Ever wondered what the difference is between a plum and a prune? Prunes are plums, but just dried so that they will keep longer, and they fall into the European category of plums. Their higher sugar content is what makes them better for sun-drying
Plums come in multiple skin colors - red, yellow, purple, green, blue, and almost black. Once you bite into them, many times their sweet interior flesh can be a different color, either red, yellow or green. The two dominant classifications of plums, European and Japanese, include all these colors and a variety of shapes.
European plums bloom later than Japanese types and therefore have some natural hardiness that makes them more adapted to colder climates with late frosts and cool, rainy spring weather. Their need for a higher chill during winter excludes them from most very mild winter areas. Many Japanese and European varieties are self-fruitful, but others need a pollinator. Keep in mind that European plums need a European pollinator and Japanese plums need a Japanese pollinator; they won’t pollinate each other. Both types of plums grow to about 15 feet tall with a 10-12 foot spread, and there is no reliable dwarfing rootstock available for them.
Japanese plums tend to produce larger and juicier fruits, with a pleasant blend of sweet and acidic flavor that makes them perfect for fresh eating. European plums have a firmer flesh and can be eaten fresh or cooked. A few varieties are best for making prunes (like Stanley or Italian) and are used mostly dried or canned, but can also be eaten fresh.
Location
Open site in full sun, with good air circulation. Plums do best in landscape or garden locations but can also do well in lawns. Just be aware that you may have to pick up a lot of fruit before playing soccer in the back yard when harvest season is on. Plan on planting trees 15-20 feet apart for good spacing.
Soil
Deep garden, loamy soil works best - well drained, not soggy. Avoid heavy clay or overly sandy soils. Plums are vigorous growers, and can handle various soil types better than other trees in the Prunus family.
Planting
See bare root and container planting guides
Water
To ensure steady fruit development from bloom to harvest, make sure to provide regular water throughout the growing season - usually a deep watering every 5-10 days depending on heat and sun exposure. As the fruit begins to ripen and approach harvest, cut back on watering to prevent fruit splitting.
Fertilizer
Use a balanced fertilizer in early spring with micronutrients to maintain consistent growth and fruit production. We recommend Anderson’s Best: That’s All It Takes, Fertilome Fruit, Nut and Pecan food, or Natural Guard Organic Fruit and Citrus Fertilizer. A good rule of thumb is to use 1/2 to 1 pound of fertilizer per inch of trunk diameter (2 cups generally equals 1 pound). Spread fertilizer evenly around the drip line of the tree.
Pruning
Some orchard arborists suggest that Japanese Plums be pruned to an open vase shape because of their vigorous lateral growth, and European be trained into a central leader since they don’t branch as freely. Once the trees have matured and have been trained into their favored shapes, they require minimal pruning each season. Each year remove any damaged or diseased branches. This can be done any time after bloom or during dormant season. Each spring, take out any non-productive shoots. Japanese plums may need a little more severe pruning to remove excess growth. Rarely do European plums need thinning, unless the tree has produced an unusual amount of fruit. Japanese plums mature best if thinned to 4-6 inches apart early on in the season, usually just as the fruit starts to form. Also, see our pruning guide for more pruning instructions for stone fruits.
Harvest and Yield
When harvesting, pick the fruit when it has colored up and has softened slightly. Plums ripen mid-summer through fall, depending on variety. Each tree will usually produce 60-100 pounds of fruit depending on location, fertilizer, variety and rootstock.
Pests
Aphids love to attack plum trees each summer. To best control the aphids, use a dormant spray/fungicide combo during the late dormant season or even just as the buds start to swell in early spring. During the growing season (even right up until harvest), apply a general-purpose insecticide as needed. Fertilome Fruit Tree Spray (organic), Sevin, or Malathion are all excellent insecticides for the job. Lady Bugs will also do a great job at controlling aphid outbreaks.
Peach Tree Borer also consistently attack plum trees. Watch for small holes in the trunk, especially near the base, with sap oozing from the holes from early spring to mid-summer. Borers target stressed or damaged trees, and disrupt the sap flow through the tree by damaging the tissue right under the bark that transports water and nutrient to all parts of the tree. Their damage can severely harm the tree, causing leaf and branch dieback, and eventually kill the entire tree. We recommend an application of Permethrin to the trunk and crotches of the lower branches during the dormant season, and then once in late May, and again in early July to control the adults as they emerge from the trees and begin laying eggs for the next generation.
Blossom blight, shot-hole fungus, and brown rot are some of the most common diseases that affect plums. Prevent disease by starting the season with a dormant spray/fungicide combination. Next, apply a general-purpose fungicide right after blossom drop. To prevent shot-hole fungus and blossom blight, continue to apply fungicide every 2 weeks during the cool, wet season of spring. It is essential to spray again in the fall, at about 25% leaf drop to stop these harmful diseases from permanently damaging your trees. For a good general-
purpose fungicide, we recommend Copper Soap, F-Stop by Fertilome or Complete Disease Control from Monterey.
