The stages of growth progression in apple trees are consistent every year. The timing and appearance of each stage may be different because of the weather conditions, but once the trees come out of dormancy they display the same stages of growth progression every season.
The last post discussed the “silver tip” stage of development in the progression of the apple tree as it comes out of dormancy and prepares itself for the new fruit year. Following “silver tip” is what is commonly known as “green tip.” “Green tip” is basically self explanatory. The buds are broken at the tip and about 1/16th of an inch of green tissue becomes visible. The next stage is “half inch green” or “centimeter green.” Again pretty simple to explain as the bud has about 1/2 inch of green tissue emerging. Following “half inch green” is noted as “tight cluster.” The blossom buds are mostly exposed in the “tight cluster” stage. The buds are closely grouped (tight) together and have short stems. Following “tight cluster” the trees are considered “pink.” Sometimes this stage is also referred to as “open cluster.” The fruit buds open into bloom and the clusters of blooms are pink in color. The stems of the buds are lengthened.
“Full pink” or “open cluster” is when the King Bloom appears. Usually there is a cluster of six buds. Five of these buds are centered around a central blossom known as the King Blossom. The King Bloom is the first to open and good fruit set is insured if this King Bloom is pollinated. The fruit of this pollinated King Blossom is often larger than the others in the cluster.
When the apple trees are in the stage of the “King Bloom” the weather plays a vital role in the outcome of the fruit and thus, the future harvest. Pollination of the blossoms is dependent on favorable conditions. Bees need sunny days and warm temperatures to go about their work in pollinating. Also the blooms are very susceptible to cold temperatures. Frost and below freezing temperatures can heavily damage or destroy the blooms. This week the prediction calls for frost and lower then freezing temperatures in our region. Thus, we plan to keep a close watch on our thermometers.