How Does a Grape Grow?

The Breaking of the Bud

The first part of the the grape's growth is what is called bud break. The vine develops tiny buds, which gradually begin to swell. This swollen bud has three shoots which have recently grown using energy stored in carbohydrates. As this shoots break through the bud, they grow tiny leaves which are able to begin to harvest energy from the sun using photosynthesis. When the weather is warm enough, these shoots will grow very rapidly, at a speed approaching 1 cm per day. During this time, these shoots are very vulnerable and are easily damaged by frost.

Flowering

Approximately 40 to 80 days after bud break, depending on the weather that the vine experiences. Initially these flowers start as little clusters. After a few weeks, individual flowers are visible. During this time pollination and fertilization of the flowers occurs. Many types of grapes are hermaphroditic, which means that they have both "male" and "female" sex parts. As a result, they are able to pollinate and fertilize themselves. Wind and insects can also help with pollination. Some species are also able to pollinate other species of grape vines.

Creation of the fruit

The fruit begins to form almost immediately after the pollination and fertilization of the flower. The flower produces a seed and a fruit (the grape) around the seed to protect it. Not all flowers get fertilized, and the ones that don't drop off the vine. These early grapes are hard and green and have very little sugar. They are also half the size of ripened grapes. As the grapes develop and ripen, they swell and obtain more sugar as well as change color. This color change is due to the replacement of chlorophyll, which is green, with other pigments.