Prunus domestica, European Plum
Zone
  5/3 (2b)
Pollination
  self-sterile, slightly self-fertile
Blooms
  early-mid, later than most Asian plums
Yield
  3 - 6 years (clone)

European plums are believed to be native to the Caucasus region, particularly south of the mountains.   They have, however, been extensively cultivated throughout Europe for over 2000 years.   Rainfall within their native range can be quite variable, but it's generally between 0.5" to 2" per month during most of the year (in a fairly large area, May and June receives around 3" each month).   The average July high ranges between 78F (25.6C) and 88F (31.1C).

In France and England, where plums were widely cultivated, rainfall is generally 2" to 2.5" per month during most of the grow season.   The average July high resides around 75F (23.9C).  

There are multiple European plum subspecies.   The following four are the most common, and their descriptions should be typical, but there is certainly variation within the groups (most E.  plums should have a fairly firm texture - for a plum).

Prune-type (domestica): the most common type.   ranges between very sweet to sweet-tart.   good flavor.   blue or purple skin.   can be fairly large (2").
Gage-type (italica): very sweet, good flavor.   green or yellow skin.   medium size.
Mirabelle-type (syriaca): very sweet but lacking in flavor compared to the other subspecies.   small fruit (1").   yellow, non-tart skin.
Damson-type (insititia): sweet-tart flesh.   astringent or bitter, blue or purple skin.   primarily used for processing.




Prunus salicina, Japanese Plum
Zone
  5/2 (1b)
Pollination
  self-sterile, partially self-fertile
Blooms
  early
Yield
  1 - 3 years ( clone)

Japanese plums are native to the Yangtze River basin.   From there, they were brought to the rest of eastern China where they were cultivated for 3000 years.   Most of the region is exceedingly wet during the grow season, yet "Japanese" plums aren't nearly as disease resistant as some of the other fruit that originated in a similar area (kiwis and asian persimmons).   The primary cause of brown rot on stone fruits (Monilinia fructicola) was not identified in China until 2005, giving P. salicina no time to develop resistance on their own.

The average July high within the area generally resides around 90F (32.2C).




Prunus spp, plum
  (additional notes)
Asian and, even more so, European plums are highly susceptible to disease in hot, wet climates, while plum species from eastern North America (and possibly some of their hybrids) are fairly resistant.   Tree diseases can be deadly, but the process is generally slow, giving them many years to produce.   Fruit diseases, particularly brown rot, are much more of a nuisance.   Stone fruits are most susceptible during the last 2 or 3 weeks before ripening.   Higher sugar content will increase susceptibility as well.   Brown rot can be active in a wide range of temperatures, but activity begins to decrease below 68F (20C) and above 77F (25C).  

Giving the fruit good sun exposure and planting the most resistant cultivars will help, however, it may be impossible to get plums from Asian and European species in the southeastern quarter of the United States without the use of fungicides, and even then, the most susceptible may continue to struggle.   Some of the hybrids that may be able to thrive in such an environment require low chilling, making them inappropriate for more inland areas since they tend to wake up from dormancy too early to avoid frost damage.   Chickasaw plums (Prunus angustifolia) and a few of their hybrids, such as Robusto and Excelsior, are the only ones I know of that have a very high chance of thriving (as they are native to the area).

Most Asian and European plums (and probably hybrids as well) are also somewhat susceptible to cracking.   Assuming disease is under control, you should be able to get a decent crop regularly, but a poorly timed rainfall around maturity can ruin most of your plums.   The best way to avoid this issue is to plant multiple cultivars that ripen at different times.   Even a few days difference may be able to help.   In some cases, a crop of mature fruit from one cultivar can be completely ruined, while a mature crop from another can be quite fine, but the same results may not be repeated elsewhere.

"Self-fertile" plums are often quite unreliable when planted alone.   You are better off assuming they are self-sterile and just get a second, compatible cultivar for cross-pollination.   European plums (Prunus domestica) cannot pollinate any other common plum species (and vice-versa), but the other species can typically pollinate each other, to some extent, as long as their bloom overlaps.   In some cases, plum cultivars from the same species cannot pollinate each other.   American hybrids are self-sterile and most will struggle to pollinate each other.   You will have to use a wild north american (e.g.  Prunus Americana and Prunus Nigra) or asian species (with an overlapping bloom) for cross-pollination.

American hybrids are more reliable producers than Japanese plums in climates that regularly experience late frost.   They bloom slightly later and I suspect they have additional resistance to cold temperatures as well (semi-confirmed in some cases).   European plums bloom later than both.

I am currently unaware of a single American or Asian x American hybrid that doesn't have tart skin, but the level of tartness can vary between cultivars.   The skin of many, but not all, Asian plums are probably tart to some degree, and I believe the skin of most popular European plums are non-tart or somewhat tart.

Plums that ripen "very late" may struggle to mature in areas with roughly 140 or less frost free days and an average July high in the low 80F's.



