Plum Fruit Guide | The Green Urban Lunch Box

Soft, plump stone fruits. Can range in color from yellow to red to purple to blue to green. Plums are round or oval in shape and are about the size of a golf ball or smaller.

How to Care for Plum Trees

Pruning

Annually prune both immature and mature plum trees in spring to remove dead and damaged material, water spouts and suckers, and to maintain desired shape and size. Amount of pruning necessary varies by type of plum—Japanese and American varieties require more pruning than European varieties. We offer fruit tree pruning January through March in Salt Lake County.

Fertilizing

Fertilize yearly in the spring when the trees are in bloom. We offer compost tea fertilizing for fruit trees and gardens. Compost tea has many benefits, some of which are improved plant growth and increased nutrient retention.

Thinning

The necessity of thinning will vary from season to season, as well as among different varieties of plums. A good rule of thumb is to thin plums when they are between dime and quarter sized. Japanese plums should have about 5 inches of space between each fruit, while European plums should be thinned to 2-4 inches. We offer fruit tree thinning in April and May in Salt Lake County.

Watering

Young trees need extra water to grow, while all fruit trees need additional water during periods of hot, dry weather—much like those we experience on the Wasatch Front in the warmer months. Thoroughly soak the soil around your fruit trees every other week. Mulching around the base of your tree can help retain soil moisture as well.

Harvesting

Plums will ripen off of the tree, but will have better flavor if picked closer to being ripe.

Plums are ready to be harvested when…

Skin changes color from green to yellow, red, purple, blue, or black. Greengage plums remain green, but may develop yellow highlights when ripe.

Flesh will be soft (but not squishy, which would indicate it is overripe).

Fruit pulls easily from branch.

Schedule a Harvest with Us!

A good time to schedule is when the plums have changed color, are slightly soft, and pull easily from the branch. Because there are so many varieties of plums, it is hard to estimate when particular plums may be ripe. We may be booked up to three weeks out, so monitor your fruit throughout the summer and fall for signs to ensure that it is harvested at the proper time! We can’t harvest if…

The load is too low. Must be at least 150 lbs of fruit.
The fruit is overripe. Fruit must not be too ripe to withstand picking, stacking in bins, and transporting to donation and distribution sites.
The fruit is far too underripe. Plums will ripen a bit off of the tree, but will have better flavor if picked closer to being ripe.

Disease & Pest Control

Plums do not experience a high risk of disease or pests in the arid regions of the western United States. For information on low-risk diseases and pests that may impact your plum tree, click here.

Storage Tips

Unripe plums can ripen on the counter or in a paper bag. Ripe plums should be refrigerated, but will not ripen in there.
Plums can also be canned, frozen, or dried.

Other Plum Information

There are three main groups of plum varieties – European, Japanese, and American. The groups vary in their size, shape, color, flavor, and their uses.

Plums prefer light, well-drained soil. In wet and heavy soils, plums may experience root-rotting.

Plums in Utah are also prone to developing iron chlorosis, the risk of which is significantly increased by overwatering.

Check out our other Fruit Guides!

Other Resources:

Check out our other Fruit Guides!

Other Resources:

USU Extension
Not Far From the Tree
The Fruit Gardener’s Bible, Hill & Perry (2011)

Join the volunteer team!

We love our volunteers and would love to have you join us! There are many ways you can volunteer–from picking fruit to helping in a garden to sitting on a committee.