The effects of high dilutions of Cymbopogon winterianus (citronella) on the growth and germination of Sida rhombifolia are analyzed; 5 homeopathic dilutions (3cH, 6cH, 12cH, 24cH, 30cH) and a control (water) were used, with 5 repetitions. Variables analyzed were the primary growth of the root system, length of the shoot, fresh mass total, germination percentage and germination speed index. All dilutions stimulated the primary growth of the root. Dilutions 3cH, 6cH, 12cH and 30 cH stimulated the growth of the aerial parts and 24cH inhibited it. Dilutions 6cH, 12cH, 24cH and 30cH stimulated a larger production of fresh mass than 3cH. Dilution 12cH resulted in the largest germination percentage while 24cH in the lowest. Dilution 12cH resulted in the highest score in the germination speed index, while 3cH and 24cH in the lowest.