How to Control Garden Pests (Without Toxic Chemicals)
Aphids. Slugs. Even pill bugs? It’s so frustrating when you work hard to grow food in your garden and then these pests show up and eat all your hard work. How do you control garden pests when you don’t want to spray toxins on the food you and your family are going to eat?
Work with Nature to Control Garden Pests
There are lots of ways to control garden pests without resorting to toxic chemicals.
By working with nature you can control garden pests and reduce your workload without resorting to pesticides, nets, and other techniques that aim to eliminate the pest issue.
5 techniques to control garden pests
- 1Control garden pests with beneficial insects
- 2Create habitat for predators of the garden pests
- 3Plant polycultures – a mix of different plants
- 4Plant perennials
- 5Don’t try to eliminate the pests (Yes, you read that right!)
While each of these techniques will help on their own, none of them is a silver bullet.
When you see pests in your garden, the problem might not be the pests.
The problem could really be a lack of habitat for beneficial insects and predators, or an issue of planting too many annual vegetables in monoculture rows or clusters.
The techniques in this article will help you control garden pests and create a more beauty and bounty by improving the habitat around your garden.
There's a lot to take in, so be sure to check out my free, easy-to-print cheat sheet to help you control garden pests.
Do You have an Oasis Garden in a Desert?
Let me ask you a question – what is surrounding your garden and the broader area around it? Is it just a lawn with a few ornamental shrubs or trees here and there?
I see this type of setup all the time in my area. This creates what I call the “oasis garden in the desert.”
Your lawn and small number of ornamental shrubs and trees don’t provide much in the way of food, either for you or for wildlife. While it might look nice and make your neighbors happy, it is essentially a food desert.
The garden is the one place of abundance, and you are not the only one drawn to that abundance.
To control garden pests your garden needs to be part of a healthy environment. It can't be an oasis in the desert.
1. Control Garden Pests with Beneficial Insects
Lots of gardeners run into trouble by keeping so focused on growing yummy vegetables that they grow nothing else except for a few token marigolds or sunflowers.
And who can blame them? That’s the whole point of a vegetable garden, right?
The problem is, this provides lots of food for pests, (namely, your vegetables), but it offers little for the beneficial insects that would have eaten the pests.
Flowers will attract beneficial insects. Simply by planting a diversity of flowers in and around your garden, you can attract beneficial insects to your garden that will help you control garden pests.
As an added bonus, this will make your garden incredibly beautiful.
3 ways beneficial insects help you out
- 1Eating garden pests
- 2Functioning as parasites to the garden pests, ultimately killing the pests
- 3Pollinating your vegetables, herbs, and fruit trees
Permaculture Research Institute has a fantastic article covering beneficial insects and what flowers will attract them.
But if you really want to work with nature and take this a step further, I don’t recommend planting a random mix of just any flowers. Instead I recommend planting a variety of native flowers.
Why Native Flowers?
The reason is that most insects are specialists – they can only reproduce on or eat one specific plant. According to Bringing Nature Home by Douglas W. Tallamy 90% of plant eating insects are specialists.
If you only plant non-native plants, then you are just supporting the small percentage of generalist insects that can basically live off anything, when instead you could be providing habitat for a broader range of local critters that rely on local plant life to survive.
Since you’re not growing the flowers for food, why not plant native ones?
If you don’t feel like you have room in your garden for these flowers, consider making flower beds around your garden for these native flowers. In addition to adding beauty to your garden, this will promote beneficial insects and help control garden pests.
The National Audubon Society has a web based tool that can help you find flowers and other plants that are native to your area. For each native plant, this tool will also tell you what the plant provides for birds in your area and which birds are attracted to that specific plant.
I also wrote a blog post all about the benefits native plants can provide to your property.
Plant flowers - especially native flowers - around and in your garden to provide habitat for beneficial insects to help control garden pests. Beneficial insects will:
- Eat garden pests
- Function as parasites to garden pests
- Pollinate your vegetables, fruit trees, and other plants
Bringing Nature Home is a great book to learn more about using native plants and why they are important.
2. Create Habitat for Predators
No, I’m not talking about creating habitat for wolves, (as much as I might want to!).
The predators I’m talking about here are small predators such as birds, frogs, and snakes that eat the critters that eat your plants.
These small predators will help you control garden pests.
Depending on where you live, you might not want to create snake habitat. Here on the west coast of Washington State, I’m lucky to have no poisonous snakes. Garter snakes eat slugs here in western Washington, so I’m very happy to create habitat for them.
