dormant seeds , e . g ., of lettuce , tomatoes , peppers , carrots , onions , impatiens and primrose , are produced by soaking non - dormant seeds in a solution of gibberellin synthesis inhibitor , preferably tetcyclacis , preferably in the dark at 25 ° c . to 350 ° c . for at least 24 hours , washing to remove the inhibitor and drying to original seed weight . the dormancy can be released by application of a gibberellin , and in some cases by moist chilling , or exposure to light at 25 ° c . to 35 ° c .