Read More

European Plum
Prunus domestica

Autumn Sweet

Zone
:
3b (3a)
Ripens
🍏:
late (mid-late)   :   precocious?

Texture
:
crisp
Color
:
dark purple or blue skin
stores well?

Bavay's Green Gage

Originated in Belgium
Zone
:
4?
Ripens
🍏:
very late   :   can hang for several weeks

Color
:
yellow-green skin
Tree Size
:
semi-dwarf
Fruit Size
:
1.25" x 1.25"
gage-type

Blau De Belgique

Bred in Belgium (1850)
Alias
:
Belgian Purple
Ripens
🍏:
mid?

Color
:
purple skin
Stone
:
freestone or semi-freestone

Blue Byrd

non-patented
Zone
:
5
Ripens
🍏:
mid-late   :   somewhat precocious?

Color
:
dark purple to blue skin
Fruit Size
:
2" long
Afflictions
:
Very resistant to black knot.

Blues Jam

Furst x unknown. Introduced in New York.
Zone
:
5
Ripens
🍏:
very late

Flavor
:
somewhat astringent
Color
:
dark purple or blue skin
Stone
:
freestone

Fruit Size
:
20g/fruit
Afflictions
:
Somewhat resistant to black knot and possibly brown rot (has at least a little more resistance than the average plum).
Damson-type plums, like Blue Jam, are generally used for processing.

highly productive, stores well

Cambridge Gage

Blooms
💮:
mid-late?   :   later or hardier than other gage-type plums
Ripens
🍏:
mid-late

Color
:
green skin
Tree Size
:
semi-dwarf
gage-type

Castleton

Valor x Iroquois.  Developed in New York (1993).
Zone
:
4 (3)
Ripens
🍏:
mid (mid-late)   :   precocious, hangs well, may ripen asynchronously

Texture
:
firm
Color
:
purple or blue skin
Stone
:
freestone

Tree Size
:
medium vigor, spreading, heavy spurring
Fruit Size
:
1.8" H x 1.4" W (4.6cm x 3.6cm)
Yield
:
4th leaf on Myrobolan seedlings
Afflictions
:
Resistant to black knot.   Resistant to bacterial spot?

Coe's Golden Drop

Originated in England (1800)
Zone
:
5
Ripens
🍏:
very late

Texture
:
juicy
Color
:
yellow skin, purple blush
Stone
:
freestone

Fruit Size
:
2" x 2"
Afflictions
:
Somewhat resistant to black knot.

Count Althann's Gage

Alias
:
Reine Claude Conducta
Zone
:
3b (3a)
Ripens
🍏:
mid-late?

Texture
:
somewhat crisp
Color
:
pink-purple skin
gage-type

Early Italian

Originated near Yakima, Washington, introduced in 1935.
Zone
:
5
Ripens
🍏:
late? (mid-late)   :   1 to 2 weeks before Italian.
Chill
:
800

Flavor
:
sweeter than Italian
Color
:
dark purple to blue skin
Stone
:
freestone

Early Laxton

Zone
:
4
Ripens
🍏:
early?   :   one of the first euro plums to ripen

Color
:
orange-yellow skin with a heavy red-pink blush
Stone
:
freestone
Afflictions
:
Susceptible to bacterial canker.

Empress

President x Emily.  
Zone
:
5
Ripens
🍏:
very late   :   at least somewhat precocious

Color
:
dark purple to blue skin
Stone
:
semi-freestone

Fruit Size
:
2" H x 1.5" W
Storage
:
2 months

Ersinger

Originated in Germany
Zone
:
5 (4)
Ripens
🍏:
mid? (early-mid)

Color
:
purple skin or blue skin
Fruit Size
:
1.5"H x 1.25"W

Ewing Blue

Zone
:
4a
Ripens
🍏:
mid? (early-mid)

Color
:
dark purple or blue skin
Stone
:
freestone?

Geneva Mirabelle

Selected in New York (1950)
Zone
:
5 (4)
Ripens
🍏:
mid-late?

Color
:
orange-yellow skin, heavy purple-red blush
Stone
:
freestone
mirabelle-type

Golden Transparent Gage

Zone
:
4?
Ripens
🍏:
very late

Color
:
yellow skin, red blush
Tree Size
:
semi-dwarf
gage-type

Gras Romanesc

Zone
:
5 (4)
Ripens
🍏:
mid-late

Texture
:
somewhat crisp
Color
:
purple skin
Fruit Size
:
1"
stores well

Gros Ameliorat

Developed in Romania
Zone
:
5
Ripens
🍏:
late?

