#23: Critters, Preditors & Pests (Part One)

February 1, 2023

CORRECTION:     Richard Grant, faithful KP reader, alerted me that I mistakenly wrote “Ethyl Acetate” in my last article instead of “Acetic Acid”.  (I ONLY did that to see if anyone was paying attention.)  Thanks, Richard, for the correction and please blame it on post-harvest / pre-Christmas fatigue.  Here’s something that I’ve wanted to write about….

CRITTERS, PREDATORS & PESTS (Part One)

Since humans started growing crops, farmers all over the world have had to deal with lots of big and small critters that damage plants and lessen crop volume and quality.  And not much has changed over the millennia.  Zillions of dollars are spent every growing season on fencing, soaps, ointments, oils, camouflage, noise devices, traps and repellents to thwart those pesky pests.  (If you are a home gardener, you’ll know what I’m talking about.)  There are lots of critters that can damage crops but for my next couple of articles I’ll write about the ones that we grape farmers have to deal with.

Problem Critter #1: Deer!                                                          

We all pretty much agree that those majestic bucks, gorgeous does and adorable baby fawns that propagate our county are beautiful wild animals.  They may be pretty to look at, but not when they are dining amongst the grapevines.  Deer may be herbivores (plant eaters) but the “House Special” would be fresh grapes.  Deer can simply decimate a vineyard in a very short amount of time, so we try to do everything we can to keep them away from the vines as those grapes ripen and become irresistible.  Aside from mountain lions (too few) and cars (too many) there isn’t much in the way of deer population control in our area.  We do have a deer hunting season here in Sonoma County, but many areas, even though they are considered “rural”, simply won’t allow hunting because of the danger to people.  The exception is that under California law an owner or tenant of property that is in danger of critter damage may apply to Fish & Game for a permit to kill an offending animal, but most farmers would rather find another means of keeping the deer away from their grapes.  (If I told my wife and daughter that I was going to shoot an offending deer that somehow got in our vineyard, they’d change the locks on the house!) 

What about using deterrents?

There certainly are no shortage of ideas.   You can purchase propane-powered cannons, ultrasonic deer repellent devices, scarecrows and motion activated water sprinklers.  You can raise large, fearless dogs and put them in the vineyard; you can try hanging human hair, using floral scents from deer resistant plants, spreading coffee grounds, soap, oregano, clove oil, garlic or even spraying with wolf urine. (I’ve been trying for years to find a cooperative wolf!)   All are touted, but, unfortunately, none are very effective.  The bottom line is that if you live in Sonoma County and have anything planted for either food or landscaping, deer are probably going to pay you a visit.

How about fencing?

There is only one surefire way to protect a vineyard from deer…and that’s fencing.  There have been arguments against fencing since humans began raising crops, sheep or cattle but I won’t get into that.  The bottom line is that a good fence will keep deer out of your vineyard.  Barbed wire (ouch!) is used to keep cattle and sheep inside an enclosed area, but remember that we are trying to keep critters out, not in.  There are basically two kinds of fences that grape farmers use to keep deer out of a vineyard:  an 8’ electric fence or an 8’ mesh wire fence.  Both have advantages and disadvantages and both are usually 8’ high (only SuperDeer can leap over 8’). 

Electric wire fencing:

Electric wire fences are made up of a number of insulated, horizontal wires that are connected to a charging unit.  When an inquisitive critter (who is grounded) touches the wire, it gets “zapped” with a jolt of electricity.  It is great deterrent and is almost invisible (good!) but has a maintenance issue (bad!).  Fallen tree branches from wind or high grasses after the rainy season (water conducts electricity) will short out the system and disrupt the electric charge, thus negating the fence’s effectiveness.  Deer always seem to know when there is a power outage (I think PG&E notifies them) and we’ve seen them literally dive headfirst through the wires!  Incidentally, the electric charge isn’t your normal 110v AC (alternating current) and it may be high voltage (4-5,000 volts), but it is DC (direct current) and it only “zaps” the offending critter for 1/10 of a second.  Trust me, if you back into or touch a wire, that 1/10 of a second “zap” will get your attention!  (Don’t’ ask.)  If the fencing is installed properly and maintained, there isn’t any real danger of the fence starting a wildfire and there is no danger of electrocution to you or to your pets as the “zap” may be shocking, but is only momentary. We discovered that our dogs might get “zapped” once, but it never seems to happen a second time.  (We always preferred high IQ dogs.) 

Wire mesh fencing:

The second way to fence is with an 8’ wire mesh fence that surrounds a vineyard.  The wire consists of connected horizontal and vertical wire welded “squares” and it has very little upkeep.  It also is easy to see, so the fence may not be aesthetically pleasing.  There are also 8’ fences made of plastic materials instead of hard wire, but we found out that raccoons love to chomp through the plastic at the fence bottom which will destroy the fence’s integrity. 

What kind of fencing do you use?

We’ve tried them all.  In the beginning we installed an 8’ mesh plastic fence only around our vineyard because we enjoyed watching the wild deer around the house.  But then raccoons ate through the plastic so we replaced that plastic fence with an 8’ wire fence, again only around the vineyard.  Then the deer started chomping on all the landscaping we had planted around our house (deer absolutely love to eat roses!).  The final straw came after our beautifully planted garden had been destroyed overnight, so we decided to encompass the entire 20+ acres of our land, including our home, our garden and both vineyards.  At that time, we decided to install an electric fence.  It is almost invisible and, unless there is a short or the power goes out, it’s been working very well.  Voila!  No deer in the vineyard!

Are all vineyards fenced from deer?

Nope.  Drive up and down Hwy 12 and you’ll see many large vineyards that aren’t fenced.  The car traffic tends to keep the deer away and many growers figure the loss of grapes in their large vineyard compared to the cost of fencing installation and upkeep would be a push. 

Next month, more CRITTERS!

Since this is my first article of the new year, Suzy and I would like to raise a glass to you and wish you a wondrous 2023!  Our usual GlenLyon Scottish toast may be “Slainte M’hath” (“to Your Health”) but here’s an Irish toast (my heritage) wishing you Abundance in the New Year: “May your glass be ever full.  May the roof over your head be always strong. And may you be in Heaven half an hour before the Devil knows you’re dead”.  We have much to be thankful for here in “God’s Chosen Spot on Earth” (Luther Burbank).  Tonight, while you’re sipping some wonderful Sonoma wine, raise that glass and toast to those passionate men and women who work very hard to put that wine in your glass!

Squire Fridell