This study evaluated the effect of phosphorus and potassium (PK) fertilizer levels and foliar seaweed extract on early and total yield productivity and the growth of globe artichoke plants. Field experiments were conducted over two seasons on loamy–clay soil at the vegetable research farm, of the Faculty of Agriculture, Alexandria University, Egypt. Fertilizer levels of 0, 25, 50 and 75 mL L−1, and seaweed extract concentrations of 0, 5 and 10 mg L−1, individually and in combination, were used. Globe artichoke plants treated with PK liquid fertilizer, with and without seaweed extract, showed critical increases in growth (plant height and number of leaves per plant as well as foliage dry weight), yield, and some chemical constituents compared to untreated plants. The PK3 fertilizer level and 10 mL L−1 seaweed extract as a foliar spray showed greater effects than other combinations.