What does the recent cold in the Midwest mean for grapes?

It means if they are Vitis vinifera, they are probably all dead now. The classic European winegrapes have little resistance to extreme cold (or to various fungal diseases). But their sturdier American and Asian grape-friends have excellent cold resistance--often down to -40F!, whereas vinifera will die off at about 0 degrees F (and the Amer and Asian grapes have excellent disease ressistance, too). This is why I'm supporting grapes that are crosses between the classic winegrapes (vinifera) and the American and Asian grapes. These modern grapes also ripen earlier. The modern grapes are a win-win-win in every sense.

If you want to talk about foolishness, real foolishness is the expensive and time-consuming planting of Vitis vinifera in the Midwest, when those grapes just cannot live there. Those growers should be planting modern grapes instead. Modern grapes make great wine. When will they learn? It's a little hard to feel too sorry for them.


photo credit: alamy

So if we're in a phase of global warming, why do we see record cold temperatures this week?

Interesting: There is a logical answer: The warming of the polar caps means there's less temperature difference between the poles and the equator, and that slows down the jet stream, which allows more events that block the jet stream for longer periods. This effect contributed to the strength of Hurricane Sandy, and it also allowed the deep southward plunge of polar air this week, which is breaking century-old records.

Read the article here.

I guess the "good" news is that someday the poles will be much warmer, even than today, so when the arctic air plunges southward, it won't be so cold. (Of course I'm kidding--that is far from good news. Miami and NYC will be underwater long before that happens. What we all need to be doing now is to minimize fossil fuel burning. If we put solar panels on every sun-exposed roof on Earth, we could cut our fossil fuel burning by probably 75%.)

2013's triple whammy of record weather for grapes in the Pacific Northwest

What a year this 2013 has been, for grapegrowers!

1. Some sites in the PacNW saw record heat in July. Above 90 or 95F, a grapevine suspends the fruit ripening process, so very hot days are "lost time" and they can impair the production of fully ripe fruit.

2. The entire region had record rainfall in September, which had heavy impact on a small portion of regional vineyards. Ripening earlier, many of the modern varieties were harvested before the rains, but most of the vinifera had to keep hanging. Fortunately, most of those were able to "hang through" into a dry late September and October. But too much water can dilute the desired flavors in the grapes.

3. In December, we saw very frightfully cold (and suddenly cold) weather: Hermiston OR got down to -8F, Ephrata WA and Yakima WA saw -2F (breaking a record held since 1972), and even sheltered Hillsboro OR (just west of Portland) saw a low of 9F with two weeks of all-day sub-freezing temps. These sudden, extremely cold temps can kill vinifera grapevines, especially younger ones.  Modern varieties of grapes (hybrids) are fine at these temps, however--a real advantage of growing them, as they have hardier American grapes in their lineage.

Fingers crossed for milder weather in 2014!

(image credit: Kendall Jackson winery)

Winterizing pots of outdoor plants

I lost some potted grapevines one year, to winter's cold. They just died.

"But wait!" you might say. "Your varieties are cold-resistant." It's true--the modern varieties I'm growing have much better cold tolerance than vinifera do (due to the American grape genes in the modern varieties).

But, I say, that is only true for vines in the ground. The trunk and canes ARE cold resistant, but when the grape is in a pot its roots are exposed to the bitter cold, whereas the grape in the ground has roots which are protected from the cold by the insulating earth! The tops are cold resistant, because in the real world (before came along humans with pots) that's the only part of the vine that needed to be. That is why your modern grape varieties, which are very cold-tolerant, can die over winter in their pots. Of course vinifera would do the same.

So, here's what I did, headed into winter in the Northland: I put the pots (not only my grapes but my bonsai too) in a spot where they'll get rain but be sheltered by two walls of my house, which should add a little warmth. Then I piled bark mulch all around the pots, as if mimicking a raised soil level, as if the vines were in the ground. Here's a pic:

We'll see how it works. These vines are headed to my new rural vineyard, next year. They will grow on a gorgeous South-facing slope with great sun exposure, overlooking the pretty Lewis River.