UPDATE: We no longer use these frost guard machine. But feel free to read about our experiment.
This is just the kind of photo that Cliff doesn’t want me to show you, but… it looks just the way we want it to look this time of year in our vineyards in early spring. We still have the possibility of freezing weather in the month of March and even into the month of April.
Notice, no green leaves, you have to look really hard to find any buds just starting to make their way in the world. This is a Viognier vine. This variety is well loved in Texas, but it is our earliest blooming white grape making it susceptible to damage from freezes late in the spring. Our first defense against freezing weather in spring is delayed pruning. With our long warm summers on the High Plains, we have time for the sugars to fully develop in our grapes without rushing their growth in the spring.
We delay the pruning of our Viognier till the very last, since the pruning tells the vines to wake up and start producing buds.
If you look really really close.
You’ll see some buds.
Our orchard is realizing that it is spring, but we would like the vineyards to stay asleep just a little longer.
As the vines start to bud out, there are times during April that we may want to heat up the vineyards to prevent freeze damage to the vines, so we are trying something new. Some of our friend’s have purchased huge, tall wind machines to recirculate warm air in their vineyards. They seem to work very well, but for various reasons, we are trying something different.
That’s why we have moved this butane tank out into the vineyards. Hmmm, let’s follow that yellow hose.
And there it is, but what is it…
It is an Agrofrost frostguard machine. Our friend, Steve, has started selling these machines. I am just learning about these machines myself, so I’ll copy what their web site says.
The FrostGuard has a gas burner and a powerful fan, driven by engine that runs on propane gas. You just have to start the engine, adjust the temperature and the FrostGuard does the rest. There is enough gas to last up to two complete nights. The success and effectiveness of the FrostGuard are a result of the temperature fluctuations that are created by the machine, and of the lowering of the humidity, reducing the possibility of ice crystals form. The big advantage to creating fluctuations is to use much less energy than raising the temperature above the critical values constantly, and still maintain effective frost protection for your crop. As a result, the input of energy is up to 10 times less than with other systems, and your crop is still fully protected. The FrostGuard and FrostBuster work in a similar way. The big difference between both machines is that the FrostBuster is powered by the tractor, which must be driven through the orchard at night, while the FrostGuard, once started, stays at the same place and needs no supervision. The outlet of the fan turns around 360° continuously, protecting an oval or circular area. Machines can be spaced out in groups in relation to the shape and area to be protected. Another important advantage of the FrostGuard is that it’s easy to spread the investment over several years: you can start with 1 or 2 machines and buy more during the following years. Therefore, no big initial investment is necessary. There are 3 factors that make the FrostGuard work:
- The increase of temperature.
- A very important factor is the creation of temperature fluctuations: at each rotation of the FrostGuard, the temperature rises shortly and drops again. These fluctuations create a big part of the protection that we get with the FrostGuard.
- Probably the most important factor is the influence on the relative humidity. Wherever the FrostGuard is used, the relative humidity goes down. Because of this, the dew point is raised significantly. Therefore, there will be less hoar-frost and less ice on the plants. Result: no or very little damage.
Warriors, ready for battle. What do you think?
Here’s a little better look.
And, no, I am not stupid. I will not try to use one of those in my house. Thank you. But, wait, I would like to have one of those in my orchard. Some how I don’t think that they are going to spare me one.
We bought about twenty-eight of these, and there are about fifteen more on one of the vineyards that we manage. It still seems to be in the experimental stage for us, but we are going to see how it works. Ours are set up to automatically turn on when the temperature goes down to freezing. The night before last when it went down to 33′ or below, some of them actually did turn on. It wasn’t that cold for long, but it was a great practice run.
Here’s another one. In this vineyard there are two on each row that they are placed on, at either end of the vineyard. The guys sat around with drawings to make sure that these would be positioned to cover the most area and for the most area to be covered.
See once again on the Tempranillo vine, no green leaves. But, yea, that’s what we want them to look like.
This photos may look gloomy now, but with a combination of delayed pruning, and these frost guard machines, we hope to have a healthy crop of Texas wine grapes even if we have some late spring freezes. These vines are actually the exciting promise of spring coming, and then summer growth, and then fall harvest. Thank you, Father, for the seasons of encouragement that you send.
Soon we can look at photos of beautiful green leaves and then beautiful grapes in the vineyards, but for now we are quite content to see just brown sticks that are getting ready for spring.
Blessings,
Betty
