Chenopodium album L. plants, grown under controlled environmental conditions on different levels of soil nitrate, produced seeds with proportionately different NO−3 contents. Regardless of the endogenous NO−3 content, few seeds germinated in water or upon treatment with KNO3. Ethylene promoted germination, and the extent of germination was positively correlated with the endogenous seed NO−3 content. Combined application of ethylene and KNO3 in the dark had a synergistic effect on NO−3 ‐deficient seed. The synergism between ethylene and KNO3 was attributable to the NO−3 moiety of the nitrate salt. Ethylene and light showed moderate synergism in seeds with low or high endogenous nitrate. Addition of nitrate, however, masked the interaction between ethylene and light. Gibberellic acid4+7 (GA4+7) or red light, each alone or combined with KNO3, had little effect on germination. When applied together in the dark, ethylene and GA4+7 synergistically enhanced the germination of NO−3‐deficient seed. The combined effects of the two hormones on this seed were further enhanced by the addition of KNO3. There was no synergism between ethylene and GA4+7 in NO−3‐rich seed. These interactions among GA4+7, ethylene and KNO3 were not affected by light. The results confirm and further elaborate our earlier finding that the sensitivity of C. album seeds to ethylene may depend on nitrate availability.