The sweet, red strawberry is one of the most popular fruits, yet the tiny specks covering its surface are a source of common curiosity. Many people assume these minute grains are the strawberry’s seeds, but the botanical reality is more complex. These small, distinct structures are actually the true fruits of the plant, each one containing a single seed inside. The large, juicy red part we enjoy eating is not a fruit in the botanical sense, but rather the swollen, edible part of the flower known as the receptacle, making the strawberry an aggregate accessory fruit.
Achene Versus Seed
The small, hard specks embedded on the strawberry’s exterior are known as achenes, which are dry, single-seeded fruits that do not split open when mature. Each achene develops from one of the many tiny ovaries in the strawberry flower, encasing a single, true seed. When a strawberry is fully ripe, the visible achenes typically appear as pale yellow, light tan, or greenish-yellow dots against the red flesh. This coloration is a characteristic of the mature, dried fruit wall surrounding the seed.
The Role of Achene Color in Ripeness
The color of the achene is directly linked to the maturity of the fruit, acting as a biological indicator. Early in the strawberry’s development, when the receptacle is small and green, the achenes are firm and green or white. As the receptacle enlarges and ripens, changing to its final red hue due to pigments like anthocyanins, the achenes transition in color. This shift from green to pale yellow or tan signals that the seed inside is fully developed and ready for dispersal.
How Strawberry Seeds Grow
For the true seed inside the achene to germinate, it must first overcome a natural dormancy that prevents premature sprouting. In nature, this dormancy is typically broken by cold stratification, which mimics the winter conditions the seed experiences on the ground. Gardeners must replicate this by placing seeds in a moist medium and chilling them for several weeks. This cold, moist treatment prepares the embryo for growth, allowing the seed to sprout when exposed to warmer temperatures and light.
Propagation Challenges
Strawberry seeds require light to germinate, so they are typically sown on the surface of a sterile potting mix and should not be covered with soil. The resulting plants from these seeds are often not “true to type,” meaning they may not produce fruit exactly like the parent strawberry. This genetic variability is why commercial growers often propagate strawberries using runners, which are vegetative clones that ensure consistent fruit quality.