Madeline Wimmer- UMN Fruit Production Extension Educator This fruit update contains information about… Apples Growth stage update: pink- bloom. Considerations for fruit thinning during bloom Grapes Growth stage update: Early-season shoot thinning. Raspberries Raspberry cane diseases Honeyberries Growth stage update: bloom, and pollination compatibility Apples Images: (Left) Pink is the growth stage that occurs right before bloom, in apples. Here shows an apple bud in late-pink. (Right) Apples begin to bloom with one main flower, known as the king flower, emerging into full bloom before other blossoms. Photos taken at ApplesRus Orchard in Olmsted County (Zone 5a, 05/05/25). Growth stage update: Pink - King bloom. Pink! Is the apple landmark growth stage following tight cluster. This is the phase where the apple floral buds are continuing to develop, while surrounding leaves grow larger in size. Pink is the sign that bloom is just around the corner, which indicates the need to start thin...
Article written by Madeline Wimmer, UMN Extension Fruit Production Educator. Images: King blossoms are the first apple blossoms to open and generally produce the highest quality fruit. Their early timing is key to bloom thinning strategies that rely on pollen tube growth models. Photos taken at ApplesRus in Olmsted County, Minnesota (Zone 5a). Apples benefit from fruit thinning. The first step to managing an apple’s crop load each year starts with dormant pruning. While pruning helps to reduce the total number of fruiting spurs, apples still produce more blossom/fruits per fruit spur than is ideal. This is in part because densely clustered apples increase the chance for development of fruit rot later as moisture can become trapped between large apples. Apples with shorter stems can additionally put pressure on one another, leading to increased drops before harvest. Biennial bearing is another condition some apple trees are also prone to that can be relieved with thinning pr...