Color
:
purple skin
Stone
:
clingstone
Fruit Size
:
1"

Honeysweet

Bluebyrd x open pollination.  Developed in Kearneysville, West Virginia, PP15154 (2001).
Zone
:
5 (4)
Ripens
🍏:
mid-late   :   1 week before Bluebyrd

Texture
:
firm
Stone
:
freestone to semi-freestone

Tree Size
:
16ft H x 8.85ft W (4.9m x 2.7m) on 7 year tree
Fruit Size
:
2" H x 1.5" W, 50-60g/fruit
Yield
:
31.75 lb/tree (14.4kg) on the 8th year
Afflictions
:
Very resistant plum pox virus (GMO).   Resistant to black knot.
Resistance to the Plum Pox Virus was obtained through genetic engineering.   It is the first genetically modified plum cultivar to be released to the public, which makes plums the second genetically modified fruit available (papayas being the first).

Imperial Epineuse

Originated in the Clairac commune of France (1870)
Zone
:
4a (4b)
Ripens
🍏:
mid-late

Color
:
blue or maroon skin
Stone
:
freestone

Italian

Zone
:
4
Ripens
🍏:
very late? (late)
Chill
:
800

Color
:
dark purple to blue skin
Stone
:
freestone

Jam Session

Late Muscatel x open pollination.  
Zone
:
5
Ripens
🍏:
late   :   biennial
hangs well?

Color
:
dark blue or purple skin
Stone
:
freestone or semi-freestone

Fruit Size
:
7/8" L x 3/4" W, 15g/fruit
Afflictions
:
Resistant to black knot.   Somewhat resistant to brown rot.
non-astringent Damson-type

Jefferson

Developed in New York
Zone
:
5
Blooms
💮:
early?   :   may bloom earlier than other European plums for some people (along with Asian plums).   bloomed normally further north.
Ripens
🍏:
  .......   :   earlier than other Gage plums.
precocious?

Color
:
yellow skin
Afflictions
:
Somewhat resistant to black knot.
Reports on Jefferson plum have been quite disappointing (bland).

gage-type

Jubileum

Developed in Sweden
Zone
:
4
Ripens
🍏:
mid (mid-late)   :   biennial (may not be as sensitive as the Victoria plum)

Color
:
burgundy skin of various shades
Stone
:
freestone?
stores well
victoria-type?

Kenmore

Zone
:
5
Ripens
🍏:
late

Stone
:
freestone
Afflictions
:
Somewhat resistant to black knot.
Kenmore is similar but superior to Stanley in many ways (such as productivity, disease resistance, etc...), with one exception being flavor, both of which are inferior to many other cultivars.

Kirke's Blue

Originated in England (1830)
Ripens
🍏:
mid?
Texture
:
juicy
Color
:
purple or blue skin
Stone
:
freestone

Long John

Bred in New York (1993)
Zone
:
5
Ripens
🍏:
late

Color
:
purple or blue skin
Stone
:
freestone

Tree Size
:
semi-dwarf (10-12ft tall)
Fruit Size
:
50g/fruit
Afflictions
:
Resistant to bacterial spot.  
Susceptible to bacterial canker.

Middleburg

Ripens
🍏:
very late   :   probably later than many other "very late" plums
Color
:
blue or dark purple skin
Fruit Size
:
1.5" x 1.5"
Afflictions
:
Somewhat resistant to black knot.

Mirabelle De Nancy

Originated in France during the 1800's
Zone
:
5
Ripens
🍏:
mid-late?

Color
:
yellow skin
Stone
:
freestone
Fruit Size
:
1"
mirabelle-type

Moldavian

Ripens
🍏:
very late? (late)
Color
:
purple-pink skin
Stone
:
freestone
Tree Size
:
semi-dwarf

Monsieur Hatif

Originated in France
Alias
:
Early Orleans
Ripens
🍏:
mid?

Color
:
purple skin? possibly maroon or burgundy
Stone
:
freestone

Mount Royal

Discovered in Quebec before 1903, possibly before 1850
Zone
:
4a
Ripens
🍏:
mid   :   probably somewhere between 1.5 to 3 weeks after Opal

Color
:
dark purple to blue skin
Stone
:
freestone or semi-freestone, small pit

Tree Size
:
semi-dwarf
Fruit Size
:
1", 23g
Afflictions
:
Susceptible to black knot.

Northern Blue

Mount Royal x open pollination. Developed in Wyoming.
Zone
:
3?
Ripens
🍏:
  .......   :   contradicting reports, early-mid to mid-late.
precocious

Color
:
blue skin
Tree Size
:
semi-dwarf

Opal

Oullins Gage x Early Favourite. Bred in Alnarp, Sweden (1925).
Zone
:
3b   :   died back to the ground at -40F (-40C) = 3a, bordering 2b
Ripens
🍏:
early-mid   :   may ripen asynchronously and may drop when ripe.
precocious?