Control Garden Pests by Providing Shelter for Small Predators
Birds need trees and shrubs for protection from other predators and for nesting. Creating a pond is a great way to attract birds, and frogs.
Just make sure the edges are not too steep, so birds and frogs can easily get in and out.
If you don’t have room for a pond, consider a bird bath. My bird bath is visited by dozens of birds each day.
Try planting fruiting shrubs and trees to the north of your garden. These will provide shelter for birds without shading your garden.
If you can mix in some native shrubs and trees, you will get even more benefits.
If you live in a fire-prone area, you might want to avoid brush piles and instead focus on rock piles.
An alternative to a brush pile is to dig a small depression and place logs at the bottom and branches on top.
Make sure there are gaps between the logs.
Then cover this pile with soil, sod, and mulch while leaving the north facing side uncovered.
This is sometimes called an insect hotel, but amphibians and lizards will also use them if the gaps are large enough and they are at ground level.
Creating habitat for small predators will increase their numbers on your property, helping you to control garden pests.
In and around your garden create brush piles, rock piles, and other habitat features that mimic what you would find in nature. These provide homes for small predators such as birds, snakes, amphibians and lizards which help to control garden pests.
3. Plant Polycultures – a Mix of Different Plants
A polyculture is a garden with multiple types of plants mixed together in the same areas. This is essentially the opposite of a lot of mainstream gardening, where each crop has their own designated place.
You know what I’m talking about—lettuce in one row, carrots in the next, broccoli in the next, and on and on. This one-crop, one-place type of gardening is called a monoculture. This type of gardening is easy to plant and easy to harvest, but it often results in pest problems.
The trouble is, it’s easy for you to harvest but it’s also easy for pests to harvest.
Ok, let’s be honest. It’s an all-you-can-eat buffet for the pests.
Let’s fly around in their shoes for a minute.
What a Monoculture Garden Looks Like to a Pest
Imagine you’re a cabbage butterfly getting ready to lay your eggs. You’ve got well over two thousand eggs to lay, and if all goes well, each of those eggs is going to grow into a very hungry caterpillar. You need to lay your eggs somewhere with lots of food nearby to feed those growing young’uns. You are looking for brassicas. Broccoli. Cabbage. Kale.
Oh my gosh, what’s that smell wafting in the southerly breeze? Broccoli flowers! Loads of it! The scent is unmistakable.
You flutter in for a closer look, and sure enough, you’ve struck gold. One broccoli plant after another, right down a tidy row.
You’ve got plenty of space to lay your eggs in clusters under the plants’ leaves, and once those eggs hatch, the little’ns will be able to feast through the larval stage right into adulthood.
What happens next?
Well, chances are more cabbage butterflies will come and lay their eggs on the broccoli, since they’re so easy to find.
So we’ve got thousands and thousands of eggs here, just waiting to turn into thousands of very-hungry-caterpillars. And once the eggs hatch, all those larvae can easily move from one broccoli to the next all the way down the row, since they are all planted right next to each other.
Those lush broccoli plants, once so promising, will become mere skeletons, leaving little or no harvest for the hapless grower.
The cabbage butterflies, on the other hand, are doing better than ever.
What a Polyculture Garden Looks like to a Pest
Now imagine we mix it up a bit.
What if the garden had a broccoli plant, but next to it was a pepper plant and next to that was a lettuce and next to that was an eggplant, and only then, finally, there was another broccoli plant.
What happens if you’re a cabbage butterfly flying over this garden?
That broccoli plant is hard to find!
The different scents are all mingled in the air together, and the plant leaves are varied as well. It would be so easy to fly on by and miss the broccoli plants altogether. But even if you do find some broccoli and lay your eggs on it, when your larvae hatch they will be stuck to that one plant with nowhere to go once it is used up.
Plant Polycultures to Control Garden Pests
Harvesting and planting can be a bit more complex, but you don’t have to change things up too much to see real improvements. Just by alternating between two different plants in a single row you can reduce your pest issues.
You don’t want to make life too easy for your pests. You want to confuse them. Confound them. Mix it up a bit in your garden, and you will mix them up too.
This is the best way to control garden pests. If you want to learn more about how to plant polycultures I recommend checking out Gaia's Garden by Toby Hemenway. Gaia's Garden provides far more information than this blog post can cover on polycultures, and other techniques that can help you control garden pests.
Plant polycultures in order to confuse pests and support a wide range of beneficial insects and critters. Check out Gaia's Garden by Toby Hemenway for help planting polycultures in your garden.
