All-purpose organic fertilizer might be important to encourage healthy development; however, there are a couple of interesting points. To begin with, consistently test your soil to ensure you pick the right fertilizer, if any, required. Over-fertilizing can cause undesirable growth and decrease the amount of fruit production. In the first year of planting a new plum tree, fertilize once in the early spring before the leaves show up. Then, fertilize twice in the second year, once in the early spring, and afterward again in early autumn.