Texture
:
juicy
Color
:
burgundy skin
Stone
:
semi-freestone

Fruit Size
:
up to 1.5"
Afflictions
:
Somewhat resistant to plum pox virus?
1/2 gage-type

Oullins Gage

unknown parentage. Discovered in France (1850's).
Alias
:
Reine Claude de Oullins
Zone
:
4
Ripens
🍏:
early-mid

Color
:
green skin
Afflictions
:
Susceptible to bacterial spot.
gage-type

Parfume De September

Ripens
🍏:
late?   :   2 weeks after other Mirabelle plums
Color
:
yellow skin
Fruit Size
:
1"
Afflictions
:
Susceptible to black knot.
mirabelle-type

Petite Soeur De La Mont Royal

Zone
:
3b
Ripens
🍏:
early-mid?   :   possibly 1 or 2 weeks before Mount Royal
Petite Soeur de la Mont Royal is believed to be a (more cold hardy) seedling of Mount Royal with similar quality.

President

Zone
:
5
Ripens
🍏:
very late

Color
:
dark purple or blue skin
Stone
:
semi-freestone?
Afflictions
:
Resistant to black knot.
President is grown commercially in the Northwest.

Purple Gage

Alias
:
Reine Claude Violette
Ripens
🍏:
mid-late

Color
:
purple or blue skin
Stone
:
freestone, small pit
gage-type

Reine Claude Doree

Zone
:
5
Ripens
🍏:
mid-late?
Color
:
yellow-green skin
gage-type

Reine De Mirabelle

Zone
:
5
Blooms
💮:
mid-late
Ripens
🍏:
late?   :   1 or 2 weeks after other Mirabelle plums

Color
:
yellow skin
Fruit Size
:
larger than other mirabelle plums
Afflictions
:
Resistant to black knot.
Reine de Mirabelle is a cross between a mirabelle-type plum and a gage-type.

Rosy Gage

Imperial Epineuse x unknown.  
Zone
:
5
Ripens
🍏:
mid-late   :   ripen asynchronously

Texture
:
soft flesh
Color
:
pink-purple skin
Afflictions
:
Very susceptible to brown rot and black knot.

Sanctus Hubertus

Originated in Belgium
Ripens
🍏:
mid?
Color
:
blue or dark maroon skin

Schoolhouse

Discovered in Washington
Ripens
🍏:
mid
Color
:
yellow skin

Seneca

Fellenberg x Prinlew. Introduced in New York (1972)
Zone
:
4 (3)
Ripens
🍏:
mid-late

Color
:
purple or burgundy skin
Tree Size
:
semi-dwarf?
Fruit Size
:
very large
Afflictions
:
Resistant to black knot.

Stanley

Agen x Grand Duke. Introduced in Geneva, New York (1926).
Zone
:
4a
Ripens
🍏:
late   :   precocious?
Chill
:
800

Color
:
purple to blue skin
Stone
:
freestone
Afflictions
:
Resistant to bacterial spot.  
Susceptible to black knot.

Valerie

Valor x California Blue. Originated in Vineland, Ontario. V70031
Zone
:
5?
Ripens
🍏:
mid   :   drops shortly after maturing

Color
:
purple or blue skin
Stone
:
semi-freestone to clingstone
Afflictions
:
Susceptible to bacterial spot.
Valerie supposedly produces a fairly large plum for an early ripening cultivar, but I wonder about its flavor considering it is mentioned for being mild and lacking in acidity.   How does it compare to other early ripening cultivars?

Valerie appears to be less cold hardy than most other cultivars.   Overall, it is highly experimental, most of what we do know at this time leans on the negative side.

Valor

Imperial Epineuse x Grand Duke. Developed in Vineland, Ontario (1967).
Zone
:
4
Ripens
🍏:
very late

Color
:
dark purple skin
Stone
:
semi-freestone
Afflictions
:
Resistant to bacterial spot.  
Susceptible to black knot.

Vanette

Early Rivers x Stanley. Developed in Vineland, Ontario. V66071
Zone
:
5?
Ripens
🍏:
mid (mid-late)   :   a few days after Valerie

Color
:
purple or blue skin
Stone
:
freestone
Afflictions
:
Resistant to bacterial spot.

Victoria

Discovered in England (1840)
Ripens
🍏:
mid-late   :   biennial
Color
:
pink-red skin, golden yellow blush
Stone
:
freestone or semi-freestone
victoria-type

Victory

Vision x Valor.  
Zone
:
5
Ripens
🍏:
late   :   precocious

Color
:
purple-pink skin
Stone
:
semi-freestone
Fruit Size
:
2"

Violette

Originated in Vineland, Ontario. V72511
Zone
:
5?
Ripens
🍏:
mid?

Color
:
purple-pink skin
Stone
:
semi-freestone
Fruit Size
:
large

Vision

Zone
:
5
Ripens
🍏:
very late

Color
:
dark purple skin
Stone
:
freestone, small pit

Fruit Size
:
1.5" x 1.5", 55g
Afflictions
:
Resistant to bacterial spot.  
Somewhat susceptible to black knot?

