Research was conducted to determine the effects of different tillage methods on the soil bulk density and growth parameters of Watermelon (Citrullus lanatus). The study was carried out at the Vegetable Research Farm, The Oke -Ogun Polytechnic, Saki; with treatments at three levels of tillage (T0-zero tillage, T1-one pass of moldboard plow and T2-two passes of moldboard plow); all treatments replicated three times and arranged in three blocks in a Completely Randomized Block Design (CRBD). Each plot was (1.2 m x 1.2 m) with 1 m and 1.5 m gap between the plots and blocks. Tillage methods affected the soil bulk density and watermelon growth parameters as shown that one pass of moldboard plow (1.3 gm/cm3) had the greatest mean vine length, stem girth and number of leaves (5.3 cm, 3.1 cm and 13) respectively. Paired t-minitab 17.0 showed that the zero tillage (1.6gm/cm3) and one pass of moldboard plow (1.3 gm/cm3) bulk densities are significantly (p ≤ 0.05) different, while two passes of moldboard plow (1.5 gm/cm3) and one pass of moldboard plow (1.3 gm/cm3) are statistically (p ≤ 0.05) the same. The summary of analysis of variance of effects of tillage methods on the watermelon growth parameters, revealed that blocks had no significant (p ≤ 0.05) effects on all the growth parameters, while tillage had significant (p ≤ 0.05) effects on the mean vine length, stem girth and leaf area. Least significant (p ≤ 0.05) different therefore, revealed that one pass of moldboard plow (1.3 gm/cm3) significantly (p ≤ 0.05) increased the vine length and stem girth than other tillage methods. The study concluded that for a one pass of moldboard plow (1.3 gm/ cm3) at 11.5 % moisture content; the growth of watermelon could be enhanced on sandy clay soil, in the derived savannah of Southwest zone of Nigeria.