More double-trunking: age of trunks.

I talked last week about double-trunking. I should make a few additional points on this topic while it's pruning season. You shouldn't wait for freeze, diesease or mechanical damage to replace a trunk. You should consider keeping trunks of various ages; one older trunk and one young trunk is the best combination in our climate region. A younger trunk means fewer years of freezing, splitting, cracking and scraping. Even on healthy vines you should build a replacement plan into the pruning schedule every few years, if not more frequently. I've included another photo of a GDC trained Norton vine. Last year I allowed several suckers to grow up on this vine even though both cordons are healthy and productive. One of these new suckers looks like it will be a viable trunk (highlighted in yellow), so that I'll be able to prune off one of the old cordons (pink) and wind up with trunks of two different ages. The replacement trunk will also be straighter and correct the problem of the split of trunks being too high on the vine, which we talked about last week.

One other tidbit of information this week. As the wind chill dropped down to minus twelve degrees this week (and yes, we did have days of 70+ weather and tornados not three weeks ago), I started to worry about vine death. A friend pointed out though that vines don't experience wind chill because they have no mosture as a result of going into dormancy. That's a relief, as wind chill is often ten or even twenty degrees lower than acutal temperature.

Multiple trunks

In a climate that features cold winters, one technique you can use to keep your vineyard in production is training multiple trunks. Instead of a single trunk and head, you train up two trunks. This applies to short trunks on VSP-trained vinifera as well as long trunks on trailing varietals like Norton trained on a high single wire or GDC trellis. Our vines take a beating by our cold winters and by tractor damage, and an entire trunk might be killed down to a low spot on the vine. Having two trunks means that a damaged trunk can be eliminated and a new trunk trained up in its place, while the second trunk helps keep the vineyard in production with minimal losses. Of course, if both trunks are obliterated by a deep freeze, your double-trunking is for naught, but that's the risk of continental climate viticulture.

Here are a couple items to consider when training up trunks: first, have the trunks start from as low down on the the vine as possible. Photo A shows a VSP, spur-pruned Traminette vine with two trunks coming right out of the ground. On a grafted vine, you'd want to be above the graft union, but still low as possible. Photo B shows the same varietal, but the two trunks split off half way up the vine. The problem here is that if the area below the split is damaged, you'll lose both branches of the trunk and have to start from lower on the vine.

Practicing what I heard Kevin Ker (of the Cool Climate Viticulture and Oenology Institute at Brock University in Ontario) recently refer to as "spare parts viticulture" is essential. It might even be wise to keep a young sucker cane every year as a possible third trunk. In Photo C you'll see a GDC trained Norton vine with two healthy trunks, numbered 1 and 2. I've left a cane from last year (#3) as an insurance policy. It might make a great replacement trunk due to its youth and the fact that it is ruler straight while the other two trunks are a little more twisty than one would like. Straighter trunks are easier to work under without catching equipment and damaging the vine. Plus trunk #3 it starts lower down on the vine. I may just keep this one to replace one of the other trunks even if all three survive and are healthy. I'll talk more about the age of your double-trunk system in a future post.

Articles, blogs, links

_ Georgia (USA) vineyards experienced some of the same difficulties that we did from the spring freeze event.

_ Here's a tip on marketing your wine: raise the price.

_ Here's another guy who's doing a similar project to mine. What's more, we're practically neighbors, and he is also a student of the Godfather.

Winter soybean oil spray

If you grow grapes in the Midwest, the last thing you want to think about in February is spraying your vines. When you make 10 to 15 applications per year, you relish the break that the cold weather brings. I like going down into the workshop and seeing the spray rig put away for the year.

But this season I'll be adding another spray to the schedule. In mid-February, I'll be applying a spray of 8% soybean oil. The reason for this spray is to delay budbreak in an attempt to avoid damage from spring frost events. I recently saw Imed Dami of Ohio State University give a convincing presentation on the affects of spring oil applications. Dami who puts out a useful grape-wine newsletter at OSU, studied both stylet oil and vegetable oil, and the latter had fewer problems with pytotoxicity and reduction in yield. But at a rate of 8% or less, vegetable (soybean) oil sprays delayed budbreak anywhere from 2 to 19 days under the right conditions. Also, vines deacclimated slower. Deacclimation is the process of getting ready for spring, and vines that start this process are more susceptible to freeze and frost events. Dami recommends using a spreader-sticker like Latron B-1956 at 1% along with your 8% oil. He says that you can spray 200 gallons or more per acre.

