tree.

9.  I have the first apple that I grafted, but mixed the labels.  It is either Sutton's Best or Esopus Spitzenberg.  Either way, I can give that a try.  There is a second graft on that one, again mixed up.  Either Liberty or Jonagold.  I might graft onto that tree, a 3rd and 4th variety.  I can use the Honeycrisp, and might use scion from Fedco for another.

Hanska Plum

10.  I have rootstock, semidwarf but unsure which.  I can graft onto that and keep it in container for TLC.  Options, Pristine, which is early and very good, or something new from Fedco. 

11.  I think I will buy Sweet 16 from Burnt Ridge.   If so, it will need a location. 

12.  Oregon Curl Free Peach might also not make it.  The Peach Leaf Curl didn't kill it.  Canker might.  If so, I think this will be a good spot for a plum.  If  Toka doesn't make it, that will also be a spot for one of the new grafts getting TLC.

That seems like a lot.  I could easily use up the entire 2 acres, but I can't take care of that many.  This year I was not able to water enough, which might have contributed to a couple of deaths and some of the non-thriving trees.  Definitely Montmorency cherry and Saijo persimmon were stressed, but they look like they will make it.  The multigraft apples on the other side of the road, had very little watering but lived.  They are still young.  One is Chehalis + Akane + Jonagold + Summerred + Fuji, the other is the one described about with 2 semi-unknowns.

There is also a Jonagold on M27 in a flower border that contains 3 young columnar trees.  I think that will come out, and a new columnar that I grafted last year will replace it.

All images on this page are public domain, via U.S. Department of Agriculture Pomological Watercolor Collection. Rare and Special Collections, National Agricultural Library, Beltsville, MD 20705.  They either illustrate varieties I have, or might obtain, or I used as general illustration for that species.  Illustrations are late 19th and early  20th centuries.

Home Orchard Society Fruit Tasting Show. 10.18.15

Great fruit show last weekend.  Home Orchard Society.  I volunteered at the membership table for the morning.  Didn't know what I was doing but everyone was nice.

Seed Starting in Fall. 10.20.15

Seedlings.  10.20.15

 Sometimes after a rough day, I putter around the seedlings and it gives me some peace.  So many people are such anal orifices.   Plants are just plants.

Days are getting shorter.  Nothing I can do outside after or before work.   I can putter with seedlings.

I've never done this before, with daylilies.   I did grow some native plum seedlings over the winter, a few years ago.

When the daylily seeds have stratified for one month in the refrigerator, I place them at room temp in their paper towel / zipper bags.   Check the seeds every couple of days.  Many sprout within one to two weeks.  When I see sprouts, I transfer the sprouted seed to a 6-pack containing seed starting medium.  Some of those have sprouted and grown large enough that I move them up to a starting pot with potting soil.  When in seed starting medium, I water with 1/4 teaspoon of tomato miracle grow per gallon of water.

Seedlings.  10.20.15

Some were too close to the lights, resulting in a few light-burned leaves.  Not enough to set them back significantly.

So far, 3 apricot seeds have germinated.  Of Daylilies, I now have 1 dozen seeedlings from pod parent "Happy Returns", and 6 seedlings from pod parent "Chicago Apache".  There are germinated seeds from "Ice Carnival" and one from "Vigaro-labeled" NOID.  Each pod parent was hybridized with a contrasting variety, diploid to diploid and tetraploid to tetraploid.

There is also a cactus that was rootstock for a pink grafted cactus.  The scion eventually died, and the rootstock grew new branches.  I cut off a branch, to start a new plant.  Tentative ID Hylocereus undatus but I could be wrong.  If correct, that is "Dragon fruit" cactus.