Voyageur

Developed in Vineland, Ontario
Zone
:
5
Ripens
🍏:
mid (mid-late)   :   drops when mature

Japanese Plum
Prunus salicina

Beauty

Zone
:
5
Blooms
💮:
early-mid
Ripens
🍏:
early-mid   :   precocious
Chill
:
250

Color
:
red skin, red flesh
Afflictions
:
Resistant to black knot.
Beauty tends to lack flavor, although, some have claimed that it develops good flavor if grown in a region that receives high temperatures early in the grow season.

Brookgold

Introduced in Brooks, Alberta (1979)
Zone
:
2a
Ripens
🍏:
early-mid?

Color
:
yellow skin
Stone
:
freestone
Fruit Size
:
1"

Burbank

The seed originated from Japan, imported to the US in 1883. Named in 1887.
Zone
:
5a
Ripens
🍏:
mid? (mid-late)   :   precocious, biennial, long harvest season
Chill
:
400

Texture
:
firm
Color
:
burgundy skin, yellow blush
Stone
:
semi-freestone or clingstone
Afflictions
:
Susceptible to bacterial spot.
Burbank is usually labeled as a Japanese plum, but I have seen two sources claim it's a plumcot.

Cocheco

Zone
:
4
Ripens
🍏:
early-mid
Color
:
red skin
ornamental maroon leaves throughout the grow season.

Crimson

Developed in Alabama
Color
:
red skin
Stone
:
clingstone
Afflictions
:
Resistant to black knot and bacterial canker.

Early Golden

Ripens
🍏:
early   :   biennial
Texture
:
firm
Color
:
yellow skin, red blush
Stone
:
freestone

Fruit Size
:
28g/fruit
Afflictions
:
Susceptible to bacterial spot.

Elephant Heart

Originated in Sebastopol, California (1929). unpatented.
Zone
:
5
Blooms
💮:
early-mid
Ripens
🍏:
mid-late?   :   hangs well
Chill
:
500

Color
:
tan skin to a dark red-purple as it fully ripens, red flesh
Stone
:
freestone
Afflictions
:
Susceptible to black knot.

Emerald Beaut

Wickson x 3W32LC (Red Beaut x open pollination).  Developed in California, PP9162 (1994).
Zone
:
5?
Blooms
💮:
early-mid
Ripens
🍏:
late?
Chill
:
600 - 700

Texture
:
firm, crisp
Color
:
yellow-green skin
Stone
:
nurseries say freestone, patent says clingstone

Fruit Size
:
2.5"
Afflictions
:
Susceptible to black knot.
Emerald Beaut plums can hang on the tree for roughly 2 months after they mature, and the longer they remain, the sweeter they get.   They also retain much of their original crisp and crunchy texture as they hang.

Fofonoff

Developed in Buchanan, Saskatchewan (1973)
Zone
:
2a (1a)
Ripens
🍏:
early-mid?

Color
:
yellow skin
Stone
:
clingstone

Fortune

Originated in Fresno, California (1988). unpatented.
Zone
:
5?
Ripens
🍏:
late
Chill
:
500

Texture
:
firm
Color
:
purple-red skin, yellow blush
Stone
:
semi-freestone or clingstone
Afflictions
:
Susceptible to bacterial spot.

Golden Nectar

seedling of Mariposa.  Discovered in California, PP4977 (1981).
Zone
:
5
Ripens
🍏:
very late   :   may not ripen in cool summer climates
Chill
:
400 - 500

Texture
:
firm
Color
:
yellow skin
Stone
:
freestone, small pit
Fruit Size
:
2.4" diameter

Ivanovka

Developed in Morden, Manitoba (1939)
Zone
:
2a
Texture
:
firm
Color
:
yellow skin? red blush?
Stone
:
semi-freestone

Mariposa

Alias
:
Improved Satsuma
Zone
:
4?
Blooms
💮:
early-mid
Ripens
🍏:
mid?   :   can hang for up to 3 weeks
Chill
:
250 - 300

Color
:
red-purple skin over green, red flesh
Stone
:
freestone, small pit

Fruit Size
:
large
Afflictions
:
Susceptible to black knot.
Mariposa is also known as Improved Satsuma, but it currently appears that, when it comes to flavor, the original Satsuma is superior.

Methley

Zone
:
4
Ripens
🍏:
very early
Chill
:
150 - 250

Texture
:
juicy
Color
:
red-purple skin, red flesh
Stone
:
clingstone
Afflictions
:
Very susceptible to black knot.

NY 1502

Abundance x Methley. Developed in New York.
Zone
:
5?
Ripens
🍏:
early?
Color
:
yellow skin, red blush
NY 1502 is a possible replacement for "Early Golden".

Ozark Premier

Burbank x Methley. Introduced in Missouri (1946).
Zone
:
5
Ripens
🍏:
mid-late   :   precocious, hangs well
ripens asynchronously?

Color
:
burgundy skin
Stone
:
clingstone, small pit

Fruit Size
:
2"
Afflictions
:
Susceptible to bacterial spot.
Ozark Premier supposedly develops a better flavor when excessive fruit production is thinned out early.

