When transplanting a tree, which practice best promotes survival?

• A. Backfill with native soil
• B. Prune the root ball
• C. Apply fertilizer generously directly to the roots
• D. Backfill with a high quality mulch

Answer: (A)

Transplant survival hinges on keeping the new root system in a familiar soil environment and minimizing root disturbance. Backfilling with native soil preserves the soil’s texture, structure, drainage, and microbial life around the roots, helping them reestablish quickly without needing to adapt to a different soil chemistry or moisture regime. This avoids osmotic or nutrient stress that can occur when mixing in foreign soils or soils with different salt levels. Pruning the root ball can remove fine roots essential for water uptake, increasing transplant shock rather than reducing it. Applying fertilizer directly to the roots at planting can burn tender tissue and encourage rapid top growth before roots are ready, hindering establishment. Mulch belongs on the surface to conserve moisture; using high quality mulch as backfill can impede drainage and suffocate roots. In short, sticking with native soil for backfill gives the tree the most compatible environment to recover and grow after transplanting.