Most plum species are highly susceptible to plum curculio, a pest that can easily ruin the entire crop.  It is generally located in the eastern half of the United States, and they are active for up to 6 weeks, starting shortly after bloom.  They can ruin or disfigure the crop of other species as well.  Oriental fruit moth can also be a serious problem for plums and other stonefruit.  Many varieties are quite susceptible to various forms of disease as well, with the most damaging being brown rot, which affects the fruit, and black knot, which affects the branches.  Splitting from the rain is also a frequent occurrence.  Plums require high effort to manage.

European Plums: Prunus domestica

European plums are generally susceptible to black knot, brown rot, canker, and splitting, but they bloom much later than the other species shown here.  Varieties labeled as self-fertile generally need to be cross-pollinated to produce an acceptable crop, but they are only compatible with varieties from its own species.  When grafted to most rootstocks, European plums may take a few years longer than other plums before they begin to produce.

Bavay's Green Gage

🔍
Originated in Belgium
Zone
• 4?
Ripens
🍈
• late
Color
• yellow-green skin
Growth
• semi-dwarf
Fruit
• medium-small size
• gage-type
Afflictions
• Somewhat resistant to cracking?

Blue Byrd

🔍
non-patented
Zone
• 5
Ripens
🍈
• mid-late?
• somewhat precocious?
Color
• dark purple to blue skin
Fruit
• medium-size
Afflictions
• Very resistant to black knot.

Cambridge Gage

🔍
Blooms
💮
• mid-late?     ◦ later or hardier than other gage-type plums
Ripens
🍈
• mid-late
Color
• yellow-green skin
Growth
• semi-dwarf
Fruit
• gage-type

Cambridge Gage may develop more acid than most other gage-type plums.

Castleton

🔍
Valor x Iroquois.  Developed in New York (1993).
Zone
• 4 (3)
Ripens
🍈
• mid-late (mid)
• precocious
Color
• purple or blue skin
Growth
• medium vigor, spreading, heavy spurring
Fruit
• medium-size
• freestone
Afflictions
• Resistant to bacterial spot?

The Castleton plum colors well before it is ready to harvest.

Coe's Golden Drop

🔍
Originated in England (1800)
Zone
• 5
Ripens
🍈
• very late
Color
• yellow skin, purple blush
Fruit
• medium-large size
• freestone

Count Althann's Gage

🔍
Selected in Bohemia between 1850 and 1860.
Alias
• Reine Claude Conducta
Zone
• 3b (3a)
Blooms
💮
• late
Ripens
🍈
• mid-late
Color
• pink-purple skin
Growth
• semi-dwarf
Fruit
• gage-type
Yield
• lightly productive

Early Laxton

🔍
Zone
• 4
Ripens
🍈
• early
Color
• orange-yellow skin with a heavy red-pink blush
Fruit
• freestone

Early Laxton appears to be the earliest ripening European plum available in North America, and like the others that ripen quite early (such as Opal and Ersinger), the quality is fairly good, but you may not find it to be up to par with many of those that ripen later.

Empress

🔍
President x Emily
Zone
• 5
Ripens
🍈
• very late
• at least somewhat precocious
Color
• dark purple to blue skin
Fruit
• medium-large size
• semi-freestone
Storage
• 2 months

Ersinger

🔍
Originated in Germany
Zone
• 5 (4)
Ripens
🍈
• early-mid     ◦ probably after Opal
Color
• purple skin or blue skin

Golden Transparent Gage

🔍
Zone
• 4?
Ripens
🍈
• very late
Color
• yellow skin, red blush
Growth
• semi-dwarf
Fruit
• gage-type

Imperial Epineuse

🔍
Originated in the Clairac commune of France (1870)
Zone
• 4a (4b)
Ripens
🍈
• mid-late
Color
• blue or maroon skin
Fruit
• freestone

Jefferson

🔍
Developed in New York
Zone
• 5
Ripens
🍈
• very late
Fruit
• gage-type

The "Jefferson plum" has had mislabeling issues, but it's supposed to be a gage-type plum.  The wrong version appears to have traits that are more inline with that of an Asian plum, and they were allegedly sourced from L.E. Cook and Trees of Antiquity.  I do not know if this is still a problem at present or if other nurseries were involved.

