Grape preparations

So a little history about this grape vine. Although it now looks like this:

December 30, 2015

The early days:

I purchased it from Home Depot three, maybe even four, years ago. It started out as a 2 year old (according to the package) woody stalk, no more than three feet tall including the small pot it came with. I moved it into a larger pot, at about 10 or 15 gallons, using potting soil from the UH greenhouse. It proceeded to grow and under varying degrees of care until I graduated in May 2015. 

The uprooting:

By then, the pot had been moved out of doors for about a season and roots had plummeted out of the pot and into the earth around it. I wanted to bring the grape home with me since we were moving into an apartment where we would have a patio (partially pictured in the photo above). So I dug out a circle around the pot, adding about 2ft to the diameter of the root system I would claim. I did have to cut some of the roots, even the one I suspected to be the main tap root. But, I think under the circumstances I did an ok job. I then immediately went to Home Depot and purchased potting soil and the pot pictured above. I would say that's about a 20-30 gallon pot, although it is plastic. I may transfer the plant/soil to a new ceramic pot in March. (I have many many such plans "for the Spring.")

The dilemma:

Should I cut it back? How much? I know grapes require pruning. But exactly how much? and when should I do it? Did I already miss the window by allowing so much woody growth?

And so today I set out to do an extensive internet search.

According to the internet:

• "...15 to 20 gallons of potting mix. ... pots that are at least 24 inches wide and 16 inches deep ..." (Site #1)
• "Grape vines appreciate having full-sun... By late winter, after the big frost but a bit before it starts growing again, it is time to the first big pruning. ... make a diagonal cut away of the bud, just a little over the [bud] ... The goal here is to trim your plant so only the two lower healthy buds remain." (Site #2)
• This website also continues on with a good explanation about a space-saving training technique, but I will leave that for another time.
• "In the first winter, ...keep the strongest stem. ... [Second winter]...a straight trunk and a set of side branches. ... leaving about 10-15 buds in each arm during the winter of the third year." (Site #3)
• "Umbrella Kniffen training method ... select the strongest cane...remove the rest. Cut the cane back so that there are only two or three buds left. New shoots will emerge from these buds. ... shoots reach 6 to 10 inches in length, select the best one and remove the others." (Site #4)
• Wall of text I couldn't bring myself to read: Site #5
• "remove the majority of wood produced the previous season – until about 90 percent is pruned off... from January through the first of March, when the grapes are dormant. ... Grapes are produced from buds that will grow into shoots on one-year old canes. [Canes are] thicker than a pencil in width and as close to the trunk as possible (when cane pruned)." (Site #6)
• There are two types of grape pruning—cane pruning and spur pruning. Mature plants should be pruned yearly to remove all growth except new one-year-old fruiting canes and renewal spurs.
• To cane prune, select two to four new fruiting canes per vine. ...leave about 15 buds per cane. ...leave about 30 buds per plant. ... Leave a one-or two-bud spur cane near the fruiting cane with one or two buds each. These "renewal spurs" will produce the fruiting canes for the following year and thus maintain fruiting close to the trunk. All other cane growth should be pruned off.
• To spur prune, prune along main canes to leave two- to three- bud spurs, each four to six inches apart. Leave no more than 20 to 80 buds per plant, depending on the type of grape. Remove all other one-year-old wood.
• "The key to pruning grapes is understanding their fruiting habit. Grapes produce the most fruit on shoots growing off of one-year-old canes. If you have too many old canes (from no pruning), then you’ll get fewer grapes. If you prune back your vines completely each year, then you get lots of new growth, but again, few grapes." (Site #7)

So, I think I still have much to learn. I wish I could find more photos.

But the take home lesson today is: Prune heavily between February and March, and give some serious thought to my grape-shape-plan before I make my final cuts... Also, move it into a sunnier place, haha.

Also, I should get a fan for air circulation.

Also, one more site before I go: http://www.gardenguides.com/86085-plant-grapes-texas.html