Growing a plum tree from the seed found inside the fruit, which is botanically known as a drupe or stone fruit, is entirely possible. This process presents a challenge compared to purchasing a nursery-grown sapling. While a plum pit contains the genetic material needed to grow a tree, the resulting plant requires patience and careful preparation to successfully germinate. The journey from a small seed to a mature tree is a commitment that differs significantly from commercial growing practices.
Understanding the Genetics of Plum Reproduction
The tree that grows from a plum seed will rarely produce fruit identical to the plum you ate, a phenomenon known as not growing “true to type.” Plums are highly heterozygous, meaning they possess a wide mix of different genes from two parent trees. When a seed is produced, it is the result of sexual reproduction, which shuffles the genes and creates a unique genetic individual.
This genetic variability means that the resulting fruit could be smaller, have a different flavor, or even be inedible, as recessive traits for poor quality may express themselves. Commercial orchards avoid this unpredictability by using a technique called grafting, where a cutting from a desirable variety is physically joined to a sturdy root system. A plum grown from seed, however, is often used by growers to develop a strong, disease-resistant root system, which they call a rootstock, for future grafting experiments.
The genetic makeup of the seed-grown tree will determine its mature size and hardiness, potentially resulting in a much taller, more vigorous, and sometimes thornier tree than its cultivated parent. European plums (Prunus domestica) and Japanese plums (Prunus salicina) readily cross-pollinate, creating a diverse genetic lottery in the seed. This unpredictability is why growing a plum from seed is largely an endeavor for hobbyists.
The Essential Step: Stratification and Seed Preparation
The most complex step in growing a plum tree from seed is breaking its natural dormancy, a process called cold stratification. Plum seeds have evolved to prevent germination until they have survived a full winter, ensuring the seedling does not sprout during a temporary warm spell. To begin, you must first clean the pit thoroughly to remove all residual fruit pulp, as this sugar residue encourages mold growth during storage.
For better germination success, the hard outer shell of the pit can be gently cracked open to extract the inner seed, taking care not to damage the soft kernel inside. This step bypasses the natural mechanical barrier of the pit. The seed then requires a period of cold and moisture to simulate the winter environment it needs to “wake up.”
The most reliable method is to place the cleaned seeds in a plastic bag filled with a moist medium like peat moss, vermiculite, or damp paper towels. Store this bag in a refrigerator at a consistent temperature between 34 and 40 degrees Fahrenheit (1 to 5 degrees Celsius). The cold stratification period must last for a minimum of 60 to 90 days to effectively break the seed’s dormancy. Throughout this time, monitor the seeds regularly to ensure the medium remains moist and check for any signs of mold.
Planting, Growth, and Long-Term Expectations
Once the cold stratification period is complete, you will often see the seed beginning to sprout a small root, indicating it is ready for planting. The ideal time to plant your sprouted seed is in the spring, after the danger of the last hard frost has passed. Select a location that receives full sun for at least six hours daily and has well-draining soil, as plum trees do not tolerate standing water.
Plant the seed about one to three inches deep in a small container or directly into its permanent spot if the weather permits. The soil should be kept consistently moist but never waterlogged during the initial growth phase to support the developing root system. You can also apply a light layer of mulch around the base of the seedling to help retain soil moisture and regulate temperature.
Be prepared for a long wait before you see any fruit, as a plum tree grown from seed requires a juvenile period to fully mature. While grafted trees may produce fruit in just two to four years, a seed-grown plum tree typically takes between five and ten years to reach fruiting maturity. During the first year, protect the delicate seedling from pests and ensure it receives consistent water, which promotes vigorous growth and helps it establish a strong foundational structure.