Ptitsin 5

Zone
:
3? (2)
Ripens
🍏:
early-mid?

Texture
:
firm
Color
:
green skin
Stone
:
freestone
Ptitsin #5 stores well for an Asian plum, but they do not hang well.   let them ripen on the counter for a few days.

Santa Rosa

non-patented
Zone
:
5b
Blooms
💮:
early-mid?
Ripens
🍏:
early-mid   :   around Redhaven peach
Chill
:
300

Texture
:
firm
Color
:
burgundy skin
Afflictions
:
Susceptible to black knot.
In addition to the skin (which is quite common for Asian and American plums), the flesh near the stone of Santa Rosa is also tart.

Satsuma

Originated in Japan, Introduced to the US in 1889. non-patented.
Zone
:
4? (5a)
Ripens
🍏:
mid? (early-mid)
Chill
:
300

Color
:
dark burgundy skin, red flesh
Stone
:
semi-freestone or clingstone
Afflictions
:
Somewhat resistant to black knot.

Shiro

Originated in California (1899). non-patented.
Zone
:
5? (4)
Ripens
🍏:
early-mid   :   highly contradicting reports on ripening dates, but should be 0 to 1 week before Redhaven peach.
Chill
:
400 - 500

Texture
:
juicy
Color
:
yellow skin
Stone
:
clingstone
Afflictions
:
Resistant to black knot.  
Somewhat susceptible to brown rot (less susceptible than most plums)?
I don't know if it was picked too early, watered too much, or mislabeled, but in my limited experience, Shiro was a horrible plum.   People only seem to grow this variety because it's widely known for being a very reliable producer, otherwise they prefer the flavor of other plums.

I believe the ones I tried were quite yellow, not primarily orange.   It sounds like if you let them hang long enough for them to turn orange-yellow, they're alright.

Vampire

Zone
:
4?
Ripens
🍏:
mid-late

Texture
:
juicy
Color
:
red skin, red flesh

Vanier

Wickson x Burbank.  
Zone
:
5?
Ripens
🍏:
mid-late? (mid)   :   precocious, ripens asynchronous, may drop shortly after maturing

Color
:
red skin
Stone
:
clingstone

Storage
:
2-3 weeks
Afflictions
:
Somewhat resistant to bacterial spot?
Stores well for a Japanese plum.

Weeping Santa Rosa

Zone
:
5
Ripens
🍏:
  .......   :   a few weeks after Santa Rosa
Chill
:
200 - 400

Tree Size
:
semi-dwarf (8 to 10ft tall)
Afflictions
:
Susceptible to black knot.
Weeping Santa Rosa may be superior in flavor when compared to the original Santa Rosa.

ornamental weeping form

Hybrid Plum
Prunus hybrid

Alderman

P. Salicina x P. Americana.  Originated in Minnesota. non-patented.
Zone
:
4a
Blooms
💮:
mid
Ripens
🍏:
mid   :   0 to 1 week after Toka?
precocious

Color
:
red skin, possibly with shades of orange, pink, or purple
Stone
:
clingstone
Fruit Size
:
2"
ornamental red leaves in the fall

AU Rosa

backcrosses involving Starcher No. 1 (P. angustifolia) and primarily Santa Rosa (P. salicina) or seedlings of the two.
Zone
:
5b (5a)
Ripens
🍏:
early-mid
Chill
:
700

Texture
:
firm
Color
:
burgundy skin
Stone
:
clingstone

Fruit Size
:
1.5" to 2.25"
Afflictions
:
Resistant to brown rot, black knot, bacterial spot, and sun scald.

AU Rubrum

Chill
:
700
Texture
:
firm
Color
:
burgundy skin, red flesh
Stone
:
clingstone

Fruit Size
:
2.25" to 2.5"
Afflictions
:
Resistant to bacterial canker and bacterial spot.   Resistant to black knot? Somewhat resistant to brown rot and leaf scald.
AU Rubrum is one of the better quality AU plums.

Black Ice

? (Oka (P. besseyi) x Z's Blue Giant (P. salicina)) x P. salicina.  Developed in Wisconsin, PP16621 (2004).
Alias
:
Lydecker
Zone
:
3b? (4a)
Blooms
💮:
  .......   :   self-sterile, lacks pollen
Ripens
🍏:
early-mid   :   1 week before Toka
precocious, biennial

Texture
:
tart skin, sweet flesh, juicy
Color
:
dark purple or black skin, red flesh
Stone
:
semi-freestone

Tree Size
:
dwarf, 8.2ft H x 6.6ft W (2.5m x 2m) at year 9
Fruit Size
:
2"
Afflictions
:
Resistant to bacterial spot.  
Susceptible to splitting.
Multiple reports in Alberta, Canada indicate that Black Ice is only hardy down to zone 4a in-spite of some nurseries, as well as its patent, claiming 3b.   This may ultimately be the result of a vulnerability to some other form of winter damage, considering multiple people have reported severe or complete dieback in Zones 3b to 5a while their other nearby cultivars endured perfectly fine.   Other people in Zone 4 and 5 have not experienced this problem.

