The Jefferson Plum is a classic variety celebrated for its exceptional flavor and versatility. Its reliable production and quality fruit make it a favored choice for home orchards.
Understanding the Jefferson Plum
Originating in Albany, New York, around 1825, the Jefferson Plum is believed to be a seedling of the Coe’s Golden Drop plum. This variety produces medium, round-oval fruits with a dull green-yellow skin, often accented with a pinkish-red flush and subtle bronze markings. A thin, powdery white bloom typically covers the surface.
The golden-yellow flesh is juicy, meaty, and firm, with a small, easily removed freestone pit. This plum is renowned for its rich, sweet flavor, often described as full-tasting with a hint of sharpness. Trees are known for good disease resistance and reliably produce fruit ripening over an extended period of about ten days.
Cultivating Jefferson Plums
Successful cultivation of Jefferson Plums requires careful attention to siting, planting, and ongoing care. Meeting their specific requirements makes them a rewarding addition to a home garden.
Site Selection and Soil
Selecting an appropriate planting site is important for the Jefferson Plum. It thrives in full sun, requiring a minimum of six to eight hours of direct sunlight daily for proper fruit development and flavor. A south-facing or sheltered location with ample sun exposure is often ideal.
The tree performs best in well-drained, fertile soil, ranging from sandy loam to sandy clay loam. Avoid areas with heavy clay or poor drainage, as waterlogged conditions can be detrimental. An optimal soil pH range for Jefferson Plums is between 6.0 and 6.5.
Planting Your Plum Tree
Planting should occur during the dormant season, ideally early winter, to allow the tree to establish before spring growth. When preparing the planting hole, amend poor soil with organic matter like compost to improve its structure and fertility. Space trees approximately 18 to 22 feet apart for mature growth and air circulation.
Do not add commercial fertilizer directly into the planting hole, as it can harm newly planted roots. Wait until the spring following planting to begin fertilization. Initial care involves consistent watering to help the tree settle.
Watering and Fertilizing
During its first growing season, a newly planted Jefferson Plum benefits from weekly watering to establish a strong root system. Once established, deep watering every seven to ten days is necessary during dry periods, especially when rainfall is insufficient. Avoid overwatering, as soil that remains too wet can lead to root issues; slightly drier soil conditions are generally preferable.
Fertilization depends on soil nutrient levels. If the soil is rich, no fertilizer may be needed until the tree bears fruit. For lower fertility soils, apply a balanced, all-purpose fertilizer in spring after planting, following bud break. Avoid fertilizing after July 1st, as late applications can stimulate new growth vulnerable to early frosts. Young trees can receive about one cup of 10-10-10 fertilizer over a three-foot area in early spring. Mature trees can be fertilized twice annually, in early March and around August 1st, adjusting quantity based on the tree’s age.
Pollination Requirements
The Jefferson Plum is not self-fertile and requires a compatible cross-pollinator to produce fruit. Successful fruit set depends on pollen transfer from another suitable plum variety that blooms at a similar time. Planting a compatible pollinator nearby is essential for fruit production.
Several plum varieties are effective cross-pollinators for the Jefferson Plum:
- Czar
- Denniston’s Superb
- Victoria
- Opal
These varieties belong to compatible pollination groups, ensuring effective pollen exchange during the blooming period.
Pruning for Health and Production
Pruning maintains the health and productivity of Jefferson Plum trees. The most suitable time is late spring or early summer, which helps avoid fungal infections like silverleaf disease. Regular pruning also involves removing water sprouts, vigorous upright shoots that do not contribute to fruit production.
Thinning the fruit improves the quality of remaining plums. When fruits are about the size of a dime, thinning allows them to grow larger and develop full flavor. This also helps prevent limb breakage from an excessive fruit load. Strategic pruning cuts can spread the tree’s canopy, allowing better sunlight penetration and air circulation.
Common Pests and Diseases
While generally disease-resistant, Jefferson Plum trees can be susceptible to common pests and diseases. Aphids are a frequent concern, causing leaves to curl and become sticky, which can stunt growth. Other pests include plum moth (infesting fruit), plum curculio (damaging developing plums), spider mites, and Japanese beetles (affecting foliage and fruit).
Common diseases include brown rot (a fungal issue affecting fruit), leaf curl (impacting young leaves), black knot (swollen galls on branches), and bacterial canker (causing dieback). To manage these issues, encourage natural predators for pests like aphids. Applying insecticidal soap or neem oil can help control infestations. Proper watering and good air circulation through consistent pruning also contribute to overall tree health and disease prevention.
Harvesting and Enjoying Jefferson Plums
Harvesting Jefferson Plums at the right time ensures optimal flavor and quality. They typically ripen mid to late August or early September, though timing varies by climate. The fruit ripens over an extended period, often lasting about ten days, allowing for a staggered harvest.
To determine ripeness, look for golden-yellow skin with a developing pinkish-red flush, indicating maturity. The plum should feel slightly soft to the touch, yielding gently when pressed. A ripe Jefferson Plum will also detach easily from the stem with a gentle twist or upward push; if it resists, it needs more time on the tree. Ripe plums will exude a sweet, fruity aroma and possess their characteristic juicy, flavorful flesh.
Once harvested, Jefferson Plums are excellent for fresh eating, offering a rich, sweet experience directly from the tree. Their freestone nature, where the pit easily separates from the flesh, makes them convenient for various uses. They are also well-suited for culinary applications, including jams, jellies, preserves, baked goods, or canning.