Cultivating your own plums, moving from a simple sapling to a tree heavy with fruit, is a rewarding experience. Not every plum tree is suited for every location or garden, requiring informed decisions before purchase. Success depends on understanding the foundational needs of a plum tree and sourcing a healthy specimen. The initial selection must focus on horticultural compatibility and the physical quality of the tree itself.
Essential Horticultural Considerations Before Shopping
A successful plum harvest begins with selecting a variety compatible with your local climate, tied to both USDA Hardiness Zones and chill hours. Hardiness Zones indicate the minimum winter temperature a tree can tolerate, generally placing plums in the range of USDA Zones 4-9. Plum trees also require a specific number of “chill hours,” the cumulative hours between 32°F and 45°F during winter dormancy, to properly set fruit in spring. European plums typically need 700-1,000+ chill hours, while some Japanese varieties require as few as 150-600 hours.
Plum varieties fall into two main types: European plums (Prunus domestica) and Japanese plums (Prunus salicina). European types, including prune plums and gages, are generally hardier, bloom later, and are often self-fertile, meaning a single tree can produce fruit. Japanese varieties bloom earlier, making them more susceptible to late frosts. They are known for their juicier, firmer fruit but often require a second, compatible variety for cross-pollination to ensure a good crop.
The physical size of your future tree is determined by the rootstock, the underground portion onto which the desired plum variety is grafted. Rootstocks like Myrobalan 29-C produce a standard-sized, vigorous tree, while St. Julian A or Krymsk 1 result in semi-dwarf or dwarf trees, respectively. Beyond size control, the rootstock also imparts tolerance to certain soil conditions, such as wet or heavy clay soils, and resistance to specific soil-borne pests and diseases. Selecting a rootstock that thrives in your native soil composition is as important as choosing the right plum cultivar for the climate.
Reliable Vendor Types for Plum Trees
The source of your plum tree directly influences its quality, the variety selection available, and the level of expert advice you receive. Local independent nurseries are often the best source for stock acclimatized to your specific microclimate. They offer personalized advice from staff who understand regional soil types and pest pressures, though their selection of specialized cultivars may be limited, and prices are often higher.
Specialty online or mail-order nurseries provide the widest selection of plum cultivars and rootstocks, including unique or heirloom varieties not found locally. These vendors ship bare-root stock during the dormant season, which is more economical and establishes quickly, but requires prompt planting upon arrival. While quality from reputable mail-order nurseries is high, the tree is subject to shipping stress, and you cannot inspect the physical tree before it arrives.
Big box stores and large garden centers offer the convenience of immediate availability, often with pre-potted container trees. However, the variety selection is usually limited to common types, and the trees may have been grown in conditions that lead to issues like pot-bound, circling roots. The lack of horticultural expertise among staff can make it difficult to get specific advice on rootstock or pollination requirements.
What Makes a Healthy Plum Tree Purchase
Plum trees are purchased either as bare-root stock during winter dormancy or as containerized stock available throughout the growing season. Bare-root trees are shipped with no soil around the roots, offering the advantage of a full inspection of the root system. Containerized trees are easier to handle and plant, but require careful inspection to ensure they have not been growing in the pot for too long.
For containerized trees, assess root health by gently pulling the tree out of its pot. A healthy root system has firm, white root tips, but look for signs of girdling roots—thick roots circling the inside perimeter of the pot. Girdling roots must be avoided as they will choke the tree’s vascular system; bare-root stock should have numerous, pliable, and moist roots that are evenly distributed.
The trunk and branches also require scrutiny. A quality plum tree should have a strong central leader and an absence of mechanical damage, which can serve as entry points for disease. Avoid trees that show signs of fungal infection or pest damage, such as unusual oozing sap (gummosis) or visible cankers on the bark.
Finally, examine the graft union, the slightly swollen area where the plum variety (scion) meets the rootstock, usually located a few inches above the soil line. This union should be well-healed, solid, and free from cracks or excessive swelling. Ensure the plum variety is growing robustly above this union, and that no shoots or suckers are emerging from the rootstock below the graft, as these will grow into the undesirable rootstock variety.