The effects and after-effects of different low-temperature treatments on growth, biological productivity and resistance of bedding ornamental plants were studied during vegetation period outdoors. Low-temperature treatments of different schemes increased resistance of Tagetes pland Calendula plants compared to untreated plants, stimulated biomass accumulation and growth of vegetative organs in Tagetes, and shoot growth in Calendula plants. After-effects of lowtemperature treatments were pronounced as increase in growth and biomass accumulation in Tagetes and inhibition of biomass accumulation in Calendula plants. Pre-treated by low temperature bedded Tagetes plants responded to daily temperature alterations by increased resistance, which maximum was equal by the end of the vegetation period in all experimental plots. Pre-treated by low temperature bedded Calendula plants have been characterized by one-time unstable increase in plant resistance in response to temperature fluctuations.