Q: My father and I are planting a bare root Stella cherry tree. I have read that we should add nitrogen when planting but in winter? What would you recommend?
A: Your instincts are exactly right. There is no absolute need to add fertilizer when planting a tree, no matter the season. I am aware that there are “starter” fertilizer products available. Most contain a slow release form of nitrogen and a high percentage of phosphorus as ingredients. It is possible the phosphorus might help new trees in situations where there is none present. But almost all nitrogen that is applied will be wasted, since the tree cannot absorb it in cold soil. Research has shown that mulching a newly planted tree with three inches of arborist woodchips is an excellent post-planting treatment. The chips prevent weeds, control soil moisture, and slowly release nutrients as they decompose.