Jubileum

🔍
Developed in Sweden
Alias
• Jubilee
Zone
• 4
Ripens
🍈
• mid (mid-late)     ◦ ~1 week before Victoria
• biennial
Color
• burgundy skin of various shades
Fruit
• freestone?
• victoria-type?

Jubileum may not be as biennial as the Victoria plum.

Kirke's Blue

🔍
Originated in England (1830)
Ripens
🍈
• mid-late? (late)
Color
• purple or blue skin
Fruit
• freestone

Long John

🔍
Bred in New York (1993)
Zone
• 5
Ripens
🍈
• late
Color
• purple or blue skin
Growth
• semi-dwarf
Fruit
• freestone
Afflictions
• Resistant to bacterial spot.

Middleburg

🔍
Ripens
🍈
• extremely late
Color
• blue or dark purple skin
Fruit
• medium-size

Most zone 5 and some zone 6 areas in the US will not have a grow season warm or long enough to properly ripen the Middleburg European plum — as well as those labeled as "very late".

Mirabelle De Nancy

🔍
Originated in France during the 1800's
Zone
• 5
Ripens
🍈
• mid-late? (late)
Color
• yellow skin
Growth
• semi-dwarf
Fruit
• small-size
• freestone
• mirabelle-type

Mount Royal

🔍
Discovered in Quebec before 1903 (possibly before 1850)
Zone
• 4a
Ripens
🍈
• mid-late (mid)
Color
• dark purple to blue skin
Growth
• semi-dwarf
Fruit
• medium-small size
• freestone or semi-freestone, small pit

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     ◦ probably between Early Laxton and Ersinger
• precocious?
Color
• burgundy skin
Fruit
• medium-small size
• semi-freestone
Afflictions
• Somewhat resistant to plum pox virus?

Opal is preferred for its relatively early ripening and cold hardy traits rather than its flavor, but it is supposed to produce a decent plum.

Oullins Gage

🔍
unknown parentage.  Discovered in France (1850's).
Alias
• Reine Claude de Oullins
Zone
• 4
Ripens
🍈
• mid     ◦ earlier than most gage-type plums
Color
• green skin
Fruit
• gage-type
Afflictions
• Susceptible to bacterial spot.

Oullins Gage is a fairly controversial variety that is often reputed to not taste as good as the other gage-type plums, but some people are quite fond of them and it does have the advantage of ripening early in comparison.

Parfume De September

🔍
Ripens
🍈
• late?
Color
• yellow skin
Fruit
• small-size
• mirabelle-type

President

🔍
Zone
• 5
Ripens
🍈
• very late
Color
• dark purple or blue skin
Fruit
• medium-size? (smaller than its offspring, Empress)
• semi-freestone?
Afflictions
• Resistant to black knot.

President is grown commercially in the Northwest.

Purple Gage

🔍
Alias
• Reine Claude Violette
Ripens
🍈
• mid-late? (late)
Color
• purple or blue skin
Fruit
• gage-type
• freestone, small pit

Reine Claude Doree

🔍
Zone
• 5
Ripens
🍈
• mid-late? (late)
Color
• yellow-green skin
Fruit
• gage-type

Reine Claude Doree was once said to be the "original" Old Green Gage, but I am not quite sure if this is accurate.  I need to look over this once again.

Reine De Mirabelle

🔍
Zone
• 5
Blooms
💮
• mid-late
Ripens
🍈
• late?     ◦ 1 or 2 weeks after other Mirabelle plums
Color
• yellow skin
Fruit
• larger than other mirabelle plums

Reine de Mirabelle is a cross between a mirabelle-type plum and a gage-type, but it supposedly tastes more like a gage.

Rosy Gage

🔍
Imperial Epineuse x unknown
Zone
• 5
Ripens
🍈
• mid-late
Color
• pink-purple skin
Afflictions
• Highly susceptible to brown rot and black knot.

Seneca

🔍
Fellenberg x Prinlew.  Introduced in New York (1972).
Zone
• 4 (3)
Ripens
🍈
• mid-late
Color
• purple or burgundy skin
Growth
• semi-dwarf?
Fruit
• medium-large size
Afflictions
• Resistant to black knot.