Varieties
Damson
They are round to oblong in shape and have smooth, shiny, deep purple to black skin. The firm amber flesh is very tasty with a spicy, tart flavor. Damson is especially popular for jams. This hardy tree us largely untroubled by pests or diseases and will often thrive where other plums won’t. They are partial-shade tolerant and heavy producers especially when not fully exposed to the elements.
Mature Height: 12’-18’
Mature Spread: 10’-18’
Sun Exposure: Full
Flavor: Sweet flesh; tart skin
Cooking/Storage: Great for both; very popular for jams.
Bloom Period: Early April
Pollinator Required: No
Harvest Period: August
Zones: 5-9
Elephant Heart
This fantastic plum boasts very large, heart-shaped fruits often twice the size of a golf ball. The flesh is a beautiful, rich, blood-red with an exceptional flavor. Under good conditions they can produce as early as three years after being planted. It’s sweet, juicy flesh make it good for eating, canning, juice, and freezing. This is a good pollinizer for other Japanese plums.
Mature Height: 12’-18’
Mature Spread: 10’-18’
Sun Exposure: Full
Flavor: Sweet and rich
Cooking/Storage: Fresh-eating and storage.
Bloom Period: Early to Mid-Spring
Pollinator Required: Recommended, but may produce some on its own
Harvest Period: August - September
Zones: 5-9
Green Gage
The Green Gage is a very popular old fashioned English plum that grows well over a wide range of climates. It is self-fertile tree that ripens early in the season so you can begin enjoying your plums right away. This plum is very sweet, yellow flesh is surrounded by a yellow-green skin that turns yellow when ripe. Green Gage is said to be one of the best flavored plums available.
Mature Height: 12’-18’
Mature Spread: 10’-18’
Sun Exposure: Full
Flavor: Very sweet and juicy
Cooking/Storage: Fantastic fresh or processed.
Bloom Period: Early to Mid-Spring
Pollinator Required: No
Harvest Period: July
Zones: 5-9
Italian Prune
The Italian Prune is a sweet, small to medium-sized plum with yellow flesh and deep, purple skin. It is given the name “prune” because it is particularly good for drying while still great for canning and fresh eating. This tree often overbears and will need thinning early on for good-sized fruit. The trees prefer full sunlight and moist, well-draining soil.
Mature Height: 12’-18’
Mature Spread: 10’-18’
Sun Exposure: Full
Flavor: Sweet
Cooking/Storage: Good fresh, processed, cooked, or dried
Bloom Period: Mid-Spring
Pollinator Required: No
Harvest Period: Early-September
Zones: 5b-9
Santa Rosa
Santa Rosa is a firm, good quality fruit. It has beautiful red flesh with a purplish-red skin. It has a sweet, delicious flavor and is one of the most widely planted Japanese plums. This is a self-fertile tree so it’s great for areas with little room for extra trees. The fruit will be firm to slightly soft with a smooth skin. It’s good for cooking, canning, processing, fresh eating, and even freezing. It is still the standard for flavor plums.
Mature Height: 12’-18’
Mature Spread: 10’-18’
Sun Exposure: Sun
Flavor: Sweet, fragrant
Cooking/Storage: Good for both.
Bloom Period: Mid-Season
Pollinator Required: No
Harvest Period: Late-July
Zones: 5-9
Satsuma
An excellent choice for fresh eating, cooking, canning, and jam. Heavy bearing tree with a horizontal spreading growth habit making it good for the narrow spaces. It is a large Japanese variety with beautiful, solid-red flesh and red, mottled skin. The juicy flesh has a lovely, sweet flavor and a small pit. It is productive and consistent producer when it has a pollinator.
Mature Height: 12’-18’
Mature Spread: 10’-18’
Sun Exposure: Full
Flavor: Sweet, no tartness
Cooking/Storage: Good for all.
Bloom Period: Early to Mid-Spring
Pollinator Required: Yes
Harvest Period: Early-August
Zones: 5-8
Stanley Prune
Sweet enough to dry without being pitted. European freestone bears huge crops of plump, dark blue fruits golden flesh. Its flavor is very sweet with juicy flesh. The plums are an excellent quality suited for fresh eating, canning, preserves and drying. Like other European plums it is self-fertile and will set good crops on its own, but will produce even more with another plum nearby.
Mature Height: 12’-18’
Mature Spread: 10’-18’
Sun Exposure: Full
Flavor: Sweet
Cooking/Storage: Good for all.
Bloom Period: May
Pollinator Required: No
Harvest Period: September
Zones: 5-8
Superior Hybrid
Fast-growing clingstone bears red-blushed crimson fruits bursting with super-sweet yellow flesh. Dessert plum also ideal for eating fresh off the tree.
Mature Height: 12’-15’
Mature Spread: 12’-15’
Sun Exposure: Full sun
Flavor: Sweet
Cooking/Storage: Good for cooking.
Bloom Period: Mid-Season
Pollinator Required: Yes
Harvest Period: August
Zones: 4-8