Deer in the Garden

Beautiful though they are, hungry deer can ruin a garden. And deer are becoming more and more common in many places due to loss of predators, including deer hunters.

We have gardened here for over 20 years and in that time the deer pressure has gone from zero to overly destructive. Our part of California has been in severe drought for years, which seems to drive the deer to our irrigated plot of land. In previous years we have been able to coexist by using copious amounts of deer repellent and row covers over their favorite vegetables. But this year was way worse. We couldn’t get a garden established. They defoliated the grapes, raspberries and fruit trees. We had to do something if we were to continue to garden.

Oh, and the rabbit population exploded too. Since last summer we now have jackrabbits (the ones with the big ears) and cottontail rabbits in the yard and in the garden. Rabbits have an annoying habit of slicing plants off right at the base, leaving them to wilt in the sun. We haven’t seen it, but they seem to return the next night or two and remove the wilted plant. Perhaps they carry it off. To their dens to feed their zillions of children.

One of the turning points for me about deer has been learning how destructive they can be.  In this TedXFindhorn talk, Alan Watson talks about how red deer and sheep have almost completely deforested the Scottish highlands, eating everything down to a few centimeters in height. I’ve see something similar in my own garden. When deer repeatedly nip off the growing tips and young leaves of raspberries, they never quite recover. The plants are stunted and more susceptible to sunscald and disease. Of course the same is true for tomatoes, peppers, kale, cabbage, lettuce, fruit trees, roses or anything deer like to eat. Deer can literally destroy a garden farm.

[Image attribute: derivative work: Massimo Catarinella (talk)Red_deer_stag.jpg: Mehmet Karatay, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons]

Years ago we tried using a motion detector to turn on a light, a radio and a sprinkler. I came out one evening to find a small herd of deer browsing in our garden to loud country music and a shower. Later I heard that Irish Spring soap would deter them, so I loaded up the orchard with little bags of soap. They deterred my partner, but not the deer. The same was true for bags of blood meal. Shooting in their general direction with a pellet gun didn’t work. Chasing after them screaming didn’t work. Patrolling occasionally at night didn’t work

  • Deer are not deterred by lights, radios or sprinklers.
  • Deer are not deterred by Irish Spring soap or blood meal.
  • They are not deterred by random shooting, screaming or patrolling.

When it became clear we needed to fence the garden, there was some controversy about how best to go about it. We have a 1700 sq. ft. main garden surrounded by about 2/3 acre of orchard, berry plots, and open space, all on the side of a hill, surrounded by trees, hedges, driveways and neighbor’s haphazard fences. We knew the fencing would have to be done in stages. But it was not clear what stage would be best to start with.

I bought an outdoor camera for watching game trails at night. The camera has a motion detector and when it is triggered, it turns on a bank of infrared (IR) LEDs. Animals and humans can’t see the IR light, but the camera’s image sensor can detect it. The camera records video for a set amount of time after it is triggered. The first camera worked so well that I bought a second one to watch more deer with.

The cameras were key for determining how often the deer came and where they were coming in. We knew they had a main trail in by the neighbor’s house. The cameras showed us there was another main trail in at the top of the property.

We found out an important point:

  • Deer do not visit every night.

They visit every 3rd or 4th night. In prior years we were spraying deer repellent as a deterrent. This would usually happen the day after they came and ate some prized plant. We thought the deer repellent worked because we wouldn’t see any more damage for a few days. Then they would be back and we’d spray again. Deer repellent isn’t cheap and we went through a lot of it. It would have helped to know that the deer were coming on their usual schedule, regardless of how much repellent we sprayed.

An internet search informed us that we would need an 8′ tall fence to reliably keep the deer out (though 7.5′ might do it, or 6′ around a small garden). There is a lot to building a good fence. The corner posts should be heavy duty, properly braced, and often set in concrete. The line posts should be heavy duty and usually pressure treated wood, although metal t-posts may be used in between the heavier line posts.

