Pests in Your Garden: What Can You Do?

Lenkland Photography

Here we are about a week away from the summer solstice and the longest day of the year. Your gardens are growing gangbusters, practically right before your very eyes. All looks good…the squash plants seem to double in size overnight, the peppers are setting blossoms, and your melons are starting to creep, and maybe you’ve even harvested your first zucchini. By all accounts, things are off to a great start.

But then you look a little closer…Ack!

Why are those cabbage leaves all curled up on themselves? Wasn’t there a melon plant in that spot yesterday? What’s eating holes in my tomato leaves? What is burrowing into my beet greens and leaving the leaves brown and papery?

Your garden has been discovered! You know the old saying…build it and they will come. There are pests in every garden, including beneficial ones. Generally, the beneficial bugs will keep the pests in check, especially if you have a diverse garden with many kinds of plants.

Diversity supports stability

Everyone knows the story of the Irish Potato Famine. The very short version:  the potatoes were mono-cropped, with little to no variation in variety, and when the blight hit, everything was wiped out, causing mass starvation. This is not likely to happen in one of your Sierra Gardens, because you plant multiple varieties and types of plants.

It is also good to understand the life cycles of pests in your garden. Most insect pests have natural predators, and generally, if you see pests, you will start to see the beneficial bugs that prey on them. However, sometimes the pest population has to reach a sort of critical mass before the beneficial ones show up, which can make folks nervous.

Having faith in nature’s life cycles

Years ago I worked with cotton farmers who were trying to convert from conventional (chemical controls) to organic farming. We sampled the cotton fields each week for pests and their predators. The pest populations generally had to peak before we would start seeing significant predators show up. Farmers would often panic and spray their crop, but having just a little patience and faith in mother nature’s ability to intervene can play a big role in pest control!

Tips for garden pest intervention

I tend to be a “hands-off” gardener, who doesn’t intervene much. But sometimes certain pests get out of hand and do some real damage. Below are a few common garden pests that I’ve seen in my travels to Sierra Gardens around the county, and some ideas for dealing with them.

The Pocket Gopher:

There’s probably no one among us who hasn’t dealt with these pesky little rodents. Gophers can do major damage to your garden, from the bottom up. If your garden or yard looks like the one pictured below, you’ve got a gopher problem. If you are seeing holes surrounded by freshly churned soil every morning (this is commonly referred to as a gopher “throw”), you’ve got a gopher problem. If you are happily observing your beautiful carrot row, and suddenly one wiggles back and forth and then whoosh…. disappears before your eyes, just like in cartoons, you’ve got a gopher problem.



Most people do not like the options for controlling gophers, the most effective of which is trapping and killing them. This takes a daily ongoing commitment, and you must psyche yourself up and learn to be one with the gopher. You may find that you actually get really obsessive about trapping, and the first thing you want to do every morning is check and clear the traps you set the previous day, look for any new throws and set new traps. There are traps on the market that can be quite effective but do require some repeated efforts on the gardener’s part. Trapping is clearly not for everybody.

Using poison to control pests is never something I encourage for a variety of reasons, but there are some “safer” options out there. I will forever maintain that trapping is the most effective control if done right. Still at a loss for dealing with gophers? Get a cat! Or a Rat Terrier. Or do something to encourage owl habitation around your property.

Here is a link to a variety of solutions available through Peaceful Valley Farm Supply.

Ground Squirrels:

Ground squirrels are different than the gray tree squirrels and spend their time mostly on or underground. These little buggers will eat your plants down to nubbins. They tunnel and live underground, but do much or all of their destructive work above ground. They can go over, under, and through just about any barrier you might erect for them.  I must admit that I have not found an effective control for ground squirrels unless you have a teenager with patience and a pellet gun. There are local pest control companies that offer ground squirrel control (again, be wary of poison in your garden), and there are a few options through Peaceful Valley that target ground squirrels.


Are very commonly found on brassicas and just about everything else, if not caught early they can do some real damage. Like many garden insect pests, they are sapsuckers. You often find them clustered on the undersides of leaves, but they also like to get into the tender new center growth of plants like cabbage and broccoli. The leaves will crinkle and curl into themselves in a way that doesn’t look natural, and unfurling them will reveal a whole world of tiny aphids. You often see ants in symbiosis with aphids, because aphids will excrete a sweet substance (called honeydew) which the ants are drawn to. So the aphids might not be immediately visible, but an ant infestation may be a good reason to look more closely.

