Nectarine trees, with their delicate blossoms, signal spring and promise delicious summer fruit. These flowers are not just ornamental; they are the first step in the tree’s fruit production cycle. Understanding this process helps in nurturing these trees.
Nectarine Flower Characteristics and Season
Nectarine flowers typically emerge in early spring, often before the leaves fully unfurl. These fragrant blooms usually appear in shades of pink, though some varieties may feature white overtones, and they possess five petals, presenting a visual similarity to cherry blossoms. The appearance of these blossoms is a direct result of the tree accumulating sufficient “chill hours” during its winter dormancy.
Chill hours refer to the cumulative time spent by the tree at temperatures below 45°F (7°C), a necessary period for breaking dormancy and enabling proper flowering and fruit development. Most nectarine varieties require between 600 and 900 chill hours, though some low-chill cultivars can thrive with as few as 200-300 hours.
The Role of Flowers in Fruit Production
Each nectarine flower contains both male and female reproductive organs, making them “perfect” flowers capable of self-pollination. These blossoms produce nectar and pollen, which naturally attract various insects, primarily bees. While most nectarine varieties are self-fertile and can produce fruit from their own pollen, the presence of pollinators like honeybees and bumblebees can enhance fruit set and yield. Wind, in contrast, is not an effective means of pollen transfer for these trees.
Following successful pollination and fertilization, the flower’s single ovary begins its transformation into a fruit. This process initiates with a period of rapid growth lasting approximately 30 days, during which most of the fruit’s cells form and the pit begins to harden. If flowers are not adequately fertilized, or due to competition for nutrients, many may naturally drop from the tree shortly after blooming.
Protecting Nectarine Flowers
Protecting nectarine flowers from adverse conditions is important for a successful harvest. Late spring frosts pose a significant threat, as temperatures dropping below 32°F (0°C) can damage or kill delicate blossoms, with damage occurring around 28-30°F (-2.2 to -1.1°C). Strategic planting in a sunny, sheltered location, possibly near a south-facing wall that radiates warmth, can offer some natural protection. Keeping the soil around the tree bare and weed-free can also help, as bare soil radiates more heat than mulched or vegetated areas.
For smaller trees, covering them with horticultural fleece, burlap, or even old sheets during frosty nights can trap warmer air around the blooms. It is important to ensure the cover extends to the ground and is removed during the day to allow for sunlight and pollinator access. Alternatively, overhead irrigation, where water is continuously misted onto the tree when temperatures are at or below freezing, can protect blossoms by releasing latent heat as the water turns to ice, insulating the flowers.
During the blooming period, it is important to avoid applying insecticides, as these chemicals can harm beneficial pollinators like bees. Many pesticide labels provide specific warnings regarding their toxicity to bees during flowering periods. Protecting these insects ensures their continued role in facilitating fruit production.