Most plum species are highly susceptible to plum curculio, a pest that can 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.  In addition to the pests, many varieties are quite susceptible to various forms of disease, 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

varieties in this section generally share these traits (unless stated otherwise)
Susceptible to black knot, brown rot, canker, and splitting.  Blooms later than the other plum species shown here.  Varieties labeled as self-fertile generally need to be cross-pollinated to produce an acceptable crop.  European plums may take a few extra years to produce on most rootstocks (compared to other plum species).

Bavay's Green Gage

🔍
Originated in Belgium
Zone
• 4?
Ripens
🍈
• very late
• can hang for several weeks
Color
• yellow-green skin
Growth
• semi-dwarf
Fruit
• gage-type

Blue Byrd

🔍
non-patented
Zone
• 5
Ripens
🍈
• mid-late
• somewhat precocious?
Color
• dark purple to blue skin
Fruit
• 2" long
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

Castleton

🔍
Valor x Iroquois.  Developed in New York (1993).
Zone
• 4 (3)
Ripens
🍈
• mid (mid-late)
• precocious, hangs well, may ripen asynchronously
Color
• purple or blue skin
Growth
• medium vigor, spreading, heavy spurring
Fruit
• 1.8" H x 1.4" W (4.6cm x 3.6cm), freestone
Afflictions
• Resistant to bacterial spot?

Coe's Golden Drop

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

Count Althann's Gage

🔍
Alias
• Reine Claude Conducta
Zone
• 3b (3a)
Blooms
💮
• late
Ripens
🍈
• mid-late?
Color
• pink-purple skin
Growth
• semi-dwarf
Fruit
• gage-type

Early Laxton

🔍
Zone
• 4
Ripens
🍈
• early?
• one of the first euro plums to ripen
Color
• orange-yellow skin with a heavy red-pink blush
Fruit
• freestone

Empress

🔍
President x Emily
Zone
• 5
Ripens
🍈
• very late
• at least somewhat precocious
Color
• dark purple to blue skin
Fruit
• 2" H x 1.5" W, semi-freestone
Storage
• 2 months

Ersinger

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

Ewing Blue

🔍
Zone
• 4a
Ripens
🍈
• mid? (early-mid)
Color
• dark purple or blue skin
Fruit
• freestone?

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
Blooms
💮
• early?
Ripens
🍈
•    ◦ earlier than other Gage plums
• precocious?
Color
• yellow skin
Fruit
• gage-type

Jubileum

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

Jubileum may not be as biennial as the Victoria plum.

Kenmore

🔍
Zone
• 5
Ripens
🍈
• late
Fruit
• 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?
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 (10-12ft tall)
Fruit
• 50g/fruit, freestone
Afflictions
• Resistant to bacterial spot.

Middleburg

🔍
Ripens
🍈
• very late     ◦ probably later than most others within this category
Color
• blue or dark purple skin
Fruit
• 1.5" x 1.5"

Most zone 5 areas in the US may not have a grow season warm or long enough to properly ripen Middleburg and possibly other very late ripening European plums.

Mirabelle De Nancy

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

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
Growth
• semi-dwarf
Fruit
• freestone or semi-freestone, small pit

Northern Blue

🔍
Mount Royal x open pollination.  Developed in Wyoming.
Zone
• 3?
Ripens
🍈
• contradicting reports (early-mid to mid-late)
• precocious
Color
• blue skin
Growth
• 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 drop when ripe
• precocious?
Color
• burgundy skin
Fruit
• semi-freestone
Afflictions
• Somewhat resistant to plum pox virus?

Oullins Gage

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

Parfume De September

🔍
Ripens
🍈
• late?     ◦ 2 weeks after other Mirabelle plums
Color
• yellow skin
Fruit
• 1" diameter
• 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
Fruit
• 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
Fruit
• gage-type
• freestone, small pit

Reine Claude Doree

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

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.

Rosy Gage

🔍
Imperial Epineuse x unknown
Zone
• 5
Ripens
🍈
• mid-late
• ripen asynchronously
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
• very large
Afflictions
• Resistant to black knot.

Stanley

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

Valor

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

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
• 2" long
• semi-freestone

Vision

🔍
Zone
• 5
Ripens
🍈
• very late
Color
• dark purple skin
Fruit
• 1.5" x 1.5", 55g
• freestone, small pit
Afflictions
• Resistant to bacterial spot.

Asian Plums
Prunus Salicina

varieties in this section generally share these traits (unless stated otherwise)
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, although some have claimed that it develops well 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
Fruit
• 1" diameter
• freestone

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
• 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
• 2.5" diameter
• 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 crisp and crunchy texture as they hang.

Fofonoff

🔍
Developed in Buchanan, Saskatchewan (1973).
Zone
• 2a (1a)
Ripens
🍈
• early-mid?
Color
• yellow skin
Fruit
• clingstone

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
• 2.4" diameter
• freestone, small pit

Ivanovka

🔍
Developed in Morden, Manitoba (1939).
Zone
• 2a
Color
• yellow skin? red blush?
Fruit
• semi-freestone

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
• 2" diameter
• clingstone, small pit
Afflictions
• Susceptible to bacterial spot.

Thinning out excessive fruit production can improve the quality of Ozark Premier.  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     ◦ around Redhaven peach
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
Color
• yellow skin
Fruit
• clingstone
Afflictions
• 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 be superior in flavor when compared to the original Santa Rosa.

