We sometimes forget not everyone lives among the beautiful vines of Northern Sonoma, so here is a basic description of the vine cycle in a typical year. Enjoy.
During the winter months the vine is dormant. All the leaves have fallen off, the green shoots from the previous season get lignified (become woody) and the plant basically hybernates. Nothing goes on in the vineyard, we normally take a trip to Hawaii or Florida... somewhere with warm waters.
When Spring approaches and daily temperatures rise, sap starts traveling from the roots to the canes, the dormant buds awaken, swell and eventually burst with the beginning of a new shoot.
One by one, leaves unfurl as the vine soaks in sunshine and converts it to growth energy. Green shoots grow inches per day and we try to leave them alone at this stage. even a strong wind can damage and detach whole shoots... Every shoot will normally develop two primary clusters of grapes (some years and varieties will have more, but that is another story...). From March until mid-May (or so) the shoots lengthen and the stalk of unopened grape flowers gets ready for action.
The delicate clusters are ready for pollination. The flower caps fall off and the vine flowers do that thing the birds and the bees do. If the weather is mild and even, we have a good "set" meaning many of the flowers become berries. The Grapevine (Vitis Vinifera) is a self-pollinating plant.
Once a flower is pollinated, a berry is starting to form, "BB" sized in beginning but soon to swell up and fill up with grape yumminess....
The berries grow and fill the cluster (we call it "cluster closure") the vine still makes more leaves, a phenomenal array of "solar panels" converting sunlight, water and carbon dioxide into sugars.
The French term that denotes the color change. Red grapes turn pink and then red, white grapes turn from green to tansluscent green/gold (depending on variety)
Now the vine is ready for action... as the seeds mature and they become ready to fulfill their function (get eaten by an animal and dropped with some choice organic matter somewhere, only to sprout and create another vine), acid levels drop, sugar levels go up, the skin of the berry softens. Then come the EVIL HUMANS and distrupt the process... just so they can make wine!
CRUNCH TIME! we like to pick our grapes at night, when temperatures are cool. Good for the grapes, good for the wine AND good for the hard-working field hands who don't have to work in the 90-degree heat.