Cherries are a type of fruit characterized by a fleshy exterior surrounding a hard pit. Their development from a dormant bud to a ripe, harvestable fruit is a complex journey influenced by genetic programming and environmental cues.
From Bud to Blossom
A cherry’s annual cycle begins with emergence from dormancy, a state often broken by cold temperatures known as chill hours. Once sufficient chill has accumulated, typically 700 to 1,000 hours below 45°F (7°C), warmer temperatures in late winter or early spring signal bud development. The buds first swell, transitioning from a dormant, tight state to a visibly expanded form.
Following bud swell, the “green tip” stage appears, showing the first hint of green tissue. This progresses to the “popcorn” stage, named for the small, round, white flower buds resembling popcorn kernels. Full bloom occurs when the majority of flowers on the tree are open. This period of open flowers is when pollination, primarily by bees, becomes possible, which sets the stage for fruit development.
Initial Fruit Formation
After successful pollination and fertilization, the flower transforms, marking the beginning of fruit set. The ovule inside the flower develops into a tiny, green fruit. Following fruit set, rapid cell division and expansion cause the newly formed cherries to quickly increase in size.
During this early growth phase, the fruit remains small, firm, and green. Simultaneously, the endocarp, which will eventually become the hard pit, begins to harden around the developing seed. This hardening protects the nascent seed as the fruit continues its initial expansion.
Cherry Ripening Process
As the cherry matures, it undergoes complex physiological changes that define the ripening process. Initially, the green fruits begin to transition, often showing a “straw-colored” hue or a slight blush, depending on the variety. This early color change signals anthocyanin accumulation, the pigments responsible for the characteristic red to dark red color of ripe cherries.
Concurrent with color development, significant changes occur in the fruit’s internal composition. Sugars, primarily glucose and fructose, rapidly accumulate, contributing to the fruit’s sweetness, while organic acids, such as malic acid, decrease, enhancing the overall flavor balance. The fruit’s texture also softens as cell walls break down, leading to a juicier, more palatable consistency. This stage represents the cherry’s full development, where it reaches its peak flavor and nutritional content.
Factors Affecting Development
Cherry development from bud to ripe fruit is sensitive to environmental conditions. Temperature plays a significant role; insufficient winter chill hours can lead to delayed or uneven bud break and flowering. Late spring frosts can severely damage developing buds and flowers, reducing potential yields. Optimal warm temperatures are necessary for fruit growth and ripening, as prolonged cool periods can slow these processes.
Sunlight exposure is another important factor, influencing photosynthesis and the production of sugars and other compounds essential for fruit development and quality. Adequate water availability, particularly during fruit expansion, is important for achieving optimal fruit size and preventing physiological disorders. Soil quality, including nutrient availability and proper drainage, provides the necessary foundation for healthy tree growth and fruit production. Successful pollination, often reliant on bee activity, is indispensable for fruit set, and the presence of pests or diseases can compromise tree health and fruit development.
Harvesting Cherries
Determining the optimal time to harvest cherries involves assessing several indicators of ripeness. Color is a primary visual cue; sweet cherries typically transition from light red to dark mahogany or black, while tart cherries achieve a bright red hue. The fruit should also feel firm but yield slightly to gentle pressure, indicating a juicy texture, and taste sweet with a balanced tartness.
Harvesting is best done in dry weather to minimize the risk of fruit rot, ideally in the morning after dew has dried, when the fruit is cool and firm. Cherries are typically picked with their stems attached, as removing the stem can create an open wound that makes the fruit more susceptible to spoilage. Gentle handling is important throughout the harvesting process to prevent bruising or crushing, which can compromise fruit quality and shelf life.