There are controls for aphids. If the colony is small and on the surface, it can sometimes be sprayed off with a burst of the hose. There are products on the market for more stubborn infestations or for a safe and easy solution, mix a little dish soap with water and spray it onto the plants (a few tsp liquid dish soap per quart of water). There are a zillion home remedies on the internet, so find the one that works for you. If you do decide to spray your aphids, get down in there and uncurl the leaves and really get ‘em good. You need to make contact, as the fatty acids in the dish soap work by dissolving the aphid’s exoskeleton and ultimately dehydrating them.

Aphids do have a natural predator, which is the ladybug. They can be bought and released, but may or may not stick around. They may also just show up. I have been seeing them everywhere in my greenhouse and garden this year. Everyone knows a ladybug, but it is important to be able to recognize them in their various stages. See the pictures of the ladybug egg, larva, and pupa stages. If you see these on your plants, be very glad! 

Just for fun:

The Harlequin Bug

These are nasty little/not-so-little creatures (a type of stinkbug, actually) who show up out of nowhere and then suddenly you find yourself overrun. They are very common around here. Harlequin bugs are also sapsuckers and will cause your plants to wilt, turn brown and die. I have not found a lot of ideas in my research for “chemical” control of these critters. Generally, they need to be hand-picked off of your plants and destroyed. This can seem like an endless task, and may well be, but I do know folks who have dug in and managed to get rid of harlequin bugs this way. On large farms, they may plant a trap crop, meant to attract the bugs away from the main crop, but that is not really an option for home gardeners. Act quickly if you see these guys because you can get to them if you’re diligent!


Tomato Hornworm:

These are otherworldly looking green caterpillars with a hornlike tail, who blend so well with your tomato plants that you may look and look and never find one! But they will decimate your plants in a very short time. See photos below of defoliated tomato plants! They will also chew holes in the tomatoes themselves. If you walk out to your garden one day and your tomato plants are missing most of their leaves, you may well have tomato hornworms.  Another telltale sign is their poop. Actually quite large and noticeable, you may see it on the leaves and if you look you will find it all over the ground in surprising quantities. The best way to deal with hornworms is to pick them off the plants when you see them. They are masters of camouflage, so look closely. Drop them in soapy water or alcohol to kill them, or feed them to your chickens! They will be stoked.

Slugs and Snails

No photo necessary here, we’ve all seen ‘em. Slugs and snails generally live in the lush areas around your gardens and come out at night for a late-night snack. They feed by scraping and cutting, leaving large, irregularly shaped holes with smooth edges in your leaves. They also leave behind a slimy trail. One way of reducing the snail population in your garden is to reduce their habitat around your garden….keep the grass and weeds chopped down. They are soft-bodied mollusks who don’t like rough surfaces. Some people say coffee grounds, wood ash, eggshells, or gravel will deter them. Diatomaceous earth is a powder available at any garden store which can be used to create barriers. Though it feels like a fine powder, microscopically it has sharp edges and will tear up the soft bodies of the snail as they pass over it. Hand-picking them when you see them is always an option (also a tasty meal for some chickens). Small shallow containers placed around your garden filled with beer will also attract and ultimately drown slugs and snails. I generally prefer this method…why not show them a good time on their way to slug heaven?

Leaf Miners:

Very commonly seen on chard, beets, spinach, and can also affect other plants. You will not see these guys, as they get in between the layers of the leaf. But you will see their tunneling damage! Handpick the affected leaves and discard them in the trash (or feed to your chickens). Be careful…if the plant is badly affected, you don’t want to impact the plant’s ability to photosynthesize, so never remove all of the leaves, and never remove the most inner center leaves. Give the plant some time to grow out of it, and continue the process. You can get on top of the leaf miner with a little diligence.

I could go on forever about garden pests, but these are the ones I have most commonly come across in my travels to your gardens. This is some very basic information, and I would encourage you to use your powers of observation, and if you identify a pest, read up on it and educate yourself on their life cycles. This will go a long way to understanding how and when to control. And remember to keep your plants healthy and well-watered. A stressed plant is much more susceptible to pest damage than a healthy one.

Happy Gardening!