Secondary growth in plants refers to the increase in thickness or girth of stems and roots, resulting from cell division in the lateral meristems, specifically the vascular cambium and cork cambium. This growth causes the stems and roots to thicken rather than elongate, which is the result of primary growth occurring at the tips of stems and roots

. Key features of secondary growth include:

• It occurs mainly in woody plants such as dicots and gymnosperms, producing wood and thickened stems or trunks

• The vascular cambium produces secondary xylem (wood) inwardly and secondary phloem outwardly, contributing to the plant's increased diameter

• The cork cambium generates cork cells that replace the ruptured epidermis, forming a protective outer layer that reduces water loss

• Secondary growth supports the plant structurally, allowing tall woody plants to maintain stability and transport nutrients effectively

In summary, secondary growth is the lateral expansion of plant stems and roots through the activity of lateral meristems, resulting in thicker, stronger structures essential for the support and longevity of woody plants