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Plums: A Guide to Selection and Use

by Richard C. Funt    

Plums are an excellent tree fruit that can be used in many ways for snacks and family meals. The fruit is suitable for canning, freezing and preserving into jams and jellies. The trees are hardy and if given reasonable care, can be expected to grow and produce well under Ohio growing conditions.

Types of Plums

Plums are of three different types belonging to the European, Damson and Japanese groups. Of the three groups, the European types are most satisfactory for Ohio conditions. Familiar varieties of the European type are Stanley, Reine Claude (Green Gage) and the French and German prune (Fellenburg) types. The European-type plums are best for eating out-of-hand and for canning.

The Damson type plums also grow well in Ohio, but because the fruit is very tart, the plums are used chiefly for cooking and preserve making. Examples of Damson-type plums are Shropshire and French Damson.

The Japanese-type plums are generally not satisfactory in Ohio. The primary reason for this is the frequent loss of crops due to poor pollination and spring-frost injury when the trees bloom early in the spring.

Examples of Japanese-type plums are Methley, Shiro, Ozark Premier, Burbank and Elephant Heart.

Selecting Plums for Consumption and Nursery Stock for Planting

For Consumption

High quality plums are firm and free from defects such as bruising and insect and disease damage, and they are well shaped and colored. Without a good knowledge of plum cultivar (variety) characteristics, it is difficult to detect when a plum is ripe by color alone. This is because of the many different colors in which the fruits may occur. Plums may be various shades of red, blue, green and yellow. The best guide to plum ripeness is to apply gentle pressure to the fruit with the thumb and determine if the flesh is beginning to soften. If so, the fruit should be ready for consumption. If not, allow the fruit to ripen for a day or so at room temperature. Prevent the plums from becoming overripe as the eating enjoyment will be reduced because of changes in flesh consistency and flavor. Ripe plums should be stored in the refrigerator to prevent rapid deterioration.

For Planting

An important consideration in selecting plum cultivars for planting is that of pollination requirement. Trees of some plum cultivars are capable of setting and producing a crop if grown as single isolated plants. Other plum varieties that are self-unfruitful require cross pollination for fruit set and development. This means that trees of at least two cultivars with overlapping bloom periods must be planted.

Some suitable cultivars for planting include Stanley, Bluefre, Vision, Italian Prune and Reine Claude (Green Gage). Stanley is self-fruitful. The others require cross pollination for best results. Standard plum trees usually begin to bear fruit three to five years from planting. The trees have a useful life of 15 to 20 years and come into full production in about 10 years. Yields of 3 to 5 bushels per tree may be expected, depending on cultivar.

Nursery Stock

Desirable nursery stock for planting consists of trees 3 to 6 feet tall with a trunk diameter of 3/8 to 3/4 inch.

Plum trees should be planted in early spring. Standard-size plum trees should be spaced at least 20 feet apart in fertile, well-drained soil.

Cultural Practices

Important cultural practices in plum production are pruning and training, fertilizing, mulching, and pest control.

Plum trees of the European type are best pruned and trained to the modified central leader system. In this system, several well spaced side or lateral branches (scaffolds) are allowed to develop from the main trunk or leader of the tree. When the tree reaches the desired height, the central leader is cut to a short lateral branch.

Plum trees should be fertilized annually for best growth and development. Suggested fertilizer practice is an early spring application of 1/20 pound of actual nitrogen (8 ounces of 10-10-10) fertilizer per year for each year of tree age.

Mulching with an organic mulch such as straw, sawdust, wood chips and similar materials can help conserve valuable soil moisture and help control weeds under the tree. Common pests and diseases of plum trees include plum curculio, European red mite, brown rot, leaf spot and black knot. Contact your local Extension office for current control recommendations.

Harvesting and Storing

The recommended cultivars ripen in September in central Ohio. Color changes are particularly noticeable as plums approach maturity; consequently, color is a most useful guide to the harvest time for plums.

As color develops there is usually a softening of the flesh. With experience with a particular variety, one can soon correlate color with taste and judge when the fruit should be harvested from the tree.

Ideal storage conditions for plums consist of maintaining a temperature of 31 to 32 degrees F and a 90 to 95 percent relative humidity. Under such conditions, storage life of plums is from two to four weeks. For many, the home refrigerator will be the best method of preserving the after-harvest life of the fruit until it is consumed or preserved.

For additional information about growing fruit, obtain a copy from your County Agent of Bulletin 591, Growing and Using Fruit at Home and Bulletin 528, Training and Pruning Fruit Trees.

Originally prepared by James D. Utzinger, Extension Horticulturist, The Ohio State University.


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