Avoid heavy pruning until the tree begins bearing fruit (usually 3–5 years).
Based on the search results, "Big Tree Plum" appears to refer to the ( Prunus nigra ), often called a wild plum or sometimes sloes. These hardy, native trees grow in eastern North America, offering dark-colored branches and plums that vary in color (red, orange, or yellow). Quick Guide: Canadian Plum ( Prunus nigra ) Plant Zones: 1-7 (Very cold hardy) big-tree plum
Requires a second variety (another wild plum seedling) 1. Planting and Site Selection Avoid heavy pruning until the tree begins bearing
Water heavily every week during the first growing season to establish roots. Quick Guide: Canadian Plum ( Prunus nigra )
Because they flower early, avoid planting in low "frost pockets" where cold air settles. Plant on a slope or near a building for protection. 2. Care and Maintenance
Protect young trunks with wire cages (deer) or hardware cloth (voles) to prevent girdling. 6. Harvesting Timing: Fruit matures in late summer to early fall.