Keeping Critters Out of the Garden

You water and nurture a delicious tomato from seed and delight each day in seeing it grow and fruit. And then a critter eats the branches, roots or leaves. It’s a little tougher to love wildlife when they destroy your plants and food.

deer grazing near garden
Deer grazed near our vegetable garden while we filled our troughs with dirt. Notice the fence post on the right.

Some critters are easy to manage, but others not so much. Here, we have gophers, deer, gophers, elk, gophers, squirrels, gophers, rabbits, gophers, skunks and more gophers. I’ve listed a few tips for managing or controlling the ones that visit our gardens most often, which are deer — and you guessed it, gophers.

Directing Deer

The deer around our place have been especially active this year, and I believe one reason is that we did not mow our grass late in the season. A warm February produced new grass to graze as they ate up the old. Having them here more often is a double-edged sword. On the one hand, we get to enjoy them more often, but they have more opportunities to try out plants we’d prefer they didn’t eat.

xeric garden deer
Even after deer spent a winter munching regularly in our xeric garden, most plants did fine!

We have to fence many young trees and our vegetable garden to keep deer from destroying plants. Other tactics include trimming branches high enough to keep deer from reaching them while standing on their hind legs. We missed some low branches on our pear, and I noticed telltale signs the other day that deer had munched on the ends of several. Last summer, however, they ignored some unfenced tomatoes until well into fall.

We also have many deer-resistant plants in our ornamental garden, which avoids the expense and waste associated with choosing plants they love. Typically, only fawns graze plants such as rosemary, lavender, sage and butterfly bush. They’ve chewed a new kniphofia (red hot poker) to the ground and almost killed an oriental poppy. Bucks can also damage young trees by rubbing their antlers on the trunks, and small plants can be broken when deer step on them.

buck kitchen window
This buck spotted us through our kitchen window while he was grazing in our front yard.

We won’t exclude deer. After years, I still thrill at the sight of them, and love watching the herd grow as part of recovery following a past forest fire. So, here are a few strategies we use for protecting plants from deer:

  • Fence around vulnerable, favorite or valuable plants. And remember that a deer can go under a fence to munch just as easily as they it goes over one. Fencing can be attractive, as long as it’s also functional.
  • I have heard that fencing should be eight feet or higher, but we’ve done fine (so far) with 6-foot fencing (on 8-foot posts to allow at least a foot to 18 inches underground).
deer fence vegetable garden
The fence around our first vegetable garden area was inexpensive to build and has kept out deer.
  • Protect small individual plants with 5-gallon buckets (after sawing out the bottom). If it’s a plant favored by deer, we also strap chicken wire across the top of the bucket.
  • Although I don’t necessarily believe that repellants work, we have used Irish Spring soap in pantyhose to hang near plants with some success.
  • Don’t assume deer avoid prickly and thorny plants. They love rose bushes, though they tend to not eat much at once.
deer fencing
This fencing from old fence posts was a little high on the bottom, but only a fawn got to our sand cherries.

Gophers – the Bane of Our Existence

I do want to eradicate gophers, but we’re losing. The underground varmints can chew and claw their way through rocks, and probably titanium. We can’t even count the destruction they’ve caused, but we know they killed a dwarf apple tree, a lavender plant, and several other ornamentals. My favorite (or least favorite) example is the day we noticed that our new ornamental grass looked shorter. We blamed the deer for chewing on it, but when we got close, we noticed it had been shortened from the roots up. The stalks simply fell into the hole when we touched them.

gopher damage
Example of gopher damage near our peach tree. The tunnels collapse when deer, elk or people step on them, also making the ground a little unsteady for ankles.

The only control method that works for us is trapping. It’s a time-consuming business, but if we didn’t try to manage the numbers, the gophers would continue to multiply and take over the property. In fact, they nearly have. In one year, Tim trapped more than 80 gophers, and we still have lots of activity around the four acres. Our other method is exclusion, and the only way to exclude them is to fence underground. If you’re not sure whether you have pocket gophers, this publication from the University of California Davis has excellent photos of their mounds.

metal chicken scratch
Metal wire, or chicken scratch, from the home improvement store stucco section. We buried it about 22 to 24 inches deep and left some above ground to discourage bunnies and squirrels.

Between the deer and gophers, we’ve had to fence nearly two feet underground and six feet over. We dug a trench and purchased metal stucco wire to place into it, bending it slightly at the bottom. We also have some metal roofing material we’ll place along the side of our garden that borders our neighbor’s lawn. Here are a few more tips on gopher control:

  • An underground gopher barrier must be solid metal or metal wire with holes smaller than 3/4 inch. We used chicken scratch.
  • There are poisons for gophers, but we avoid them, because dogs and other animals might eat the pellets. Trapping seems cruel, but I think poisoning would be worse, frankly. The UC Davis site also discusses how to trap. Tim has often caught a gopher with only one trap per tunnel.
  • Gophers seem to prefer tender, young plant roots. I also am convinced that they gravitate to areas we’ve recently watered, but that’s just observation.
  • Use containers or raised beds. We use metal troughs and drill about half-inch holes, just large enough to support drainage. Surround raised beds with metal screen or solid metal, or dig down and cover the bottom of the bed with metal. Just remember that the  gopher barrier also can be a barrier to plant roots. Placing containers close to your home usually prevents deer damage.
  • Be aware of natural gopher predators. Many “safe” snakes, along with owls, cats and dogs prey on gophers. But you can’t count on it. A bull snake in our garden went after baby rabbits as well, and owls and cats don’t focus their hunting.
  • Cleaning up heavily weeded or covered areas can help control gophers. For example, we often discover mounds under low trees and bushes or in our irrigation ditch.