We went to our local farm supply store to check out the 10′ tall t-posts needed for the 8′ fence. There was simply no way to install them; it would require a ladder on our hilly gopher-hole-ridden land, which was too dangerous. So we went with 8′ t-posts and picked up 330′ of 6′ welded wire fence at the same time. It should have dawned on us at the store that since it took two big young guys to put it in the trailer it would be too heavy for two soil analysts to deal with. But it didn’t and we ended up taking it back and getting 100′ of lighter weight welded wire, black PVC coated, 6′ fence from critterfence.com.

We decided to start by fencing off the main deer trail, thinking this would discourage them and they would go somewhere else. The 8′ t-posts are too tall to drive directly into the ground. So we had to dig a hole with post hole diggers, then put the post in, then drive it in with the manual post driver.  Since the post was only driven in a foot, we needed to cement it in as well. It was a lot of work, and a two person job, notwithstanding all the time spent on Youtube watching professional ranchers put in posts correctly. There was a steep hill involved, and the neighbor’s handyman. Eventually we got all of the posts in. Then we got the fence up.

Only to have it ripped down the first night. It turns out we had only secured it to the posts with plastic zip ties. It appeared that our neighborhood buck had encountered the new fence and tried it with his horns. The plastic ties were no match for his strength.

  • Always use stainless steel zip ties to secure fence to t-posts.

We straightened out the fence and got it attached properly.  That stopped the deer for exactly one night. Then they simply went around.

  • If there is a way in, deer will find it.

Then the rabbits got in the main garden and took out the cucumber crop. They nipped them off at the base and left them for the gardener to find in the morning, much to her dismay. That day we put up 150′ of 3′ tall chicken wire around the garden.  The chicken wire fence was attached to the hardware cloth gopher fence we had installed when we put the garden in. The hardware cloth was put into a 2′ deep trench, leaving 1′ exposed at the top. The gophers tunneled right under it. Although it didn’t work for gophers, it has worked really well to keep rabbits from digging under the chicken wire.

  • A hardware cloth fence 2′ deep in the ground won’t keep gophers out.
  • 3′ of chicken wire attached to 1′ of hardware cloth that is buried 2′ in the ground will keep rabbits out.

After this things started getting weird.

Deer were on a rampage, munching down raspberries and defoliating grape vines. One of us decided that in order to keep the deer out of the main garden she would extend the chicken wire fence upward, using monofilament line as a fencing material and white flagging as a deterrent (white is supposed to signal danger to deer).  The chicken wire fence was held up with 5′ pieces of 1/2″ galvanized electrical conduit, driven into the ground. Electrical conduit is relatively inexpensive and easy to work with. She added a PVC conduit sleeve and another 3.3′ piece of electrical conduit on top of what was there, making 6′ tall poles. The monofilament line was wrapped around and between the conduit, then flagging was attached.

This worked for a while, then the deer learned they could lift up the monofilament line and jump over the 3′ tall chicken wire. Deer were back in the main garden.

  • Deer are not deterred by monofilament line.
  • Deer are not deterred by white flagging.

The other one of us had researched 3-D deer fencing. With this system, two short fences are placed 2′ to 3′ apart. The theory is that since deer have eyes on the side of their heads they are not able to perceive depth very well and cannot determine how far apart the fences are. They do not want to be caught between two fences so they don’t jump them.

She was able to install 6′ t-posts for the primary fence mostly by herself, this time fencing the parts of the 2/3 acre that were not already fenced by the neighbors. She and the handyman put up 300′ of 4′ welded wire, black PVC coated fence.  For the second fence she used step-in electric fence posts – these are the kind that are used for temporary electric fence – and added three strands of white polywire electric fence. The step-in posts have the advantage of being easy to remove for mowing. It took a while, but when the 3-D fence was completed, the deer no longer came in.

So far the 3-D fence has had the most success. But now it’s the rainy season and the deer are not around much. After the 3-D fence was finished, we put a secondary electric fence around the main garden. That’s no longer on but the paranoia remains.

The wonderful thing is that after the deer were fenced out, the garden really took off. We’ve had bumper crops of late peppers, cabbages (of course) and even a good crop of late tomatoes. The basil was fantastic and we put up a lot of basil-infused olive oil. We were thinking we’d lost our gardening touch, but it was really just the predators.