Any gardener will know that keeping pests under control is vital if you want healthy, beautiful plants in your garden. That’s why many use pesticides to protect their plants.
But chemical pesticides have a negative impact on the environment. They disrupt the ecosystem and reduce biodiversity by killing certain insects. Many also impact on non-target species, which means those insects that aren’t pests, such as bees.
They also disturb the microbial community in the soil, which makes the soil less healthy. Many of these pesticide chemicals will persist and build up in the soil. And when it rains, they get washed away and make their way into waterways, where they can kill aquatic life. (Zhou et al., 2024)
While some of the worst chemicals have been banned in the UK, many others which have a negative impact on the environment are still allowed. If you look at the labels of commercially available pesticides, they will state that they are very toxic to aquatic life.
So clearly, using these pesticides aren’t an option if you want to be an eco-friendly gardener. The good news is that there are many ways to control garden pests without using these harmful chemicals.
Here we provide you with 5 tips for eco-friendly garden pest control.
1. Encourage Beneficial Insects To Your Garden
In nature everything is balanced, which you can use to keep garden pests under control. The species we consider pests are part of the food chain, so there are predators that will eat them, which is where nature’s balance comes in.
So to keep pests to an acceptable level, you need to encourage these beneficial insects to your garden. Those predators include ladybirds, lacewings, predatory wasps, spiders, hoverfly larvae and predatory beetles.
But how can you attract them to your garden? The answer is food and shelter. Most beneficial insects don’t just eat pests, but are also partial to nectar or pollen, so planting flowers is the best way to attract them. The more variety you have in your garden, the more of these beneficial critters will come.
Here are some of the best flowers to plant:
- Marigold
- Oxeye Daisies
- Fennel
- Asters
- Honeysuckle
- Dahlias
- Cosmos Dill
- Golden Rod
- Clanedulas
- Hydrangea
- Lavendar
- Caraway
These will attract quite a lot of different beneficial insects, including ladybirds, lacewings, minute pirate bugs, soldier beetles and hoverflies.
Ensuring you have a variety of shrubs and trees in your garden will attract further predatory insects such as spiders. Basically, the bigger the diversity of plants you have, the more diversity in insects you will get.
We created a wildflower meadow in our garden, which is a great way to attract all sorts of useful insects. While it was a bit of work, it was well worth the effort.
If you want to do the same, these are the steps to follow:
- Select an area – you want a sunny spot – the size will depend on the size of your garden, so it might just be a small area
- Remove the grassy topsoil – we took off about 5cm (2 inches) – autumn is the best time to do this
- Dig over the soil and remove any weeds – this can be hard work, especially if you have stubborn perennials such as dandilions
- Rake through the soil – this will prepare it for sowing the seeds
- Sow your wildflower seeds – make sure you get native wildflowers as they are best for wildlife
- Press in the seeds – walk over the area to make sure the seeds have good contact with the soil
- Cover with netting – many birds like seeds, so cover it to keep them from ruining your hard work
- Check on the netting during winter – birds might get trapped in the netting, we had a curious robin that needed rescuing
- Remove netting in spring – once the first green shoots come up, remove the netting and enjoy!
A proper wildflower seed mix must contain grass and yellow rattle to keep the grass in check. To maintain the meadow, we scythe it in late summer and go over with the lawn mower once in winter to keep the grass down.
For shelter, leave log piles and leaf heaps in your garden to give bugs and beetles somewhere to stay. A compost heap also attracts many beneficial insects.
Bug hotels, which you can buy, also provide a place to live for different insects, including lacewings and ladybirds.
Finally, you need a water source, especially in summer when it doesn’t rain as much. This can be a few bowls or saucers placed around your garden, which you need to keep filling up, to a wildlife pond.
We have opted for a wildlife pond, because it attracts even more wildlife as it creates a different habitat.
Since we have created the wildflower meadow, hung up bug hotels and left log piles and leaf heaps in the garden, we have not had any issues with pests on our vegetables. Our garden is in perfect balance where pests don’t affect our yield and all that without any chemical pesticides.
2. Use Companion Planting To Keep Pests Away
Another way to keep pests away from your plants without using pesticides is companion planting. This gardening method has been used for hundreds of years and is most often associated with organic gardening.
The concept is quite simple: you plant different plants in the same bed. So if you grow vegetables, rather than having one bed with carrots, one with tomatoes and one with garlic, you grow them together. You choose companion plants that will benefit each other.
While there isn’t much scientific evidence about companion planting out there, some research has been done. One study looked at the benefits of planting cucumber and wheat together. It found that doing so increased the yield for the cucumbers. (Chang et al., 2017)
Depsite the lack of hard scientific proof, many gardeners, including us, swear by this gardening method. And there is plenty of anecdotal evidence that makes it worth giving it a go.
And it makes sense. We know that nature always provides a balance so that no one species can take over (well, this failed with us humans). And if you look at nature, a variety of plants grow in the same place. You won’t find any habitat that consists just of one plant, unless humans are involved.
While this gardening method is mostly used by vegetable gardeners, you can also use it if you grow ornamental flowers. Here are some plants that work great as companion plants:
- Garlic, onion and chives – these plants from the allium family have a strong scent which deters/confuses some pests, including aphids
- Lavender, thyme and marigold – another set of fragrant plants that will deter pests and attract pollinators
- Nasturtium – aphids love this plant, so you can use it as a sacrificial crop, which means you plant it next to a plant you want to protect
- Mint – another fragrant herb that deters pests thanks to its scent, but you’re better off planting it in pots as otherwise it will take over the bed
I use companion planting a lot in my vegetable beds and I haven’t had any issues from pests. My favourite combination is carrots and leeks, because they deter each other’s pests.