Brookred

Zone
:
3a?
Ripens
🍏:
early?

Color
:
dark red skin
Stone
:
freestone
Afflictions
:
Very susceptible to splitting.
Brookred is a very unreliable plum for some people.   When it does manage to fruit, splitting becomes an issue.   The buds may have some type of vulnerability to cold temperatures or late frosts other hybrids don't seem to share.

Gulf Beauty

? (contains Ozark Premier, Burbank, Beauty, and Bruce) x Taiwan (Hung-ju x open pollination).  Developed in Florida, PP11224 (1997).
Blooms
💮:
early-mid? (early)   :   with all other gulf-series plums
Ripens
🍏:
  .......   :   Gulf Beauty is the earliest gulf plum to ripen.
roughly 2.5 months after pollination in Florida.
can hang for 7-10 days.
Chill
:
225 - 250

Flavor
:
tart, slightly bitter skin with sweet flesh
Texture
:
firm
juicy?
Color
:
burgundy skin
Stone
:
clingstone

Fruit Size
:
1.85" x 1.85" (4.7cm), 50 to 55 grams/fruit
Afflictions
:
Very resistant to bacterial canker and fruit scald.   Resistant to bacterial spot and leaf scald.

Gulf Blaze

? (contains Ozark Premier, Burbank, Beauty, and Bruce) x Taiwan (Hung-ju x open pollination).  Developed in Florida, PP10880 (1997).
Blooms
💮:
early-mid? (early)
Ripens
🍏:
  .......   :   roughly 1 to 2 weeks after Gulf Beauty
Chill
:
250

Flavor
:
sweet flesh, tart skin
Texture
:
firm
juicy?
Color
:
burgundy skin
Stone
:
semi-freestone

Fruit Size
:
2", 70-80 grams
Afflictions
:
Very resistant to bacterial canker and fruit scald.   Resistant to bacterial spot and leaf scald.

Gulf Gold

Developed in Umatilla, Florida. non-patented.
Blooms
💮:
early-mid? (early)   :   a few days after Gulf Ruby but should overlap with any gulf-series plum
Ripens
🍏:
  .......   :   3 to 4 weeks after Gulf Beauty?
Chill
:
250

Color
:
yellow skin, orange blush
Tree Size
:
semi-dwarf
Afflictions
:
Resistant to bacterial canker?
Somewhat susceptible to leaf scald.

Gulf Rose

Developed in Florida, PP12833 (2000).
Blooms
💮:
early-mid? (early)   :   a few days after most other gulf-series plums
Ripens
🍏:
  .......   :   roughly 2 to 3 weeks after Gulf Beauty
self-sterile, precocious (2nd year)
Chill
:
275

Flavor
:
sweet flesh
slightly tart skin? with no bitterness
Texture
:
firm
juicy?
Color
:
deep burgundy skin and deep burgundy flesh
Stone
:
semi-freestone

Tree Size
:
6.6ft H x 4.9ft W (2m x 1.5m) at year 3
Fruit Size
:
up to 2", 60-80 grams
Afflictions
:
Very resistant to bacterial canker and fruit scald.   Resistant to bacterial spot.  
Somewhat susceptible to leaf scald.

Gulf Ruby

Developed in Umatilla, Florida (1982). non-patented.
Blooms
💮:
early-mid? (early)
Ripens
🍏:
  .......   :   roughly 0.5 to 1 week after Gulf Beauty.
can hang for 3-5 days.
Chill
:
225

Flavor
:
sweet flesh, tart skin
Color
:
red-purple skin
Stone
:
clingstone

Fruit Size
:
up to 2"
Afflictions
:
Susceptible to bacterial canker and fruit scald.
Gulf Ruby's susceptibility to bacterial canker may limit its lifespan to 5-8 years in wet climates.

La Crescent

Shiro (P. Salicina) x Howard Yellow (P. Americana).  non-patented.
Zone
:
3b? (4a)
Blooms
💮:
mid?   :   some contradicting information on bloom time.
Ripens
🍏:
early-mid? (early)   :   highly contradicting reports on ripening time.   Probably a few weeks before Toka.
Stone
:
freestone
A few people have confirmed its mild apricot flavor, but it may not be consistent, at least in less than ideal environments.   The overall flavor and texture are considered to be inferior.

Lavina

P. cerasifera x P. salicina. Developed in Lithuania.
Zone
:
5? (4)
Blooms
💮:
early   :   slightly earlier than other hybrids, more aligned with Japanese plums.
Ripens
🍏:
early-mid   :   long harvest season

Color
:
red skin
Stone
:
freestone, small pit

Fruit Size
:
30g
Afflictions
:
Resistant to black knot.   Somewhat resistant to brown rot?

