Grape vine flowers appears as soon as the newly formed clusters starts “opening”. What I mean by opening is explained in the following three images.
Grape Vine Flowers
Picture 1: The grape vine flowers are not visible yet because it is covered with flower caps, so in other words; what looks like berries in this picture, isn’t actually berries! This is still early days in the growing season, and as soon as the temperature rises, the grape vine flowers will become visible. However, at this stage, you will notice that the “berries” are compact, small and soft.
Picture 2: The grape vine flowers are still not visible in this picture, because it is the early stage of grape vine flowering. The grape vine flowers start to develop underneath the flower caps and soon the flower caps will turn yellow/brown and crack open. This in an important stage of berry development and mild temperatures, enough water, calm wind conditions and no rain, is the ideal climate for perfect grape vine flowers.
Picture 3: In this picture you can clearly see the grape vine flowers, with pollen carries and stigma. If you enlarge the pictures of the grape vine flowers, you will clearly see the flower caps that cracked open, revealing the grape vine flowers and pollen carries.
Grape Vine Flowers
Most wild grape vines you find in the woods are male or female plants and need cross pollination to produce grapes. Nowadays, 99% of the commercially grown grapes are self-pollinated and no cross-pollination is needed.
Another question I often receive about grape vine flowers, is about cross-pollination of different varieties. Some grape growers are concerned that if they plant two or more varieties in the same vineyard, that the grape vines will produce grapes that are not “variety-true”.
If you grow grape vines of different varieties in one vineyard, and all of them are self-pollinated, then you will not have any trouble with cross-pollination. The vines will only accept pollen from it’s own pollen carries.
Have a look at the picture and email from Eric below – I will reply below his email.
Danie,Can you tell me what’s wrong with my berries. This is the second year for my vines (they were probably 2 years old when I planted them. All the clusters are low on the vines and many of the berries in the clusters are dwindling away (see picture). Can you tell me what my problem is? I’m in a coastal region of Southern California.Thanks for your helpEric