If you’ve got insects and pests eating your plants and fruit trees, you’re probably here to find out how to make white oil to get rid of them. The good news is that it’s very easy to make this insecticide spray at home, with ingredients you already have sitting in your kitchen:
White oil is made by mixing 4 parts vegetable oil with 1 part dish soap. This concentrate is diluted in water and sprayed onto insects and pests. As a natural insecticide, white oil is good for killing and preventing pests like scale bugs, aphids, citrus leaf miners, and mites.
White oil is one of the easiest and most cost-effective ways to keep garden pests under control when you know how to use it to get the best results. A good white oil recipe and regular spray routine can make all the difference to your garden this season, which is exactly what I’m here to share with you today.
Easy DIY recipe to make white oil
To make white oil, all you need is:
- 2 cups of vegetable oil
- 0.5 cup of dish soap
- A jar or container with a lid that seals tightly
- A 32 ounce spray bottle or garden sprayer
- A funnel
- Tap water
Step 1: Make the oil and detergent mixture
Put 2 cups of oil into a jar or storage container.
You can use any vegetable oil to make white oil, such as coconut, cottonseed, olive, safflower, soybean, or sunflower oil.
Add half a cup of dish soap to the oil. The detergent is very important because it’s what makes the oil mix with the water in the next step.
** If you live in the UK, Europe, Australia, or New Zealand, try this dish soap instead of Dawn dish soap. It’s made by the same company (Procter & Gamble) but is sold under another brand name
Put the lid on the jar and make sure it’s sealed tight. Now shake the jar until the oil and detergent mix well and turn white, which is your basic white oil concentrate.
This concentrate can be stored in a cool, dry place and should keep for three months if the container is kept closed.
Step 2: Dilute the white oil concentrate in water
Use your funnel to fill the spray bottle or sprayer with tap water. You need to dilute some of the white oil concentrate in this water as the pure concentrate is way too strong, and will burn and hurt your plants if it isn’t diluted.
Here’s a table showing you how much white oil concentrate to add to the water in your spray bottle or sprayer, depending on how big your sprayer is:
|Amount of water||How much white oil concentrate to add|
|16 ounces / 0.5 liter||0.5 tablespoon|
|24 ounces / 0.7 liters||0.75 tablespoon|
|32 ounces / 1 liter||1 tablespoon|
|1 gallon / 3.5 liters||3.5 tablespoons|
|1.4 gallon / 5 liters||5 tablespoons|
As a general rule, dilute 1 tablespoon of white oil concentrate in every 32 ounces of water in the spray bottle. You can test different dilutions to see what works best for the pests in your garden and the plants you’re spraying – you might want to go up by half or even a tablespoon to increase the insecticide powers of the spray, if your plants can take it.
Close and shake the spray bottle well, to fully dilute the white oil concentrate in the water.
Weather conditions for using white oil spray
If you’re spraying plants and trees outside, you need to wait for the right weather conditions before you start spraying. You need a day and time that’s:
|Weather condition to spray white oil||Why it’s important|
|Dry||Rain will wash away your white oil spray, so wait for a day when no rain is predicted for at least 24 hours.|
|Cool to warm||A hot sun makes leaves more likely to get damaged or burn, so choose a day that won’t see temperatures above 86 degrees Fahrenheit (30 degrees Celsius).|
|Not windy||When spraying white oil, wind will carry the insecticide to plants and areas where you don’t want it to go. Be sure to use your white oil spray when it’s not windy.|
|In the morning||Spraying white oil first thing in the morning will make it less likely that you spray good insects, like honeybees.|
How to use white oil in spring and summer
The season and what you are spraying will determine how to use your homemade white oil spray.
How to use white oil in spring
Many insects ‘overwinter’ or take a rest in trees during the colder months, only to wake up and start eating your trees when the days get warmer. In spring, spray a generous amount of white oil onto the branches, leaves, bark, and in all the crevices of your trees, to kill any pests hiding in there.
How to use white oil in summer
Insects and pests that eat your trees and plants are usually most active in the warmer months.
White oil suffocates these pests when it comes into direct contact with them, but it also helps to prevent insects from laying their eggs there while the plants and trees are still oily from the spray.
In summer, spray your plants and trees from top to bottom to kill pests. Spray white oil directly onto the tops and bottoms of the leaves, and all around the branches, stems and bark. Try not to spray any flowers as you might end up spraying beneficial insects, such as honeybees or ground bees.
Regular white oil sprays every three weeks will help to kill live insects as they arrive, along with smooth-skin caterpillars and any eggs that are laid. This will keep pests under control as it breaks many parts of their lifecycle.
How to use white oil on citrus and other fruit trees
When spraying white oil on citrus trees and other fruit trees, you need to make at least two applications:
- Spray white oil onto the branches and bark of your fruit trees in late winter, after pruning and winter hardening. Never spray white oil onto citrus trees in late fall or early winter as they are weaker and more prone to injury.
- Spray white oil onto the leaves, branches and bark of your fruit trees again in spring, before the flowers bloom. Feel free to spray again whenever you see insects or pests such as aphids on your trees, but don’t spray white oil onto the flowers or fruit…
Don’t spray white oil on the flowers of your citrus trees as they are very sensitive, especially smaller citrus fruits. If you accidentally spray white oil on citrus flowers, you could end up with oil spots or bruising on your fruit later, which shows up as green or brown spots on the peel.
It’s best not to spray white oil directly onto fruit. If you use vegetable oil to make the white oil spray, then it is non-toxic and safe to eat (you already cook with these oils and use dish soap on your dishes). Just be sure to give the fruit a good wash before eating it.
If you have a problem with citrus leaf miners in your orchard, spray your citrus trees every seven to fourteen days and again whenever you see new growth.
What bugs does white oil kill?
White oil effectively kills the following insects and pests when sprayed directly onto the bug:
- Citrus leaf miners
- Fruit moths
- Lace bugs
- Plant bugs
- Psyllids (plant lice)
- Red spiders
- Scale insects
- Smooth-skin caterpillars
- Spider mites
- Young grasshoppers
White oil also kills insect eggs when it is sprayed directly onto the eggs, helping to break the insect’s lifecycle.
White oil spray is a cheap and easy way to control pests in the garden. It’s also natural, without harmful chemicals.
Make up a batch of white oil concentrate and store it in the shed, so you’re always ready to attack pests before they attack your precious plants, fruits, and trees.