Obilnaja

P. salicina x P. cerasifera. Originated in Yalta.
Zone
:
5a
Ripens
🍏:
early-mid

Color
:
dark purple skin
Stone
:
freestone, small pit

Fruit Size
:
40g
Afflictions
:
Resistant to black knot and bacterial spot.  
Somewhat susceptible to brown rot (less susceptible than most plums)?
Obilnaja becomes well colored long before it fully ripens.

Patterson Pride

Developed in Saskatchewan, Canada (1960).
Zone
:
2
Blooms
💮:
  .......   :   hardy blossoms
Ripens
🍏:
mid? (mid-late)   :   probably around Toka

Texture
:
firm
Color
:
red skin
Stone
:
semi-freestone

Tree Size
:
semi-dwarf
Fruit Size
:
1.5" to 2"
ornamental weeping form

Pembina

Assiniboine (P. Nigra) x Red June (P. Salicina). Introduced in South Dakota (1917).
Zone
:
2b (2a)
Ripens
🍏:
mid? (early-mid)   :   biennial

Texture
:
juicy
Color
:
red skin
Stone
:
semi-freestone

Fruit Size
:
2"
Afflictions
:
Very susceptible to splitting.

Purple Heart

Zone
:
4
Blooms
💮:
mid
Ripens
🍏:
early-mid   :   hangs well

Flavor
:
low acid skin?
Texture
:
firm
Color
:
burgundy or purple skin, red flesh
Afflictions
:
Somewhat resistant to black knot.  
Somewhat susceptible to brown rot (less susceptible than most plums)?

South Dakota

P. americana x unknown. possibly not a hybrid.  Developed in South Dakota (early 1900's). Released in Minnesota (1949).
Zone
:
3
Blooms
💮:
mid?   :   extended bloom
Ripens
🍏:
mid-late?   :   after most other hybrids

Color
:
pink-red skin, orange blush
Stone
:
freestone

Sprite

P. cerasifera x P. salicina.  
Zone
:
4
Blooms
💮:
early   :   slightly earlier than other hybrids, more aligned with Japanese plums.
Ripens
🍏:
early-mid   :   long harvest season
Chill
:
400

Color
:
dark purple, blue, grey, maroon, or black skin
Stone
:
freestone
Tree Size
:
semi-dwarf (8 to 10ft tall)
Sprite plums are well colored long before they fully ripen.

Superior

Burbank (P. Salicina) x Kaga (P. Americana x P. Simonii).  Originated in Minnesota (1933). non-patented.
Zone
:
4a (3b)
Blooms
💮:
early-mid
Ripens
🍏:
mid   :   0.5 weeks before Toka
precocious, biennial, 1-2 week harvest

Texture
:
juicy
Color
:
red skin
Stone
:
clingstone

Tree Size
:
semi-dwarf with a semi-weeping form
Fruit Size
:
2" x 2", possibly larger
Superior is very precocious.   This can be a problem because the branches are weak and will struggle for a few years if the fruit aren't thinned out.   Heavy production without immediate thinning can also cause the tree to produce biennially.

Toka

P. americana x P. simonii.  Developed in South Dakota (1911).
Alias
:
Bubblegum
Zone
:
3
Blooms
💮:
mid   :   slightly later than most Japanese and hybrid plums with an extended bloom.
Toka might be a decent pollinator for other hybrids, but you're generally going to want a pure P.  nigra or P.  americana.
Ripens
🍏:
mid   :   1.5 to 2.5 weeks after Redhaven peach (in the northern half of the US)

Texture
:
firm
Color
:
burgundy skin
Stone
:
semi-freestone
Fruit Size
:
1.5"
Toka is also called "Bubblegum" because most people claim it tastes like bubblegum.   In my experience, it was certainly noticeable, but it was not the dominant flavor, and after a few days on the table, it lost its complex flavor.

ornamental red leaves in the fall?

Underwood

Shiro (Asian hybrid) x Wyant (P. Americana).  Developed in Minnesota (1921)? non-patented.
Zone
:
3
Blooms
💮:
early-mid   :   extended bloom?
Ripens
🍏:
early?   :   a few weeks before Toka?

Texture
:
juicy
Color
:
burgundy skin
Stone
:
semi-freestone or clingstone

Fruit Size
:
2"
Afflictions
:
Somewhat resistant to brown rot.
ornamental yellow leaves in the fall

Waneta

Apple (P. Salicina) x Terry (P. Americana).  Originated in South Dakota (1913).
Zone
:
3a
Blooms
💮:
mid? (early-mid)
Ripens
🍏:
mid   :   around Toka

Flavor
:
tart skin, sweet flesh
Color
:
burgundy skin
Stone
:
clingstone
Fruit Size
:
1.5" to 2"
Waneta has fairly thick, tart skin, but it's easy to peel.