The best way to keep your buds from getting fried by frost events is to do whatever you can to delay budbreak. That means pruning as late in the season as possible, or even rough pruning, leaving longer spurs or canes; the buds on the end of a spur or cane will break first, delaying those closer to the trunk. If you leave long canes, it could delay some of the buds you intend to keep by a few days.

So late pruning, rough pruning and oil applications are three methods to keep those buds from breaking until after frost danger has passed. It's a lot more work, and it may help or it may not be necessary. In the worst case scenario, you can do all these things and still experience damage. But that's the nature of nature.

One note on the spray rig in the photo. That's what I use for my test vineyard, and it will probably get me through my first pair of seasons in my 1/2 acre planting. After that I'll want to switch to an airblast sprayer to make sure I get good coverage on the fruit, since vinifera is more sensitive to diseases. It's an ATV sprayer that runs on a 12 volt battery, plus a gas mask, rubber boots, chemical gloves. I pull it up and down the hill in a hand cart. Only the disposable plastic suit is missing. I really hate all this stuff, but you gotta do what you gotta do. If I someday strike it rich I'll move somewhere where I don't need to spray.

January vineyard calendar

After two seventy degree days, all of the recent snow cover is gone. The ice that you can see on these Norton vines has melted. It's strange weather for early January, and I hope it doesn't begin to deacclimate the vines before a new cold snap. Would be much better for the vines if it were to get cold and stay cold. As I sit here now I see a brown bat circling outside, something I've never notice before this time of the winter, and also never this early in the day. Aren't they supposed to hibernate? I picked up a tick in the vineyard today as well. All this strange weather comes after my local power company mailed us an entire magazine denouncing climate change. They say it's just a frenzy stirred up for political purposes, and that it's a way for university scientists to score grants. Here's a quote: "Global Warming has become a $4 billion per year industry." Oh, and how many billions did Exxon bring home last year? Forty-something, I believe. That's the fossil fuel racket; they'll say anything to keep the dough rolling in. Sorry for getting off track. You can always trust your local coal pusher when it comes to sound climate science, right?

Well, I'll still pretend like it's a typical January and mid-winter rather than spring. Here's my vineyard calendar for this month.

1. Make a pre-planting checklist of everything that needs to happen before the new vines arrive from the nursery in March


2. Place order for all of required planting/trellis materials


3. Review reference materials: is there anything new that has been published? Are there new editions of materials such as the trusty spray guide?


4. Pre-prune heartier varietals. I wouldn't touch vinifera varietals until March if possible, though, to help delay budbreak. Right now I'm just doing a little clean-up on Nortons.


5. Check your applicator/chemical license to ensure it's up to date and place order for all early season sprays. I'll now include a March application of soybean oil to help delay budbreak. This is on top of the usual early lime-sulfur sprays


6. Review your business plan and see how you're making progress on long-term goals


7. Meet with your accountant to get paperwork ready for tax season


8. Cook and eat well, and drink lots of good wine

To augment my final item, I should mention that my recent favorite budget-friendly finds are a Clare Valley Austrailan Riesling and Primus, a Carmenere, Cab Sauv and Merlot blend from Chile. Both around ten bucks. The Riesling was un-German. Not that I have anything against the German version, but this was bone dry and raw, maybe even a bit of straw or grass. Many folks don't like those characteristics, but I thought it was interesting on top of the the typical melon and citrus of the cooler climate versions, and it also might hint at the kind of Riesling that might develop in our hot summer conditions here in Missouri. I already want to amend my vine order and plant some. It's a tendency you have to learn to fight, otherwise you'll wind up with twenty rows of different grapes and twenty different budbreaks, veraisons, harvests, etc, plus not enough of anything to make a barrel.