Grünachsen

Grünachsen is a term used in German botany and horticulture to describe the green, photosynthetically active axes of a plant—typically the young stems and shoots that remain green due to chlorophyll, as opposed to mature, lignified wood. The name derives from Grün (green) and Achse (axis). In practice, Grünachsen denote the parts of the plant that are still capable of photosynthesis while they are growing.

In plant development, Grünachsen originate from apical meristems and can also develop from axillary buds. Their growth is influenced by light, temperature, and resource availability. They are particularly characteristic of herbaceous annuals and the early stages of woody plants; in many species they may remain green for extended periods or reappear after pruning. As new shoots elongate, the axis often transitions from green to brown as it lignifies.

Functional role and agricultural relevance include providing a rapid source of photosynthates to support overall growth and canopy formation. For gardeners and fruit producers, distinguishing Grünachsen from older brown wood helps guide pruning and training practices to balance vegetative growth with fruit production or structural form. In some crops, excessive green growth can shade fruiting wood, so management aims to optimize the composition and vigor of Grünachsen.

See also: chlorophyll, plant anatomy, apical meristem, pruning, growth habit.