North American Hybrid Plums

varieties in this section generally share these traits (unless stated otherwise)
Strong resistance to black knot.  Above average resistance to canker.  Susceptible to splitting.  Blooms relatively late, and may have slightly more resistance against frost damage.  Production issues involving self-sterility, poor pollen production, and genetic incompatibility.  A pure Prunus americana plum is recommended for the pollination of american hybrid plums.  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     ◦ 0 to 1 week after Toka?
Color
• red skin
Fruit
• clingstone

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
• 8.2ft H x 6.6ft W (2.5m x 2m) at the age of nine
Fruit
• 2" diameter
• semi-freestone
• tart skin, sweet flesh
Afflictions
• Resistant to bacterial spot.

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
Fruit
• freestone
Afflictions
• Highly 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 also have some type of vulnerability to cold temperatures or late frosts other hybrids don't seem to share.

La Crescent

🔍
Shiro (P. Salicina) x Howard Yellow (P. Americana).  non-patented.
Zone
• 3b? (4a)
Blooms
💮
• mid?
Ripens
🍈
• early-mid? (early)
Fruit
• freestone

A few people have confirmed La Crescent's mild apricot flavor, but it may not be consistent, at least in less than ideal environments. 

There are some fairly contradicting reports about La Crescent's bloom and ripening time, but it probably ripens a few weeks before Toka.

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.
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

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
• biennial
• exceedingly precocious
Color
• red skin
Fruit
• 2"+, clingstone

The young branches of Superior may need to be thinned or staked to avoid its excessive and early fruit production from breaking them.

Toka

🔍
P. americana x P. simonii.  Developed in South Dakota (1911).
Alias
• Bubblegum
Zone
• 3
Blooms
💮
• mid
Ripens
🍈
• mid     ◦ 1.5 to 2.5 weeks after Redhaven peach (in the northern half of the US)
Color
• burgundy skin
Fruit
• small-size
• semi-freestone

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?     ◦ a few weeks before Toka?
Color
• burgundy skin
Fruit
• medium-size
• semi-freestone or clingstone
Afflictions
• 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
• 1.5 to 2" in diameter
• clingstone
• thick tart skin, easy to peel, sweet flesh

Prunus Cerasifera Hybrid Plums

varieties in this section generally share these traits (unless stated otherwise)
Resistant to black knot.  Blooms quite early in the season.

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
• 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
• freestone, small pit
Afflictions
• Resistant to bacterial spot.
Less susceptible to brown rot than most plums?

Obilnaja becomes well colored long before it fully ripens.

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

Sprite plums are well colored long before they fully ripen.

Southern Hybrid Plums

varieties in this section generally share these traits (unless stated otherwise)
Prunus salicina crossed with North American species.  Resistant to various diseases.  Probably blooms quite early in the season.

AU Roadside

🔍
Color
• burgundy skin, red flesh
Fruit
• medium-large size
• semi-freestone
Afflictions
• Somewhat resistant to brown rot.

AU Rosa

🔍
backcrosses involving Starcher No.  1 (P. angustifolia) and primarily Santa Rosa (P. salicina) or seedlings of the two.
Zone
• 5b (5a)     ◦ 700 chill hours
Ripens
🍈
• early-mid
Color
• burgundy skin
Fruit
• medium-size
• clingstone
Afflictions
• Resistant to brown rot, black knot, bacterial spot, and sun scald.

AU Rubrum

🔍
Zone
•    ◦ 700 chill hours
Color
• burgundy skin, red flesh
Fruit
• medium-large size
• clingstone
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.

Gulf Beauty

🔍
? (contains Ozark Premier, Burbank, Beauty, and Bruce) x Taiwan (Hung-ju x open pollination).  Developed in Florida.  PP11224 (1997).
Zone
•    ◦ 225-250 chill hours
Ripens
🍈
•    ◦ the earliest gulf plum to ripen
• ~2.5 months after pollination in Florida
• can hang for 7-10 days once they are ripe
Color
• burgundy skin
Fruit
• medium to medium-small in size
• clingstone
• tart, slightly bitter skin with sweet flesh
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).
Zone
•    ◦ 250 chill hours
Ripens
🍈
•    ◦ roughly 1 to 2 weeks after Gulf Beauty
Color
• burgundy skin
Fruit
• medium-size
• semi-freestone
• sweet flesh, tart skin
Afflictions
• Very resistant to bacterial canker and fruit scald.  Resistant to bacterial spot and leaf scald.

Gulf Gold

🔍
Developed in Umatilla, Florida.  non-patented.
Zone
•    ◦ 250 chill hours
Blooms
💮
•    ◦ a few days after Gulf Ruby but should overlap with any gulf-series plum
Ripens
🍈
•    ◦ 3 to 4 weeks after Gulf Beauty?
Color
• yellow skin, orange blush
Growth
• semi-dwarf
Afflictions
• Resistant to bacterial canker?
Somewhat susceptible to leaf scald.

Gulf Rose

🔍
Developed in Florida.  PP12833 (2000).
Zone
•    ◦ 275 chill hours
Blooms
💮
•    ◦ a few days after most other gulf-series plums
Ripens
🍈
•    ◦ roughly 2 to 3 weeks after Gulf Beauty
• precocious
Color
• deep burgundy skin and flesh
Fruit
• medium-size
• semi-freestone
• sweet flesh
• slightly tart skin with no bitterness?
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.
Zone
•    ◦ 225 chill hours
Ripens
🍈
•    ◦ roughly 0.5 to 1 week after Gulf Beauty
• can hang for 3-5 days once they are ripe
Color
• red-purple skin
Fruit
• medium-size
• clingstone
• sweet flesh, tart skin
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.