Wachstumsruhe

Wachstumsruhe, in botany and horticulture, denotes a temporary phase during which growth and certain metabolic activities in plants are markedly reduced or suspended, even though conditions may still allow survival or later growth. It is a distinct, but related, concept to dormancy: Wachstumsruhe is typically a shorter and more reversible slowdown within an active growth cycle, whereas dormancy involves a deeper, often hormonally regulated cessation of growth that requires specific cues to be released.

The occurrence is common in perennial plants in temperate zones, including trees, shrubs, and perennial herbs. It can follow a period of rapid growth in spring and early summer and is often linked to seasonal cues such as shortening day length, cooler temperatures, or water limitations. The duration varies from days to weeks or months depending on species and environment.

Physiological characteristics include reduced cell division in meristems, limited elongation of shoots, lowered respiration, and accumulation of stored carbohydrates. Hormonal changes—such as relatively higher abscisic acid and lower gibberellins or cytokinins—are associated with the state, and environmental signals coordinate its onset and release.

Function and practical relevance: Wachstumsruhe allows plants to conserve resources and synchronize growth with favorable conditions. It may prime tissues for subsequent phases such as bud break or flowering when conditions improve. In horticulture and forestry, recognizing Wachstumsruhe helps in planning pruning, fertilization, and irrigation, and distinguishes it from true dormancy, which requires chilling or other cues to be overcome.