Whining about grapes

I inherited an overgrown garden with the purchase of my house. Thick and green, I worked at identifying what I had. Many of the plants have turned out to be sub-tropical, commonly used as houseplants in this climate. They were hooked up to irrigation that ran almost constantly. I deemed this to be a waste of money. If I am going to be watering that much it will be for food I can eat, or establishing native plants that will need less an less water over time. 
Bit by bit I trim, remove and sculpt it to my specifications.

I took out a lipstick vine last year. Lipstick vines, Aeschynanthus radicans, are fast-growing, twining vines that need little-to-no regular water once they are established. For this reason, they are great to plant along chain-link fences at the back or side of a yard. They attract hummingbirds with their bright red flowers. The vine in my yard was taking over the windows, claiming the roof and pulling down the electrical and other cables. It had to go. I planted sages & lavenders elsewhere in the yard for the hummingbirds and made sure the honeysuckle was trimmed back for optimum flowering as well.

To my surprise, before I could plant a new vine in the recently vacated trellis, a new one popped up. The California wild grape, Vitus californica, often grows through the underbrush, climbing whatever crosses its path. Most often exhibiting ruby-red fruit, the volunteer in my yard put out what I think of as green grapes. They were the best grapes I have ever tasted - a sweet burst followed by a tangy earthiness. One bunch was all that first crop turned out, an unexpected gift leaving me dreaming of more. Grapes can continue to grow and produce fruit for 30 years, so having vines in the garden is a great way to ensure homegrown fruit.

Unexpected crops taste so sweet!

Years ago, as an undergraduate working in a lab funded by the agricultural industry, I got a chance to care for different crops - mostly potatoes. I was loaned out to other labs in the building to help with apple, pear and other fruit tree harvest. In the winter, I’d huddle in the snow, carrying tools, wire, and twine in my freezing fingers as I followed the Greenhouse Lead who do the trimming and tying up of grape vines. I figured that qualified me to tend my own crop. I vaguely remembered that fruit only develops on older growth. I trimmed the barely yellow leaves back on a warm California December day, back to the woodish portions. One cut too many took out a quarter of the plant that I did not intend. So much for my past expertise.

A quick marker sketch.

I was pleasantly surprised by this year's growth, lush and thick, it threatens to take over the house like its predecessor. I decided to experiment with more horizontal growth, constantly trimming the upright shoots. I provided an additional freestanding trellis and tied the continued growth to bamboo stakes. However, there have been no sign of flowers and it is now June. The plant is pretty, so this is not a bad thing. It is time though to do some more research and find out what I can to improve fruit production in future years.

The National Gardening Association has a lovely website with useful tips (http://garden.org/ediblelandscaping/?page=201112-how-to). It cautions,

Pruning grapes can seem daunting and a mystery to the inexperienced gardener. However, with a little understanding and trial and error, you can learn to how to prune your vines to keeping them under control and producing well.

Continued reading told me that, as suspected, I trimmed my grape back too much. Fruit is produced on shoots growing off canes that are a year old. Complete winter pruning brings lots of growth, but little fruit. So how can I do better this winter for bunches of sweet berries next summer? Prune the vine back leaving 3 buds. This seems standard for any growing set up. Additional planning depends on whether one grows on a fence, stakes or an arbor. My method is currently a hybrid of stakes and an arbor. Winter pruning will therefore be two-fold: Make sure to leave 3 buds; and sculpt the rest to fit the yard and the available space. There appear to be one or two side shoots near the main trunk. Maybe they will be best on the stakes?

The Farmers Almanac (http://www.almanac.com/plant/grapes) has more good advice on training up the vines.

Put posts in the ground with wires. Ideally, these are placed one at 30” and one at 36.” Those are your two “fruiting wires” where you loosely wind your four “keeper” canes around. When you chose your four “keeper” canes, try to pick four closest to the trunk, and leave 4 to 6 two to three bud “renewals” near the trunk also. Place two “catch wires” at four feet, five feet and six feet so you have a place to tuck in the new growth. These will be your “fruiting canes” next year. At first, you will be looking to spread out about 30 buds total but in later years (especially for commercial applications) 45 buds is common.

The use of quotations to emphasize things makes the last paragraph more confusing than it needs to be. However, it provides a plan for pruning once winter comes. :)

2018 update: after two years of proper pruning and an added irrigation line, this year's crop was two large bunches of tasty grapes (though I ate one before remenbering to photograph the other). 😃