Stanley

🔍
Agen x Grand Duke.  Introduced in Geneva, New York (1926).
Zone
• 4a     ◦ 800 chill hours
Ripens
🍈
• late
Color
• purple to blue skin
Fruit
• freestone
Afflictions
• Resistant to bacterial spot.

Stanley isn't exactly considered to be a high quality plum, and while Kenmore isn't either, it is a more productive version of Stanley that has some resistance to black knot (a very important trait that isn't too common with European plums).

Valor

🔍
Imperial Epineuse x Grand Duke.  Developed in Vineland, Ontario (1967).
Zone
• 4
Ripens
🍈
• late
Color
• dark purple skin
Fruit
• semi-freestone
Afflictions
• Resistant to bacterial spot.

AC Nursery sold a plum mislabeled as Valor for at least a few years, but I believe the issue was officially corrected in 2020.

Victoria

🔍
Discovered in England (1840)
Ripens
🍈
• mid-late
• biennial
Color
• pink-red skin, golden yellow blush
Fruit
• victoria-type
• freestone or semi-freestone

Victory

🔍
Vision x Valor
Zone
• 5
Ripens
🍈
• late
• precocious
Color
• purple-pink skin
Fruit
• medium-size
• semi-freestone

Vision

🔍
Zone
• 5
Ripens
🍈
• very late     ◦ 0.5 to 1 week before President
Color
• dark purple skin
Fruit
• medium-size
• freestone, small pit
Afflictions
• Resistant to bacterial spot.

Asian Plums: Prunus salicina

Susceptible to black knot, brown rot, canker, and splitting.  Blooms quite early in the season.

Beauty

🔍
Zone
• 5     ◦ 250 chill hours
Blooms
💮
• early-mid
Ripens
🍈
• early-mid
• precocious
Color
• red skin, red flesh
Afflictions
• Resistant to black knot.

Beauty tends to lack flavor, but this may not be the case when it is grown in a region that receives high temperatures early in the grow season.

Burbank

🔍
The seed originated from Japan and was imported to the US in 1883.  The variety was named in 1887.
Zone
• 5a     ◦ 400 chill hours
Ripens
🍈
• mid? (mid-late)
• biennial
• long harvest season
• precocious
Color
• burgundy skin, yellow blush
Fruit
• semi-freestone or clingstone
Afflictions
• Susceptible to bacterial spot.

Burbank is a Japanese plum, but there is a plumcot that is sometimes called 'Burbank' as well.  Its real name is supposedly 'Apex'.

Early Golden

🔍
Ripens
🍈
• early
• biennial
Color
• yellow skin, red blush
Fruit
• 28g/fruit
• freestone
Afflictions
• Susceptible to bacterial spot.

Elephant Heart

🔍
Originated in Sebastopol, California (1929).  unpatented.
Zone
• 5     ◦ 500 chill hours
Blooms
💮
• early-mid
Ripens
🍈
• mid-late?
• hangs well
Color
• dark red-purple skin with a tan bloom and red flesh
Fruit
• large-size
• freestone

Emerald Beaut

🔍
Wickson x 3W32LC (Red Beaut x open pollination).  Developed in California.  PP9162 (1994).
Zone
• 5?     ◦ 600-700 chill hours
Blooms
💮
• early-mid
Ripens
🍈
• late?
Color
• yellow-green skin
Fruit
• large-size
• nurseries say freestone, patent says clingstone

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 texture as they hang.

Golden Nectar

🔍
seedling of Mariposa (Improved Satsuma).  Discovered in California.  PP4977 (1981).
Zone
• 5     ◦ 400-500 chill hours
Ripens
🍈
• very late
• may not ripen in cool summer climates
Color
• yellow skin
Fruit
• large-size
• freestone, small pit

Methley

🔍
Zone
• 4     ◦ 150-250 chill hours
Ripens
🍈
• very early
Color
• red-purple skin, red flesh
Fruit
• clingstone
Afflictions
• Highly susceptible to black knot.

