Studies to evaluate the wheat performance by silicon (Si) application under late sown conditions were carried out at Agronomic Research Area University of Agriculture, Faisalabad during 2010-11 and 2011-12. The study consisted of total four experiments. Prior to field experiments, two pot experiments were carried out in green house at Agronomic Research Area to optimize the best source and rate of Si both as soil and foliar application. Best Si source was determined from using sodium silicate, calcium silicate, and silicic acid, whereas Si level was optimized using four concentrations (0, 50, 100, and 150 mg/L) both as soil and foliar application. Both the experiments were carried out in green house using completely randomized design with three replications. Results revealed that Si from source Ca-silicate at the rate of 100 mg kg -1 as soil applied and 100 mgL-1 as foliar spray gave maximum improvement in crop growth. After the optimization of Si source and level from green house experiments, two field experiments were conducted at using the Randomized Complete Block Design with split-split arrangements. Three sowing dates (10th Nov, 10th Dec, 10th Jan) were placed in main plots, while wheat varieties (Sehar-2006 and Faisalabad -2008) and optimized dose of Si at different growth stages (control, basal, tillering, booting and heading) were placed in sub-plots and sub- sub plot, respectively. In first field experiment Si was applied as soil application but in second experiment it was applied as foliar spray at various growth stages. Data regarding the crop phenology, allometry, agronomic and biochemical traits were recorded using the standard procedures. The data so collected were analyzed statistically by using the Fischer’s analysis of variance technique and LSD at 5% probability was used to compare the difference among the treatments’ means. Results indicate that maximum days to maturity, growth attributes, yield and yield components and biochemical parameters were observed when Si at the rate of 100 mg kg -1 as soil or 100 mg L-1 as foliar was applied at the heading stage of wheat. Moreover, soil application of Si performed comparatively better than foliar spray.