After losing their leaves during the winter season, trees begin to grow new leaves and flowers once again in spring. According to Top Marks, this occurs because with the coming of spring, soil and air temperatures start to increase as the length of daylight gets longer. In order to grow and make sufficient food, plants need a good supply of light.
As the length of days get shorter in autumn and temperatures decrease, trees set themselves in a dormant state, only to burst into life in spring, says Phys.org. Northern Woodlands states that it is this dormancy that enables trees to avoid unfavorable environmental conditions. There are certain types of trees that produce catkins or blossom just before their leaves appear. On the other hand, there are some trees that grow new leaves first. This is because, in order to produce fruits and seeds, trees need to flower first. Northern Woodlands further states that in order for the warmth to force bud break, trees must first go through a prolonged exposure to low temperatures ranging between -5 degrees Celsius and 10 degrees Celsius. This triggers physiological responses in trees, which alters the balance of enzymes and hormones involved in inhibiting and promoting growth.