Your Best Organic Pest Control Options
Pest control can be one of the most frustrating aspects of growing, but it doesn’t have to involve a compromise on crop quality with the use of harmful pesticides. Rich Hamilton explains how when it comes to pests, a little ingenuity can go a long way.
Organic pest control can seem impossible to those who may have suffered time and time again with a particular pest that is affecting the overall yield or quality of your crop.
You may have tried every pesticide out there, from the ridiculously cheap to the eye-wateringly expensive.
Well, sometimes there is a simple answer to a problem, a natural answer that may work just as well if not better than a man-made chemical pesticide, which can do untold damage to your plant, the environment, and whoever you are producing your crop for.
There are three main paths to organic pest control:
- Predators to pests
- Sacrificial plants to attract and deter pests
- Home-made organic oils and sprays to control pests
Predators to Pests
First, you need to have a “predators to pests” attitude towards infestation. Keep it natural—there is a balance in the world, a cycle that takes and gives.
The introduction of a natural predator (beneficial insects) to the pests that are blighting your plants is sometimes a very effective natural way to control damage to your crop. This is formally known as integrated pest management (IPM), or biological pest control. One example of this is with the caterpillar problem I had in my own garden.
I had tried pretty much everything to stop the caterpillars from decimating my cabbages—I mean everything. A close friend of mine popped over one day, and we were sitting in the garden having a coffee. The sun was out and it was a lovely day, all very Middle England.
Sitting in view of the machine-gunned cabbages my friend said, “Caterpillar, right?”
“Right,” I said. “I just can’t seem to get anything to slow them down or get rid of them.”
“Oh, that’s easy,” he replied. “What you need is a bird table.” He went on to tell me that what I should do is place a low bird table in the middle of the cabbages, with a dried sunflower seed bird dispenser.
The sunflower seeds attracted finches to my garden, and as the bird table was low to the cabbages, the birds soon learned there were fat juicy caterpillars everywhere for them to feast on to their hearts’ content.
Over time I reduced the amount of sunflower seeds available and found that the birds still came to eat the caterpillars. Within a week, it was hard to spot one caterpillar and by the end of the month, they were completely gone.
To this day, the birds still come to check if there’s any left, which is great for me as they also gently fertilize the patch around the bird table with their droppings. (See: Combating Critters: How to do Battle with Snails, Slugs and Caterpillars for more tips on that caterpillar problem you're having.)
This ethos about considering a natural way to control pests can also be brought into a greenhouse, with the introduction of chickens, for example. Chickens love caterpillars; however, they do tend to trample over everything in the process. Or, even in indoor growrooms with an insect such as parasitoid wasps, which are a predator of aphids.
The second method involves using a variety of plants available to help with your pest control. Even the use of sacrificial plants are within the remits of the cycle, as it is part of the giving and receiving process of the world.
What’s a sacrificial plant? Sacrificial plants, or banker plants, are an extension of the companion planting concept. Not commonly used by hobbyist indoor gardeners, sacrificial plants are a great organic way to reduce and sometimes completely eradicate pests. There are two types: deterrent sacrificial plants and sacrificial plants.
A deterrent sacrificial plant is a plant (not part of your current grow) which the common pest currently attracted to the product you are producing doesn’t like. For example, a common pest for tomato growers is plant lice. Plant lice do not like chives or mint, in fact they will actively avoid it. The answer would be to plant a border of sacrificial mint around the tomatoes you wish to protect.
Breaking a few leaves regularly on the mint plants will increase the potency of the mints deterrent attributes for the plant lice, keeping them at bay. If you were to have an indoor garden, the best place to put a few mint plants would be in the usual opening and closing areas where pests are most common to come in and out of the environment, such as intakes, outtakes, entrances, air ports, and humidity control ports – your ventilation system, in other words.
A sacrificial plant is a plant that is normally used when you have already identified a pest problem. This is basically the opposite of the deterrent plant—it is a plant that the pests in question prefer, more than whatever you are growing.
A plant is put within the growing environment in close proximity to draw the pests away from your crop and onto the preferred sacrificial plant.
When the sacrificial plant has become infested, it can then be removed from the growing area, either to a place where no harm can be done or put back into the cycle to create enriched soil and energy for the next generation of plants.
This cycle of using a sacrificial plant can be repeated time and time again until the problem is at a manageable level, or in some cases completely eradicated from your growing environment.
Every insect or pest has a preferred and non-preferred plant which can be used. However, you do have to be careful to pick the right sacrificial plant for the crop you are intending to grow.
If you don’t do your research properly, you might end up using a deterrent sacrificial plant that will attract another type of pest that could potentially be worse than the pest that you are trying to deter.
Organic Oils and Sprays
The third path is homemade organic oils and sprays. As we touched on earlier, plant lice do not like mint. There are also a wide range of other natural products that plant pests don’t like. Garlic is a fantastic example. It is an antifungal, anti-bacterial, and general-purpose insecticide that is effective on whiteflies, spider mites, thrips, ants, aphids, caterpillars, and even deer.
Basically, a great all-rounder, it can also be used as a deterrent within indoor growing environments, on intakes, outtakes, openings, and closings of the growing environment. This can be refreshed every few days. The simple recipe for a garlic-based spray is one teaspoon of garlic oil to one pint of water with 60 milliliters of 100-proof drinking alcohol.
Take note that the garlic spray can also deter some beneficial insects and bugs if used on outdoor growing environments. There are other natural herbs and produce that can be more specific to problem pests.
Here’s a quick list of the usual pest suspects and what they do not like.
- Aphids – Garlic
- Caterpillars – Neem oil
- Deer – Capsaicin (hotter the better)
- Fungas Gnat – Cinnamon
- Leafminers – Coriander
- Mealybugs – Cloves
- Moles – Chili
- Spider mites – Garlic
- Thrip – Coriander
If you have a problem with pests, try a home remedy before you run off to buy the latest and greatest chemical off the shelf. You may be surprised by the results.
Written by Rich Hamilton | Writer, Consultant, Author of The Growers Guide
Rich Hamilton has been in the hydroponics industry for more than 20 years, working originally as a general manager in a hydroponics retail outlet before becoming an account manager at Century Growsystems. He enjoys working on a daily basis with shop owners, manufacturers, distributors, and end users to develop premium products.