 

Integrated Pest Management: Preventing Bugs From Destroying Plants

Bugs on plants are more than a nuisance. They damage plants by sucking out sap, destroying leaves and transmitting diseases. I’m all for a balanced ecosystem, and I realize bugs gotta eat too, but there’s a point at which I have to choose between the bug and being able to eat the cucumbers I have spent time and precious water nurturing from seed. I might not be smarter, but I’m bigger and I have tools and creativity.

For many years in the past, home gardeners like us relied on chemicals to kill a bug at the first sign of trouble, and I’m so glad that the concept of integrated pest management, or IPM, has replaced that approach for so many people who care about the food they eat, the environment and preserving beneficial insects.

cucumber beetle
Cucumber beetles like any yellow flower, including the ones on this honeydew melon. This is the last known photo of this particular beetle…

Let’s break down a rather fancy term into the basics: start with the least harmful control. It’s really the same as prevention in medicine. Ward off a disease as your first choice instead of having to go through treatment. Here are the basic steps:

1. Start with healthy plants and good cultural management. This is the most important step to try to prevent insects in any yard or garden. First and foremost, plant native plants. I’ll never stop repeating this mantra. When you include plants adapted to your environment, they’re less likely to get stressed. There’s lots of research on the plant stress hypothesis because I guess some people disagree with it. But prevailing thought seems to be that plants stressed by drought or other conditions are more vulnerable to bug infestations and damage. It makes sense, and it’s still better to keep plants healthy anyway for flower or fruit production. Be sure to rotate crops, plant a variety of plants, and place plants in the right conditions based on shade or sun requirements, for example.

healthy tomato in container
This grape tomato plant is healthy and happy. It’s in a container with rich soil. I think it’s a little easier to control pests with containers.

2. Keep bugs away by weeding as much as possible and cleaning up debris to prevent hiding places. And cover seedlings with tunnels and row covers (with no holes) to keep bugs off while the plants are young and more vulnerable. Make sure plants are not too close together so they have airflow and can dry out as needed. Use mulch to cool roots and hold in water and compost to enrich soil. If one plant gets a disease, remove it from your garden and throw it out. Don’t lay it near the garden or compost it.

Covered seedlings
These lettuce seedlings have green beans for shade and cloth to keep bugs out until they get a little larger.

3. Hand pick bugs that appear if you can. This is not always easy, but if I can touch bugs, anyone can. Home gardeners who visit their garden regularly to water, deadhead flowers and check or harvest vegetables should inspect for bugs, especially in the morning. A major advantage of handpicking is that you can pick just the bad insects, causing no harm to beneficial bugs on your plants, who are there helping in your cause. See my Resources page for a few links to articles or photos that help identify beneficial insects. And here’s what I do when I pick off the little bug – throw it in a container of dish soap and water. I like to reuse a plastic container with a flip lid each year for easy, one-handed entry. Last year, it was an empty sanitary wipe jar. This year, I had used nearly all of my taco spice mix from Costco. I put the rest in a plastic zipped bag and had an instant bug bath. A blister bug infestation at our community garden one year had Tim and I doing a “swipe and boot stomp” method because those monsters bite and because of pure numbers. Our neighbor finally had to vacuum the potato plants.

dish soap and water for handpicking bugs in the garden
The little beetle featured in the photo above got a spicy ending courtesy of my handmade holding cell. All that’s inside is environmentally friendly dish soap (because that’s what I had), some water, and taco seasoning residue. The top snaps open.

4. When all else fails and you must use a pesticide, there are several organic choices. It’s also important to know that although an insecticide is organic, it still can be harmful, especially to bees and other beneficial insects. The three we keep on hand are insecticidal soap, Neem oil and Diatomaceous earth. Still, it’s recommended only to use these products once you have identified the pest or really have to do so. For example, I can spray a plant with water first to stop aphids before resorting to soap. I encourage reading labels carefully for time from use to harvest for any edibles, for specific pests they destroy and for any cautions about other insects, pets or warnings.

diatomaceous earth on ant hill in garden
This poor pepper has been attacked already by a gopher (and poor watering because it all floods down the hole the critter left behind). Now the stressed plant has an ant hill below. I am trying diatomaceous earth to stop them from doing more damage.
natural pesticide choices
Diatomaceous earth stops crawlers, and soap and oil can stop flying insects.

Further, you can’t be perfect at IPM cultural practices, as hard as you try. For example, I’m pretty sure tomatoes are not native to my region. But I want a vegetable garden. I have to work harder to keep tomatoes healthy than I do the ornamentals (and weeds!) native to New Mexico. I also can’t control the weather. I’m certain many of our bug (and snail!) trouble occurred during frequent night rains and cool, cloudy days. Our plants aren’t adapted to that. Finally, we spend most of our time on weeds – mowing, pulling and preventing. But we can’t control all of the weeds, nor can we control what our neighbors do with weeds or chemicals.