4. Plant Perennials
Our gardens are almost always planted as a mix of annual vegetables—plants that we re-plant at the beginning of each growing season. This can result in a lot of great food for us, but it also means our gardens reset every year.
Often, we go through and put the garden to bed each fall.
You may have a fall and winter crop, but you are still likely leaving most of the garden bare over the winter.
This means you must replant every spring, but it also means you have to rebuild your beneficial insect population every year, since they can’t overwinter in your garden.
Praying Mantis - One of Many Beneficial Insects Supported by Planting Perennials
For example, praying mantis (an awesome predator insect that feasts on the pests that eat your garden,) lay egg sacks on dead standing plants that then hatch in the spring. If you knock down or remove all your dead standing plants, there is nowhere for praying mantis to lay their eggs in your garden.
Woody perennials create great habitat for critters like praying mantis through the winter.
Annuals can work but often we clear these plants to create compost or make room for new plants.
Perennials are generally left where they are.
Planting perennial plants in your garden will help ensure there is enough beneficial insects each year to control garden pests. The praying mantis is just one of many beneficial insects that your perennial plants will support.
You might be thinking that this all sounds great but I only want vegetables in my vegetable garden.
What if I told you that you could grow perennial vegetables that would come back year after year without being replanted?
Grow Perennial Vegetables
In my post on perennial vegetables I give examples of perennial vegetables. One classic example that you may be familiar with is asparagus, but there are many other perennial vegetables that you can grow in your garden.
I highly recommend Eric Toensmeier’s great book Perennial Vegetables: From Artichoke to Zuiki Taro, a Gardener's Guide to Over 100 Delicious, Easy-to-grow Edibles. This book lists a wide range of perennial vegetables in all climates found within the United States and is one of my top go to gardening books.
Start small and add perennial vegetables to the ends of your garden beds. Then add a few more to the north side of your garden - especially tall perennial vegetables like asparagus.
Overtime, you can experiment adding more to your garden. The result will be better habitat for beneficial insects, and other critters like frogs. Plus you will save time each spring by not having to replant your entire garden.
This will increase the population of beneficial insects and other critters helping you to control garden pests.
Add perennial plants around your garden and consider planting perennial vegetables in your garden. These plants will support beneficial critters and help to control garden pests.
5. Don’t Try to Eliminate Pests
This technique may be the most controversial, but it is also one of the most critical to successfully control garden pests. Trying to eliminate pests is like running on a treadmill – you never get anywhere but you still have to work hard.
Why is this? Can’t you just eliminate a pest and be done with it?
The pests will always come back from the surrounding area and trying to eliminate the pests every year will prevent their predators from ever building up enough numbers to control them.
And if you use toxic chemicals every year, you will kill off most of the good critters along with the bad, essentially wiping out the predators that would have helped keep your unwanted critters in check.
Here’s how it works.
Predators’ populations always lag behind the pest populations. When you hold back from trying to eliminate the pests each year, you allow the predators to build up and naturally control garden pests.
This won’t eliminate the pests, but it should keep them from causing too much damage--especially if you also implement the other 4 techniques outlined in this article.
Ultimately, you need to be okay with losing some of your harvest to pests each year, and accept that some of your harvests may be slightly damaged. It is okay if your greens have some holes in the leaves—it won’t hurt you.
The choice for you is between working with nature to reduce your workload, or continue to run on the treadmill.
Don't try to eliminate your garden pests. Instead strive to bring your garden into balance with nature by creating homes for beneficial insects and critters. You will still see some pests but they won't destroy your garden. Be okay with some loss and some damage to your harvest.
Control Garden Pests by Moving Beyond the Oasis Garden in the Desert
If you implement all these techniques, you will end up with a garden that combines annual and perennial vegetables intermixed along with herbs and lovely native flowers attracting beneficial insects.
You may also have some fruit trees and berry bushes to the north of your garden, and perhaps small berry bushes or strawberries on the other sides, where they can provide habitat for beneficial critters while also generating abundance for your family and community.
You’ll also find some brush piles or rockpiles that texture the landscape, plus perhaps an insect hotel or two.
If you follow these steps, your garden will explode with life, and your pest problem will drop off dramatically. You can use a design system called permaculture to help you get this all setup.
Are you ready to take back your garden from pests and reduce your workload?
What works for you? How do you control garden pests? I'd love to hear from you in the comments on how you control garden pests and your experience with these techniques.
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