Ozark Premier

🔍
Burbank x Methley.  Introduced in Missouri (1946).
Zone
• 5
Ripens
🍈
• mid-late
• hangs well
• precocious
• ripens asynchronously?
Color
• burgundy skin
Fruit
• medium-size
• clingstone, small pit
Afflictions
• Somewhat resistant to black knot and bacterial canker.
Susceptible to bacterial spot and leaf scald.

Thinning out excessive fruit production can improve the quality of Ozark Premier, but this is occasionally mentioned about a number of varieties from various species.

Santa Rosa

🔍
non-patented
Zone
• 5b     ◦ 300 chill hours
Blooms
💮
• early-mid?
Ripens
🍈
• early-mid
Color
• burgundy skin

In addition to the skin, 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)     ◦ 300 chill hours
Ripens
🍈
• mid? (early-mid)
Color
• dark burgundy skin, red flesh
Fruit
• semi-freestone or clingstone

Shiro

🔍
Originated in California (1899).  non-patented.
Zone
• 5? (4)     ◦ 400-500 chill hours
Ripens
🍈
• early-mid     ◦ about a week before Redhaven in parts of the Northeast
Color
• yellow skin
Fruit
• clingstone
Afflictions
• At least somewhat resistant to black knot.
Less susceptible to brown rot than most plums?

People only seem to grow this variety because it's widely known for being a reliable producer, otherwise they prefer the flavor of other plums.  It sounds like if you let them hang long enough for them to turn orange-yellow, they're alright.

Weeping Santa Rosa

🔍
Zone
• 5     ◦ 200-400 chill hours
Ripens
🍈
•    ◦ a few weeks after Santa Rosa
Growth
• semi-dwarf (8 to 10ft tall)

Weeping Santa Rosa may have a superior flavor than the original Santa Rosa.

North American Hybrid Plums

American hybrid plums generally have strong resistance to black knot and above average resistance to canker, but they are probably susceptible to splitting under certain conditions.  Furthermore, they bloom relatively late and may have slightly more resistance against frost damage than many other species.  Production issues involving self-sterility, poor pollen production, and genetic incompatibility are quite common.  A pure Prunus americana plum is recommended for pollination, but Asian plums with an overlapping bloom may work as well.

Alderman

🔍
P. Salicina x P. Americana.  Originated in Minnesota.  non-patented.
Zone
• 4a
Blooms
💮
• mid
Ripens
🍈
• mid     ◦ shortly after Toka and Superior
Color
• red skin
Fruit
• clingstone
Afflictions
• Highly resistant to black knot.  Resistant to canker.

AU Rubrum

🔍
Developed in Alabama.
Zone
• 5? (6)     ◦ 700 chill hours
Color
• burgundy skin, red flesh
Fruit
• medium-large size
• clingstone
Afflictions
• Resistant to bacterial canker and bacterial spot.  Somewhat resistant to black knot, brown rot, and leaf scald.

AU Rubrum is one of the better quality AU plums.  Some people like AU Producer as well, but others do not care for it at all.

Black Ice

🔍
? (Oka (P. besseyi) x Z's Blue Giant (P. salicina)) x P. salicina.  Developed in Wisconsin.  PP16621 filed in 2004.
Zone
• 3b? (4a)
Blooms
💮
•    ◦ lacks pollen
Ripens
🍈
• early-mid     ◦ ~1 week before Toka
• biennial
Color
• dark purple skin, red flesh
Growth
• dwarf
Fruit
• medium-size
• semi-freestone
• tart and bitter skin, sweet flesh
Afflictions
• Highly resistant to black knot.  Resistant to bacterial spot and canker.

Multiple reports imply that Black Ice is only hardy down to zone 4a, but people "occasionally" experience severe or completely dieback in warmer areas.  This may be the results of some other kind of vulnerability.

La Crescent

🔍
Shiro (P. Salicina) x Howard Yellow (P. Americana).  non-patented.
Zone
• 3b? (4a)
Blooms
💮
• mid?
Ripens
🍈
• early-mid?
Fruit
• freestone
Afflictions
• Highly resistant to black knot.  Resistant to canker.

A few people have confirmed La Crescent's mild apricot flavor, but it may not be consistent, at least in less than ideal environments.  The flavor "might" be more pronounced when cooked though, but overall, there are better hybrid plums for fresh eating that seem to produce more reliably. 