But I also like to plant garlic and spring onions with other plants as they deter many pests.
3. Create Physical Barriers
An easy eco-friendly garden pest control method is to prevent them from getting to your plants. Physical barriers won’t harm them, but will protect your plants.
Depending on the pest, there are different barriers that you can put in their way.
Insect Mesh
For smaller pests, insect mesh is the thing to use. It’s very fine netting that will keep insects away from your plants. This is especially useful to keep butterflies and moths from laying their eggs on your plants.
Caterpillars are insatiable and can diminish a plant in a few days. But insect mesh can also prevent other little critters from getting to your plants.
And don’t worry, you don’t have to cover your plants all year round, only during the time that the pests are most active.
But what is important is that you leave some space between the mesh and the plant, otherwise the insects who lay eggs on them might still be able to reach them.
Of course, this type of barrier will also keep larger pests away, such as pigeons. So if you want to protect your plants from both small and large pests, insect mesh is a great choice.
Netting
Larger pests, such as pigeons and rabbits, can be deterred by covering your beds with netting. The holes in the net are small enough to keep the pests out, but not so small that helpful insects, such as pollinators, can’t get to the plants.
They are mostly a thread to young plants, as they will pick off all their leaves, which will kill them. Older, established plants should be able to cope with being nibbled at by these animals, unless there are too many.
We once lost all our broccoli seedlings to hungry pigeons. We didn’t realise they would eat them, so planted them out unprotected. When we got up the next morning, all that was left of the broccoli plants were the stalks.
If only we had protected them with netting…
Plant Collars
To protect against insects that lay their eggs in the soil at the stem of plants so that their young can feed on the roots, you can place plant collars around the stem. They are often called brassica collars, because this plant family is often attacked by such pests.
They are basically discs that you can lie around the plant to protect the soil. They come in different sizes and materials. Some can be reused, which are the best option.
If they are coated with copper, they will also keep slugs away, as slugs don’t like going on copper.
Once the plants are big enough not to be bothered by any pests any more, you can remove them.
Copper Mesh Or Rings
Slugs and snails are seen as one of the worst pests, as they can eat a whole plant in a night. When conditions are right – mild winter, wet spring – slugs and snails thrive and because of their sheer numbers, they can decimate several beds.
We have lost a pumpkin plant, a gherkin plant, two courgette plants and a French bean plant this year, because the slugs and snails just overrun our vegetable beds.
But as we have already said, they don’t like copper, so using copper mesh or rings to protect your plants will keep the slimy creatures away from your plants without harming them.
It’s a method we will definitely adopt after this year’s losses.
There are many eco-friendly gardening products that make your life easier without impacting on our environment.
4. Use Probiotics For Your Garden
Another way to keep pests from ruining your plants is to ensure that they are as healthy and pest-resistant as they can be. And this can be achieved by adding plant probiotics to your gardening routine.
We have millions and millions of microbes in our gut to support all manner of things, including the immune system, digestion and nervous system. This is called our microbiome. And plants also have a microbiome that helps them to grow healthy and strong.
There are three areas where microbes support plants: in the plant tissue, in the soil and on the foliage. (Pandey et al., 2022)
There are products that you can buy that contain probiotics for the garden that you can add to the soil or spray on the plants.
We would recommend a company called Mircobz. They are a family-run UK business who brew their probiotics right here in the UK from soil. We use their probiotic cleaners and gut probiotics and can’t recommend them highly enough.
This year, we will start using their probiotics for our garden to support our plants’ health and make them more resistant to diseases and pests. You can read about our first impressions with these products in our Mircobz garden probiotics review.
While this way of pest control won’t be immediately obvious, it’s a long-term approach that will ensure your plants are strong and healthy, which will enable them to withstand mild attacks by pests without any issues.
5. Practice Crop Rotation
Diseases and pests can build up in the soil over time. This means that if you then grow plants that are vulnerable to these in this soil, they will be at a disadvantage from the start.
Most plants can tolerate a small number of pests nibbling at them, but larger numbers can damage them, stunt their growth or even kill them.
To prevent pests and diseases from building up in the soil, don’t grow the same plants or plants from the same family in the same bed year after year. Instead, practice crop rotation, where you rotate the plants you grow around to ensure that different plants grow in the soil.
This is only possible if you grow annuals, as perennials won’t like being uprooted and replanted every year. It’s also a method that is largely used by vegetable growers, but can also be used if you grow ornamental flowers that are annuals or biennials.
The key piece of information to know is which plants are likely to suffer from the same pests. In most cases, plants from the same plant family will be vulnerable to the same pests.
That’s why most gardeners that practice crop rotation will use this criterium to decide where to plant their annuals each year.
Use These Methods Together For The Best Results
Each of these eco-friendly garden pest control methods will protect your plants without harming wildlife and the environment.
However, for the best results, use several or all of them in combination depending on the needs of your garden.
If you grow mostly fruits and vegetables, then using physical barriers, probiotics for the garden, encouraging beneficial insects and companion planting should ensure pests in your garden are under control.
Practising crop rotation is always a good idea if you grow vegetables.
For gardeners who enjoy growing ornamental flowers, I would recommend attracting beneficial animals, probiotics and companion planting to keep pests from ruining your flowers.
The more of these methods you use, the greater your chance to keep pests under control without using harmful chemicals. So why don’t you start them in your garden today?
