Some growth parameters of pea (cv. Pleven 4) and vetch (cv. Obrazets 666) after treatment with organic fertilizer were studied in a field trial carried out at the Institute of Forage Crops, Pleven, Bulgaria. Humustim as organic fertilizer was applied through presowing treatment of seeds, treatment during vegetation and combination between both, at different doses. Ratios of aboveground weight to root system weight, aboveground height to root system length, as well as specific root length were determined. It was found that the growth variables of plants were positively influenced by organic fertilizer. The aboveground weight to root system weight ratios of pea ranged from 4.80 to 6.29 and was higher than vetch. Aboveground height to root system length ratio in pea ranged from 6.95 to 7.93, and in vetch from 5.30 to 7.39. The use of organic fertilizer at the dose of 1.2 L/t and treatment during vegetation resulted in better performance of root system and specific root length was 78.6 for pea and 84.3 for vetch.