Why I Want Some 'Pests' in My Organic Garden

Aphids, wasps, slugs, and moles aren't all bad. Some serve a valuable purpose.

caterpillars eating a cabbage leaf

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In my article on organic gardening mistakes, I spoke about how it is a mistake to try to eliminate pests entirely. And as a continuation of that article, today I thought I would share some examples of pests I have in my organic garden and delve a little deeper into why I want these creatures around.

Talking about "pests" can be misleading, since, like the term "weeds", it categorizes certain species into an undesirable group. But while these species can be problematic at times, it is important not to become too black and white in your thinking or to view these creatures as enemies.

Remember, though pest species may cause some problems for you as a gardener, they are also a crucial part of the garden ecosystem upon which you, as a gardener, depend. They each have their place within the system and play a role in its ecology. 

Wanting some pests around is not just a case of caring for all life and recognizing the intrinsic value of other creatures around us. It is also a practical decision, because a healthy ecosystem—which pest species help to sustain and support—makes things far easier for me as an organic gardener. 

Below are a few examples of pests that I allow to occupy my organic garden, with an explanation of why exactly.

Why I Want Some Aphids

aphids on a broad bean plant

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Aphids are a common pest. I often see them in my forest garden and around the edges of my vegetable beds. But this does not worry me. I see the aphids as welcome visitors on the whole, because they attract all the beneficial wildlife I want in my garden.

They are a crucial part of the food chain in my garden, eaten by a wide range of creatures. And having some around not only attracts the wildlife I want to keep their numbers in check, but also wildlife that provides a range of other ecosystem services.

In order to make sure that aphid populations are kept in check, I make sure that I have diverse plantings which welcome in as many of the creatures that prey on them as possible, and use companion plants in annual cultivation. But without the aphids themselves, these creatures would look elsewhere for a food source, so I do need some of them around, too.

When their numbers are not excessive and predation is possible, aphids are not really a major problem for healthy plants. When they do weaken a plant excessively, this is often a sign that something else is wrong. So aphids can also serve an interesting function—warning us to take a closer look at where plants may be failing to thrive.

Why I Want Some Caterpillars

Caterpillars, such as those of the cabbage white butterfly, are common pests of brassica crops. I do not want to lose my crops to these hungry caterpillars. But equally, I do not want to get rid of these butterflies and their caterpillars all together. These creatures too are food for a wide range of others that I definitely want around—birds, bats, frogs, toads, etc.

A pond situated behind my polytunnel, along with other wildlife habitats close by, means that several "defenders" have taken up residence, including some large toads that munch on these caterpillars in this undercover growing area before their numbers get out of control. I may lose the odd leaf, but not whole plants with this strategy.

Why I Want Some Slugs

Slugs are often viewed as the ultimate enemy by gardeners. But where I live, their numbers are kept in check by birds, small mammals like hedgehogs, amphibians such as toads, etc., and other important wildlife that aids me in my gardening efforts. 

Remember, too, that while some slugs will eat your plants, many live in your compost heap or in mulch layers on the soil, digesting dead plant material and playing their role in returning nutrients to the soil.

Why I Want Some Wasps

wasp nest

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Wasps may eat some fruit in my forest garden, taking advantage of holes birds have already pecked in apples and breaking the skins on a few of my plums. But while wasps can give a nasty sting, they are not usually overly aggressive where I live, and I have definitely learned to appreciate the role these creatures play in my garden.

Wasps feed their grubs on caterpillars and other insects and so can reduce damage to plants in a garden. These creatures too are just a natural part of garden biodiversity. By eating other invertebrates, they help to maintain a natural balance in the garden.

Why I Want Some Moles

I know that many people don't like moles digging up their lawn or making mounds in their beds or borders. But in my live-and-let-live garden, I am happy to give moles a home.

They do not usually harm plants, and actually do a lot of good—helping to aerate the soil, move materials around within the soil ecosystem, provide free fertilizer, and eat grubs and other things below the soil. I also take the soil from mole hills and use it in my homemade potting mixes for container plants.

Like everyone, I experience the occasional loss of a plant or frustrating garden problem. But on the whole, this is a small price to pay for an abundant and biodiverse organic garden.