There are some fairly contradicting reports about La Crescent's bloom and ripening time, but it's probably before Toka by roughly a week or so.

Purple Heart

🔍
Historical information on the 'Purple Heart' plum has been lost.
Zone
• 4
Blooms
💮
• mid
Ripens
🍈
• early-mid
• hangs well
Color
• purple or burgundy skin, red flesh
Fruit
• low acid skin?
Afflictions
• Somewhat resistant to black knot.  Resistant to canker?
Purple Heart may be less susceptible to brown rot than most plums.

South Dakota

🔍
P. americana x unknown.  May be purely Prunus americana.  Developed in South Dakota (early 1900's).  Released in Minnesota (1949).
Zone
• 3
Blooms
💮
• mid?     ◦ extended bloom
Ripens
🍈
• mid-late     ◦ after most american hybrids
Fruit
• freestone
Afflictions
• Highly resistant to black knot.  Resistant to canker.

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     ◦ around Toka
• biennial
• exceedingly precocious
Color
• red skin
Fruit
• medium-large to large in size
• clingstone
Afflictions
• Highly resistant to black knot.  Resistant to canker.

The young branches of Superior may need to be thinned or staked to prevent its precocious nature from breaking them.

Toka

🔍
P. americana x P. simonii.  Developed in South Dakota (1911).
Alias
• Bubblegum
Zone
• 3
Blooms
💮
• mid
Ripens
🍈
• mid     ◦ around late August in some of the most northern parts of the US.
Color
• burgundy skin
Fruit
• small-size
• semi-freestone
Afflictions
• Highly resistant to black knot.  Resistant to canker.

Toka is rumored to be a decent pollinator for other hybrids, but you're generally going to want a pure Prunus americana. 

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.  After a few days on the table, it lost its complex flavor, but it may last longer in the fridge.

Underwood

🔍
Shiro (Asian hybrid) x Wyant (P. Americana).  Developed in Minnesota (1921).  non-patented.
Zone
• 3
Blooms
💮
• early-mid     ◦ extended bloom
Ripens
🍈
• early-mid     ◦ before Purple Heart
Color
• burgundy skin
Fruit
• medium-size
• semi-freestone or clingstone
Afflictions
• Highly resistant to black knot.  Resistant to canker.
Less susceptible to brown rot than most plums.

Waneta

🔍
Apple (P. Salicina) x Terry (P. Americana).  Originated in South Dakota (1913).
Zone
• 3a
Blooms
💮
• mid? (early-mid)
Ripens
🍈
• mid     ◦ around Toka
Color
• burgundy skin
Fruit
• medium-size
• clingstone
• thick tart skin, easy to peel, sweet flesh
Afflictions
• Highly resistant to black knot.  Resistant to canker.

Prunus Cerasifera Hybrid Plums

Cerasifera cherry-plums and their hybrids bloom quite early in the season, but they tend to demonstrate a good amount of resistance to black knot.  Some of them will also develop strong color well before they are ripe, and this can draw the attention of certain kinds of birds and mammals.

Lavina

🔍
P. cerasifera x P. salicina.  Developed in Lithuania.
Zone
• 5? (4)
Blooms
💮
• early
Ripens
🍈
• early-mid
• long harvest season
Color
• red skin
Fruit
• small-size
• freestone, small pit
Afflictions
• Resistant to black knot.
Less susceptible to brown rot than most plums?

Obilnaja

🔍
P. salicina x P. cerasifera.  Originated in Yalta.
Zone
• 5a
Ripens
🍈
• early-mid
Color
• dark purple skin
Fruit
• small-size
• clingstone, small pit
Afflictions
• Resistant to black knot and bacterial spot.
Less susceptible to brown rot than most plums?

Obilnaja plums become well-colored long before they are ripe.

Sprite

🔍
P. cerasifera x P. salicina
Zone
• 4     ◦ 400 chill hours
Blooms
💮
• early
Ripens
🍈
• early-mid
• long harvest season
Color
• dark purple, blue, grey, maroon, or black skin
Growth
• semi-dwarf (8 to 10ft tall)
Fruit
• freestone
Afflictions
• Resistant to black knot.
Highly susceptible to splitting?

Sprite plums become well-colored long before they are ripe.