When Do Grapes Appear on the Vine?

Maturity

• Forming fruit is a grapevine's method of reproduction. Depending on the cultivar, grapevines can take between two and three years from the time of planting to begin producing fruit. Nurseries commonly sell vines that are between one and two years of age, making the vines about three or four years old when they begin setting fruit.

Annual Fruit Set

• Mature grapevines begin producing blossoms during late spring and early summer, usually in the months of May and June. Pollination occurs over the next week or two. After a successful pollination, the small clusters of tiny green berries begin to appear on the vines. This usually occurs within two to three weeks of blossoming, making the average fruit set around the middle to latter part of summer. The grapes begin changing color near the end of summer and continue to ripen until the time of harvest.

Factors

• The overall health and location of the grapevines are important factors in the reproduction process. Low areas in the landscape tend to act as a drain for cold air and tend to produce blossoms and grapes later than higher areas with warmer air. Grapevines generally begin growing when the soil temperatures rise above 50 degrees Fahrenheit, a condition that varies from climate to climate. Late season frosts can delay the onset of fruit production. Poor growing conditions, such as compact soil, drought and nutritional deficiencies, can also affect fruit production.

Harvest

• The time of harvest varies, depending on the intended use of the fruits and the specific cultivar. However, the general rule of vineyard harvesting dictates the average time of harvesting occurs about 100 days after the flowering cycle. Accurate harvesting determination relies on the amount of sugar in the grapes, as well as the acid levels. These conditions play a major role in the flavor of wines and jellies.