As plants get older they go through a gradual developmental ageing process, from a juvenile phase characterised by rapid growth, good rooting potential, and orthotropic growth, to a mature phase characterised by slow growth, poor rooting potential and plagiotropic growth. This is of considerable importance from the viewpoint of propagation of 'elite' trees , since it is usually impossible to identify high quality plants at the seedling stage and difficulties in the vegetative propagation of adult woody plants arise due the physiological changes associated with maturation. The process of such maturation is very complex and poorly understood. The development of tissue culture techniques, has allowed for the mechanisms underlying maturation and rejuvenation of woody species to be better understood. The technique of cascade grafting of mature tissue to juvenile tissue has yielded ‘rejuvenated’ in several woody plant species. However the techniques of ‘rejuvenation’ rely on the availability of good quantitative markers for juvenile and mature plants. This study was concerned with two aspects of rejuvenation of mature oak material. The establishment of good quantitative and qualitative markers for in vitro growing juvenile and mature Quercus robur and Quercus petraea plants to enable the progress of rejuvenation to be assesed and the development of a system for in vitro cascade grafting of Quercus material. Shoot cultures of Quercus species of juvenile, adolescent and mature origin were examined for a range of morphological and physiological markers of juvenility and maturity in vitro. Morphological Criteria examined were angle of the shoot to the horizontal, stem length, stem diameter (tip, mid, base), leaf number, scale leaf number and shoot number. Image analysis was also carried out to determine leaf area, size, and breadth and length of leaves. Mature Q. robur clones showed a larger mid-stem diameter than juvenile clones, while mature Q. petraea clones were characterised by larger stem diameters at the apex, greater number of leaves on the shoot, shorter shoots and plagiotropic growth. Discriminant analysis on data for Q. robur and Q. petraea allows us to propose the following formulae for discrimination of juvenile and mature shoots where a negative value for Discriminant Score (D) indicates juvenility. Q. petraea Discriminant Score D = - 1.308 - 0.035l*Angle(°) + 2.41*Tip diameter(mm) + 1.435*Mid - Stem diameter(mm) Q. robur Discriminant Score D = - 3.546 + 2.418*Tip diameter(mm) + 2.202it=Mid-Stem Diameter(mm)