Vineyard Seasons

The effects the weather has on a vineyard depends on the season. Weather fluctuations are watched very carefully as unseasonable weather can result in entire crops being lost.

Spring

Spring sees the vines awake from their dormant period over winter. As sunshine increases, the buds begin to burst. The biggest weather related danger at this time is frost. Frost can burn the leaves, or more severely the buds too. This can mean that the entire stem and that season's crop is lost.

Too much sunshine too early on in spring means that the vines will be vulnerable to frost for longer. Today, however, technology allows vineyards to protect themselves against frost. Chemicals have been developed, such as 'anti-stress' that can be sprayed onto vines to form a seal around the buds and protect them from frost.

Oil burners or heaters can also be used overnight in vineyards so that temperatures do not drop too much and the air keeps moving. This has allowed grapes to be grown in climates that were previously too cool.

Hail during the spring can cause damage by shredding the leaves on the vines and damaging the buds. The ideal spring weather is a late sunny period so that the buds are at less risk of frost damage.

Summer

At the beginning of summer, the vines begin to flower. Weather conditions at this time are extremely important - ideally the temperature should be 18-20 C for 10 consecutive days. During this period, heavy or prolonged rain can cause extensive damage to a vineyard, and can cause a whole crop to be lost.

Heavy rain prevents the flowers from pollinating and therefore the grapes from forming. If they do form they are often very small and the resultant crop is very poor. Hail at this time can ruin a whole crop as it can knock the fruit from the vines, as can strong winds.

Wind can also cause problems during pollination. The ideal summer weather is hot and dry with low humidity.

Autumn

For the grapes to ripen, warm sunny weather is desirable. The vines are kept trimmed to enable the grapes to receive as much sunshine as possible. A light breeze and low humidity are also preferable to keep the vines dry. When the humidity is high, vines are susceptible to mildew, which can ruin entire crops, although herbicide sprays can be used to help prevent this.

Long sunny summers also help, as the grapes are not left on the vines for as long. One of the reasons that English wines are more fruity and less sweet than wines produced on the continent is that the grapes have to be left on the vines for longer to ripen. The more sun the grapes receive, the sweeter they become and the higher alcohol content the wines will have.

Heavy rain before harvest can cause the grapes to rot on the vines before they are picked. Ideal autumn weather is warm and dry.

Winter

During winter, the vines are pruned right back. The weather is less important at this time of the year. While mildew can cause a problem, it can be controlled as there is no leaf coverage on the vines.

Vines are deep rooted, so even heavy rain at this time of year cause few problems, although heavy hail can bruise the vines near to spring.

Vineyards:
Vineyards - introduction
Vineyards - Denbies