Growing a plum tree from seed is an economical method for propagation. The resultant tree that germinates from the seed will not be a true duplicate of the mother tree. The fruit from which the seed is harvested has been pollinated by other plum trees. According to the North Dakota Extension Service, planting seeds from the plum fruit is easier than attempting to graft stems from the mother tree. In nearly all cases, the plum tree seedling that results from planting a seed will begin to produce fruit five years to seven years after seed planting.
Collect only mature plums that have large amounts of flesh to the fruit. The goal is to harvest seeds from fruits that are free from physical defects and the best example of a plum from the mother tree.
Remove the seed from the plum.
Prepare a planting area for the seeds in well-drained soil that has exposure to full sunlight. The seed planting location must also have good air drainage. In other words, the air must not be hindered by any outbuildings or physical locations that will inhibit air from flowing around the tree. Lack of air movement can cause the early flowering buds of the plum tree to freeze from late spring frosts. Late summer to early fall is the best time to plant plum seeds in the soil.
Work the soil in the seed planting bed to the full depth of the shovel blade. Turn the soil over several times. Remove all rocks and any errant roots from the location.
Plant the plum seed to a 2-inch depth immediately after harvest from the fruit. The plum seed requires stratification in order to properly germinate.
Protect the plum seed from squirrels and other seed predators by placing a piece of hardware cloth over the plum seed planting area. The piece of hardware can be 12 inches square.
Remove the hardware cloth the next spring when the seedling begins to emerge from the ground.