Crop architecture in winter wheat is shaped by cultivar, sowing density (s.d.) and seasonal growing conditions. This study assessed the effects of cultivar and s.d. on selected agromorphological traits and productive tillering in four winter wheat cultivars — Glosa, FDL Abund, Python and Promitor — grown under the pedoclimatic conditions of Moara Domnească, Ilfov County, Romania, during the 2022–2023 and 2023–2024 agricultural years. The experiment was arranged as a bifactorial 4 × 5 split-plot design, with four replications. The tested s.d. were 350, 450, 550, 650 and 750 germinating seeds (g.s.) m⁻²; Glosa and 550 g.s. m⁻² were used as the cultivar and s.d. controls, respectively. Spring plant density, productive tillering coefficient (PTC), plant height, number of spikelets per spike and number of grains per spike were analysed separately for each year. The two seasons differed in precipitation regime, with 445.0 mm recorded in 2022–2023 and 623.2 mm in 2023–2024, compared with the multiannual average of 640.6 mm. Higher sowing densities were associated with increased spring plant density, with maximum values recorded at 750 g.s. m⁻² in both years. Conversely, the lowest s.d., 350 g.s. m⁻², was associated with higher PTC, greater plant height and more developed spike traits, suggesting a greater expression of individual plant productivity under lower interplant competition. Cultivar response differed according to trait: Glosa (control) and Python showed favourable productive tillering capacities, FDL Abund recorded higher plant height and grain number per spike and Promitor tended to form more spikelets per spike. Overall, the results suggest that cultivar and s.d. should be evaluated together when interpreting winter wheat crop architecture under the pedoclimatic conditions of southern Romania.