How to Manage Pests in Your Garden with Beneficial Insects

There’s a lot to say about beneficial insects, but I don’t need to convince you that you want them in your garden.

You already know beneficial insects are… well… beneficial ha!

You know you want more of them, because you know they will help your garden thrive.

There are just some questions you’re struggling to answer:

• What do the good guys look like so I know not to squish them?

• How can I attract more beneficial insects to my garden and keep them there?

• What is safe to spray to kill the bad bugs eating my plants without harming the good guys?

What do the good guys look like so I know not to squish them?

I’m going to totally flip the script on this very common question.

Instead ask, what do the bad guys look like?

Why?

Only about 1-3% of insects are considered pests… that means the other 97% of all insects are actually considered beneficial.

Is your mind blown? Mine was.

So since there are some TEN QUINTILLION species of insects in the world… you can see how it would be a lot easier to get to know the 1-3% you don’t want.

Don’t get me wrong, it’s awesome to know what celebrity-status beneficials, like ladybugs, praying mantis, and lacewings look like at all stages, but you can quickly overwhelm yourself trying to identify every insect you see.

It’s much easier to just consider anyone who isn’t a foe to be a friend :)

The best way I’ve found to know if I should squish a bug or destroy a mass of eggs is to just find out if it’s a pest, rather than trying to find out what exactly it is.

I look at my plants, and if I notice chewed leaves, wilting, or I see many of the same type of insect, I do a quick google search for common pests of the plant I notice the problem with.

This search will yield multiple blog posts with pictures of the likely culprits, and from there I usually have my answer.

Then I can keep an eye out for that particular bug whenever I’m in the garden.

You will be amazed how much you’ll be able to identify common pests before they become a problem.

How can I attract more beneficial insects to my garden and keep them there?

Get them there with food. Keep them there with shelter. In short: PLANT FLOWERS!

Flowers provide both food and shelter, so planting flowers is a huge boon to your efforts. When at least 30% of your garden space is planted with flowers, beneficials will arrive en masse.

Letting violets and dandelions do their thing in the spring is also a huge benefit to your beneficials.

Many insects who prey on garden pests will also drink nectar from flowers, and flowers can also provide water.

Zinnias, for example, have a great shape for catching small amounts of rain and dew in their petals, which can refresh insects without creating a potential drowning hazard, or mosquito problem for you.

The added habitat of flowering plants is great for predatory insects, like spiders and praying mantis, because it gives them cover to do their hunting without being hunted by birds.

Flowers can also provide an alternative habitat for bad bugs. Nasturtium and Shasta Daisies are commonly used as an attractive “trap crop” to lure aphids away from other plants.

It doesn’t take long for those aphids to be discovered and devoured by someone further up the food chain.

Once the beneficials arrive, keeping them there becomes a matter of providing them shelter to survive the winter, so that the following year they can emerge and start working for you immediately.

Leaves provide the best winter habitat for insects, and should ideally be left right where they fall. If you don’t want to leave them where they fall naturally, you can still provide habitat by keeping them somewhere on your property after raking them up.

This flies in the face of conventional wisdom, which will tell you to remove all plant debris and till the soil to prevent pests from overwintering.

Well, slugs and cutworms aren’t the only ones overwintering in your leaf litter. Spiders, bees, butterflies, beetles, not to mention a whole host of compost-making critters like worms, all need the warmth of fall leaves to survive the winter.

Leave the leaves, and your garden will thank you for it.

What is safe to spray to kill the bad bugs eating my plants without harming the good guys?

That same search for “common pests” will also give you suggestions for how to deal with those pests.

Traditional advice consists of “remove debris and till the soil” (which to reiterate is a bad idea), and “use all-natural insecticides” like neem oil and diatomaceous earth.

The trouble is that using ANY insecticide will kill beneficial insects as well.

There is nothing you can spray that won’t also harm beneficials. There is no quick fix.

Well there is I guess… we’ve been using the “quick fix” for many years, and it’s destroying our ecosystem and killing the insects we rely on to pollinate our food, and feed animals higher up on the food chain.

The best, most sustainable way to control pests for the long term is to allow the ecosystem of your garden to take shape.

That means leaving the leaves and plant debris in fall so that good bugs and bad bugs alike can survive the winter in the shelter provided.

It means avoiding ALL pesticides, because even the ones that are safe for humans will kill your six and eight-legged allies in the garden.

And it might mean losing some plants. That’s ok. You’re in this for the long game. Today’s loss is tomorrow’s gain.

Three years ago after adding a massive amount of woodchips to my garden, the slugs thrived and ate all of my marigolds and rudbeckia. Every single one!

You could say I had a huge slug problem, but the year after, with no intervention on my part, the slugs had a huge ground beetle problem!

In most cases, if you let the ecosystem balance itself out, it will.

Important note though: There are of course always cases in which intervetion is neccessary to protect the wellbeing of your home and family. Termites will not “balance themselves out” and you don’t want a wasp nest where a small child plays. There are also some invasive species without any natural predators (japanese beetle and spoted lantern fly to name two).

Please recognize that this subject is extensive and nuanced, but the general guidelines above will help you maintain a beneficial insect population in your garden, and ultimately help reduce the number of pest insects on your plants.