The annual and biennial plants can be made to flower in one growing season by providing young plants or moistened seeds with low-temperature treatment. Vernalization is a process of shortening of vegetative phase and helping the plant to attain reproductive maturity faster for flowering. If the requisite period of low-temperature treatment is followed by a period of high temperature, the expected acceleration of flowering did not occur. This process is known as de-vernalization. The degree of de-vernalization lowers if the duration of the cold treatment was longer. The de-vernalized plant can be vernalized again by low-temperature treatment.