acorns

Acorns are the seeds of oak trees, produced by species in the genus Quercus. They are true nuts, consisting of a hard shell containing the kernel and typically attached to a rough cup-like cap called a cupule. Acorns vary in size and shape by species, but are generally brown and oval when mature.

Most white oak species produce acorns in a single growing season, while many red oaks require two seasons before the nuts are mature. Germination behavior also varies: many acorns fall in autumn and sprout in spring after a period of dormancy, whereas some require cold stratification to break dormancy before germination.

Acorns occur in temperate regions of the Northern Hemisphere, from North America to Europe and Asia. They are common in deciduous and mixed forests and are also planted in parks and urban settings where oaks are grown.

Ecologically, acorns are a crucial food resource for wildlife and play a role in mast-seed cycles. Squirrels, jays, mice, deer, and other animals cache acorns, aiding their dispersal and survival during scarce years. Acorns are high in fats and carbohydrates and contain tannins, which can be bitter and reduced through processing.

Humans have historically used acorns as a food source after removing tannins by soaking, leaching, or roasting. They can be ground into flour or used as a coffee substitute. Nutritionally, acorns provide energy-rich fats and carbohydrates with variable protein content and low, but species-dependent, tannin levels.

For propagation, collect recently fallen acorns, clean and inspect them, and plant in well-drained soil. Planting in autumn supports natural stratification, improving germination and establishing new oak seedlings.