As summer rolls in, our gardens are full of life, both the good and the bad. Each has their place, but only when a balance can be struck: soil, water, light, and our plants—the integral components of a healthy garden—working in perfect harmony to produce the goods. I firmly believe that the “bad guys” only roll in when one of those components is out of whack.
Under normal, ideal, high-functioning conditions, our plants and our gardens can resist and maybe even repel insect outbreaks. But look at my garden—it’s an infinite web of endless interactions that’s virtually impossible to stay on top of a hundred percent of the time. Mistakes happen, and those balances shift, bad guys roll in, and we need an edge to keep them at bay, to give our plants a chance to thrive.
Chemical solutions do exist, but at much too great a cost. Not in the actual sticker price, but in the systemic, lasting damage they do indiscriminately to all organisms, including us. And this is why I love gardening the most—because the solution comes from making something ourselves: a true DIY natural pest spray that’s safe for our gardens, safe for us, and it just works.
Getting rid of insect pests shouldn’t be expensive, nor should it be a health hazard. There’s only three ingredients in this stuff, so making it’s a breeze. We’ll go over how to make it and why it works so well.
Look, let’s take aphids and all their associates out of the equation this year—safely.
So, like we said, your garden is a balance of parameters designed to allow your plants to thrive. Throw one of those variables a curveball, however—well, you better watch out. Excess nutrients, improper watering, or poor air circulation—those things can and will be met with more than just the immediate physiological response, namely, insect outbreaks.
Like adding insult to injury, insect pests seem to pile on when there’s already something going wrong with our crops. It’s uncanny, as if the poor conditions weren’t bad enough, things such as aphids, spider mites, whitefly, and more tend to attack our plants when they’re already down.
As organic growers, we want to go back to that perfect balance where our gardens are thriving, and I believe that starts with fixing the environmental parameters with a root cause in the first place. Don’t fertilize or water excessively, make sure that you have proper and good drainage, and plant your crops with adequate spacing between the plants and the rows. Once these factors are looked after and taken care of, most plants, even the lush ones, can become as pest-resistant as this garlic here. And it’s only then that we can start going on the offensive against our garden nemesis.
Okay, you’re fed up with all the bugs—I don’t blame you. It’s time to take action. We’ve put so much time and effort into our gardens up to this point; slowly losing them to an infestation is not an option. So, let’s grab our three ingredients and make our spray.
The exact recipe to make this spray hasn’t changed for me in over a decade—there’s still just three ingredients: you’ve got your water, you’ve got your castile or natural soap, and you’ve got your vegetable oil. While the list of just three basic ingredients keeps this formula simple, the proportions make it even simpler.
Start off with one liter of water as a base, add two tablespoons of the natural or castile soap, and then 2 tablespoons of vegetable oil. Mix it all together, and that’s your spray. It just doesn’t get any easier than that.
So, let’s expand that a little bit and have a closer look at what each ingredient does for the mix.
First up is water. Now we’re just simply using water as a base, a liquid vector that acts as a conduit to disperse our active ingredients. Regular tap water works just fine, and I’m using one liter for this mix.
Next, we have the major component, the active part of this formula, and that’s the natural or castile soap. Now, castile soap is a completely vegan type of liquid solution made exclusively from plant products. Traditional soaps use lard and animal fats, but castile soap is all veggie-based. In addition to that, this type of soap is free of dyes, synthetics, perfumes, or any harmful systemic chemicals. If you can’t find pure castile soap, just grab natural plant-based soaps that are dye and perfume-free; they should have the same effect.
Okay, great, so what is it that makes this stuff our main active ingredient? Castile soaps work to kill soft-bodied insects such as aphids by washing off and dissolving their protective coatings. With nothing to hold the moisture in, the insects simply desiccate and dry out. It’s very effective.
And the last of the three ingredients for this DIY recipe is vegetable oil. Canola, olive, corn, grape seed—they’ll all suffice, and these vegetable oils all work by themselves to suffocate insects that come in contact with them. But its main function in this mix is as a spreader-sticker. The vegetable oil helps our soapy mix to better stick to the plants as well as to our target insects. The addition of vegetable oil increases the efficiency and the effectiveness of the overall spray. Two tablespoons to match the soap is all I use.
Give the mix a good stir, and it’s ready for use right away. The vegetable oil will eventually go bad, but I’ve used mixes that were well over two months old, and they still work just fine.
Now, this spray is a contact-only, highly specific application, and this is by design. We’ve chosen not to use systemic chemicals because of the collateral damage they cause. So, broadcasting this spray indiscriminately wouldn’t make sense.
The beauty of this solution is that it doesn’t linger, and it doesn’t accumulate poisons in the soil or us. As a highly targeted solution, there’s a right way to apply this spray and a wrong way.
First, this stuff isn’t used for prevention; we don’t broadcast it all over the garden in the hopes that aphids never appear—that’s not how this solution works. This natural spray is designed for current outbreaks or hot spots as you see them; it’s only used to help the grower reclaim his or her crops or garden in the event of a pest explosion. It also works best and is way more effective when the population of that pest explosion is manually lessened.
So, I like to blast the affected plants with water first to remove as much of the pest population as possible. After that, come in hard with our DIY solution, spraying both sides of the leaves and stems. This combined effort is going to have the maximum effect. I let the spray leaves sit for a day and wash it off the next morning.
The spray is not necessarily phytotoxic; it shouldn’t hurt your plants, but the oil and the soap can clog the pores of the leaves, and that’s definitely going to cause some damage. The spray works on contact and is most effective within the first hour; it’s not designed to linger on the leaves. There’s no purpose for it, so play it safe and wash it off.
In fact, like any spray that you use in your garden, always do a test leaf first. Worst case scenario is to spray the leaves in the hot sun and let it sit there and dry for one to two days; you always want to test; you don’t want to dose an entire plant if it’s going to have an adverse reaction to the solution.
Repeat spraying every two days until that pest population is gone, and that’s it—a simple solution to a simple, albeit annoying, problem. We did cover a few key things, though, so let’s recap so we don’t miss a thing.
Big or small, when we plant a garden outdoors, it becomes part of a bigger ecosystem, and the balance and harmony are kept in check by a web of infinite interactions. Once there’s stress or pressure, the response is physiological by the plants, and signals are given off for the pests to move in. Annihilating those insects with chemicals is not an option, as those chemicals do far more damage long-term, and that’s way too dangerous for our soils and for us.
Fortunately, making our own safe and natural DIY insecticide spray is both easy and inexpensive. Taking one liter of water, add in two tablespoons of castile or natural soap, and match that with another two tablespoons of vegetable oil. Mix well, and that’s it.
For application, this or any spray works best when the bulk of the insect population is lessened. The easiest way to do this is to spray them off manually with water. After that, this solution can be applied every two days until the outbreak is gone, washing off the leaves with clean water on the days in between.
Nobody likes insect outbreaks; it’s so disheartening to see all your hard work just being munched away. But a healthy garden has its own defense system, and it certainly doesn’t need us to broadcast dangerous, lingering chemicals everywhere.
A safe, natural, targeted solution should be all we need to get an edge and go back to that perfect balance where our plants are thriving.
