Cherry Trees

Cherry trees — both sweet (Prunus avium) and sour (Prunus cerasus) — are moderate feeders among fruit trees, requiring careful nitrogen management because they are more sensitive to over-fertilization than apples or peaches. The primary diagnostic for nitrogen needs is annual shoot growth measurement: cherry trees should produce 12-18 inches of new terminal growth per year, and the fertilization rate should be adjusted up or down based on this observation rather than following a fixed schedule. Colorado State Extension recommends cherries receive 0.4 pounds more nitrogen per 1,000 square feet than apples and pears, reflecting their slightly higher demand, yet excess nitrogen causes exactly the same problems as in other stone fruit — excessive vegetative growth (water sprouts), reduced fruit color, delayed maturity, and increased susceptibility to bacterial canker and winter injury. Sweet cherries are notoriously difficult in New England due to their sensitivity to late spring frosts, rain-induced fruit cracking, and bacterial canker, while sour cherries (like Montmorency and North Star) are far more cold-hardy and forgiving. The critical nutritional period begins at bloom when the tree transitions from using stored reserves to actively absorbing soil nutrients. Calcium is essential for fruit quality and tree cold hardiness in northern climates, while zinc deficiency is common in alkaline soils and requires dormant foliar spray rather than soil application for effective correction. Stone fruit trees should only be fertilized when they set a crop the previous year — unfertilized trees that lost their crop to frost performed just as well as fertilized trees in Penn State research.