Successful cultivation of the sunflower in the UK depends heavily on the sowing of suitable varieties at ân âppropriate time. Data from 66 open pollinated half-sib families of sunflower were analysed to determine the impact of the normal and late sowing dates on the expression of six metrical traits namely, height at 6 weeks after sowing, flowering time, height at the time of flowering, head diameter, seed set and area of seed set. Comparisons of the rneans revealed that the Iate sowing grew significantly faster and taller and took 7 days less to mature. The normal sowing, on the other hand, set significantly more seed. The two sowing dates did not differ critically for the remaining traits. The performance of the families was observed to be consistent across the sowing dates and there was little coincidence of family x sowing date interaction or family x micro environmental interaction for any of the traits. These observations were further supported by the significant and positive correlations between the sowings while the associations between traits did not different uch either. Only one out of the 15 inter-trâit correlâtions was found to differ significantly. The important implications of these results are discussed and it is shown that early sown crop will be commercially more successful in the UK.